Are You On The List?

Do you get the email blasts from Sun Electronics? If not, you might need to go to the HOME page and sign up to find the latest bargains.

I am not in the sales department at John Kimball’s solar wonderland. I live 700 miles away and I find out about the latest deals via the emails, like everybody else.

Right now I have more solar modules than I know what to do with. Honestly, I have piles of them, so the listings of a super deal on panels doesn’t get me worked up. When I have needed panels for a project I have gotten excited and headed down Interstate 95 and loaded up the truck.

If you know Sun Electronics, you know there are always good deals on solar modules. If you know John Kimball, you know he sometimes goes bonkers with some crazy-cheap bargains!

This last email had some goodies known in the trade as BOS or Balance of System. That means the rest of the stuff, beyond just the solar panels. I got all worked up about the GS inverters in the latest blast. There is such a high demand for 48v inverters and charge controllers right now that they are hard to find and generally not highly discounted. Yet, there they were.

I am presently up to my ears in inverters with not just a live set, but a selectable hot standby. Otherwise I’d have been on the phone to Roberto in a heartbeat. I like the GS series because you can get 240 out of a single unit, unlike my Sunny Islands. And if you need more power you can “stack” them. Furthermore there are all sorts of options for grid tie, grid interactive, standby or standalone. They are super reliable, too.

From what I read, there may be a new version of the GS out. That’s the only reason I can figure for a clearance on such good stuff as that!

I don’t know if those units are still there or if there are some new bargains. Call Roberto to find out if you need some new gear or a spare.

–Neal

don't try this at home

STILL Not A Generator Plug

I used to get a magazine for electricians, EC&M, I think. Every month they’d have a photo layout of scary stuff that electricians and inspectors had come across.

Our recent “not a generator plug” photo would have gone well in that feature. While I was concentrating on the dangers of having the shiny bits electrified in a bootleg generator lashup, electrician Michael spotted a couple of other problems.

Note that either side of and below the 30 amp dryer socket, there are 110v duplex outlets. A basic 220 line consists of 3 wires. (Often there is a fourth wire, which is a ground wire.) Two of them provide the 220 (sometimes 240, but who’s counting). Take one of them and the third wire, known as the neutral, and you get 110v. What happened here was each hot “leg” (I don’t know why they are called legs. I just accept it and suffer no anxiety over the matter.) was connect to an outlet pair to provide some 110, if needed in the barn where this is located.

I doubt that anything was ever plugged into these particular outlets, but Michael noted that there is no fuse or circuit breaker in the mix, potentially allowing a lot more than the usual 15 amps through these outlets. The problem isn’t so much with plugging A cord into AN outlet. Michael has worked in hurricane country and observed the tendency that folks seem to have of plugging a LONG and LIGHT duty 16 gauge cord into such a plug or directly into the generator. Then there is one or more outlet strips on the far end of the cord with all manner of things connected, exceeding the AMPACITY (remember that word?) of the wiring. Fire ensues, much to everyone’s disappointment and dismay.

What Michael could not know, from the photo, but probably suspected, the generator is a large tractor-driven model that puts out a whole lot more than 30 amps, so even the big socket was in danger or a meltdown. There’s that AMPACITY business, again! We won’t even discuss the cable that was used between the generator and the not-a-generator-plug!

That might give me anxiety.

–Neal

don't try this at home

This Is NOT a Generator Plug

It is getting to be that time of year, when a lot of people think about getting a generator in case there is a hurricane.

A permanently wired generator eliminates dealing with cables.

Even if you have solar, it is a good idea to have a generator for times of extra load or for equalizing batteries. There’s also no guarantee all your modules will still be where they were before the storm, once it all settles down.

“Hubbell” or twist-lock connectors won’t fall out if someone trips over them. The generator side will have no exposed “hot” prongs. The cord to the house loads does not have any power on it until you plug it in. On the house end of the cable, there will be no exposed prongs, just like you see on the white cabinet. The house connector will have the exposed prongs, which are safe until you plug in the cord and will remain safe because the connector covers everything. There are many sizes and configurations of twist locks. These are 240v, 50amp “California” connectors.
A Hubbell connector for 120v and 30 amps…a common size.

The thing about generators, though, is that so few people do it right. You need a proper generator plug and a transfer switch. The transfer switch lets you select the power company or the grid as your power source. It also prevents your generator from backfeeding into the neighborhood, possibly killing a lineman, but most certainly killing the generator. If you have solar, your inverter may also have a transfer switch built in to allow the generator to take over. That’s all well and good, but where people run into trouble is how they connect the generator to the house.

A lot of people take what is essentially a double-ended extension cord and plug into a wall outlet for a small generator or a 220 socket normally used for the clothes dryer. What’s wrong with that? First of all, if the plug is not securely plugged in, it’ll soon be on the floor where someone might touch those energized prongs. Second, if the meter is not pulled or the breakers pulled, power can go out into the world. A proper generator plug uses a “Hubbel” or twist-lock connector that won’t fall out and the generator side of it has no exposed contacts.

If the power goes into your house by a socket like this, the hot plug from the generator is going to carry deadly voltage. And it is exposed when not plugged in! If you manage to get it plugged in without killing yourself, note that the straight prongs do not lock and it can easily come unplugged, exposing the deadly voltage. This is an outlet, which is fine for plugging in a clothes dryer or welder, but not a safe place to plug in the generator.
If your generator connection is outdoors. It should be in a water resistant case that closes off when not in use.

Many years ago we had a storm that was unexpectedly fierce and the power was out for weeks. I did not have any provision for a generator, but I had a big old diesel rig out in the barn, so I improvised. I brought the power in, hardwired to one of the outside a/c disconnect boxes. The main breakers were pulled and I removed the power meter, replacing it with a protective sheet.

Was the power company upset that I broke the seals and snatched out the meter? No! They thanked me for not killing them.–Neal

July solar arc at the Solar Shed

A Different Angle

Traditionally, we’ve been told to point our solar arrays to the south.  There were guidelines on the angle from horizontal, too.  Pretty much all of this is open for question, now.

You may have noted my recent posts on the arc the sun travels and my experiments with a vertical array.  There’s more to it.  Instead of my next expansion of the Solar Shed being linear along the airstrip, I’ve decided to make a portion of it extend to the north, with a north-facing slope for the solar roofing tiles.  I had thought to add just a carport for the EVs on the backside, but the Man Cave needs room for a fitness center and other activities.  Careful observation has shown that a north slope could pick up quite a bit of morning and afternoon sun.

It’s not just me, thinking this way, and people who don’t have a roof with a perfect southern exposure needn’t fret when wanting to add solar.  Recent studies in Australia have found that splitting the array between northeast and northwest is a good plan.  Bear in mind that the Land Down Under is upside down, or we who dwell in the Northern Hemisphere would say southeast and southwest.

Why?

Well, think about when you use your electricity and the possibility that maybe sometimes you are making too much and other times not enough.  In grid tie situations, there are sometimes limits on how much the power company allows you to export.  Also, places that have high concentrations of solar, have run into problems when everybody is making max power at the same time.

Typically, we use the most power in the morning and evening.  Think about it.  You roll out of bed and go turn on Mr. Coffee.  You stumble into the shower, which activates the water heater.  You pop a couple of frozen waffles into the toaster or nuke a frozen omelette.  You might even fry up some bacon and eggs on the stove.  After breakfast, you toss the dishes into the dishmasher (yeah, that’s what we call it) and off you go to work.  Lots of electricity was consumed.

Maybe you set back the thermostat during the day, so it cycles a little and so does the fridge.  Not much goes on during the day.

You come back home, after work, and hit the thermostat.  Turn on the tube for the evening news.  Run pretty much everything in the kitchen to get supper ready.  Maybe do a load of laundry.  More water heater and more dishwasher.

Lots of power in the morning and evening.  If your arrays (instead of array) pick up more power early and late, it can be self consumed and not run as much back into the grid.  This minimizes the chance of exceeding a limit.  It is very beneficial in areas where they pay you, say, 4 cents for your power and charge you 12 cents to get it back.

There are benefits off grid, as well.  I see in my own array that my batteries sometimes are just begging for some morning sun, especially these mornings where the A/C needs to really get buzzing early.  Here, we define a warm day as 80 by 8 and a hot day is 90 by 9am.

Then, late in the afternoon, that afternoon sun is way off the axis of the south array, but really cooking the back side of the house, placing maximum load on the A/C.  Not only that, I get hungry about then and all the kitchen stuff comes online.

At solar high noon, my batteries are pretty much topped and more power is being generated than is being consumed.  That means I am just throwing power away.  Part of that will be alleviated with my next battery upgrade and that will allow me to put more load on the system.

Another angle on this, so to speak, is time of year output.  Come winter, the sun will lean a bit more to the south.  The array on the north slope may get little or even no direct exposure to the sun.  They will put out a bit because of incidental insolation, but the lower angle on the southern array will produce more power due to closer alignment to the sun.  Then there is the matter of load.  I rarely run the A/C in winter.  I suppose I could run the heat pump.  That would save on the efforts involved with firewood.  Firewood is good exercise, badly needed exercise, but there may come a time when I can’t handle that anymore.  The problem with heat pumps, which gas companies are quick to highlight, is that they don’t pump much heat when it is truly cold.  That’s why we have a wood furnace boiler out in the backyard.

For now, though, summer is our high power consumption time. Right now, probably about 90% of my solar output is going to air conditioning and that is more than the rest of the loads combined.

Therefore, I propose that you carefully study what your loads are, and when, and you might find your options for an effective solar array are better than you thought.–Neal

AMPACITY

AMPACITY. That’s our word for the day. If you think it sounds like a mashup of “ampere” and “capacity”, then give yourself a gold star. That’s exactly what it is.

So, what’s it all about? If you are moving electricity around with wires, then you need to understand that you need to choose the wire of the right ampacity. Really thin wire could melt and start a fire. Too thin wire would work safely, but you might lose some precious watts to resistance. Wire that is too fat is fine, but expensive. Choose the right wire and you will end up with a system that is safe and cost effective.

Here’ a tip: Put wire spools on a rod or pipe in the rafters. They will be out of the way, but easy to spool out whatever you need. Still plenty of that strange green solar cable, but the 00 gauge spool has run dry, thanks to the addition of two very large batteries to my system. At $4.50 per foot, that 250′ spool may have to stay empty until I actually need some.

Lower voltages require thicker wire of a higher ampacity than higher voltage. In my house, most of the outlets are on 20 amp circuits delivered by 12 gauge wire. This might sometimes be listed as 12 AWG. Some houses are wired with 15 amp circuits and 14 gauge wire.

Battery cables tend to be thicker on 12 volt systems than on 24v or 48v systems. Why? To get the same number of watts (Watts = Amps X Volts) it takes 4X the amps on a 12v system than on a 48v system.

On a household 120vac system, it is ok to lose 2 volts in the resistance of the wire, but losing 2 volts between the battery and inverter might mean the inverter will do a low voltage shutdown.

I have a situation at my house where the wire I have buried is only good for 40 amps and I can now easily supply 50 amps at 240vac. There is a bunch of stuff in the ground along the path, so I will be very careful not to hit water or sparks if I dig a new trench, but the real scare is the price of wire, these days. Since the beginning of the year, the wire that I need has jumped to $902! Whoa!

A peek into Neal’s miscellaneous wire bits drawer. The white is really good 10AWG solar cable. The red 2AWG piece is plenty for a golf car battery cable. The black piece of 00AWG will work fine for a battery cable on the big batteries in the house system. There is no such thing as scrap wire at my house!

Now, mind you, that’s for copper wire. What if I check the ampacity of ALUMINUM direct burial cable? Turns out, that’s a couple of steps thicker (wire usually increments in 2 points), but the price is only $258. That sounds a whole lot better. I don’t like aluminum wire, but I may make an exception!

Ampacity tables are all over the internet. What I have run into with them is that some tables list for safe current capacity and not necessarily for code compliant or for the voltage level where you are working. Take a look at the rating for 12AWG and see if they say about 20 amps. If so, you have the right table. Make it a little thicker (smaller AWG number) for lower voltage battery runs. 10AWG is typical for solar panel strings and 00 or 0000AWG are typically used for batteries on big systems.

It isn’t just the ampacity or wire gauge that is important. Use wire rated for the application. Here, someone used 10AWG THHN wire instead of approved solar cable to wire panels. 6 years later, the outer insulation layer is peeling off. Another few years and there could be some serious problems! Use the THHN in conduit to power your central air!

As for my situation, to dig or not to dig? One of these days. Maybe.

Various and Sundry Items

I have not forgotten you. I’ve been upgrading my own system, while hot rodding one of my solar powered electric farm vehicles, getting Turbo Beast stuck on archæology expeditions, cleaning up hurricane debris and goofing off when possible. I have another kilowatt of solar connected and 1500 watts more waiting for a mounting rack. The 12kw inverter set is connected to the transfer switch to the house, leaving the old inverter on standby. The new batteries are working out well.

One of my electric farm trucks is based on a Yamaha G19 golf car. For the record, it is CAR, not CART. Legal definition. Honest. Anyway, the little truck has always been a little low and has been prone to getting sticks jammed under it if you run over them. We normally have plenty of sticks, but with last summer’s hurricanes we have an overabundance of them, not to mention fallen trees by the hundreds. I don’t run over sticks, but unnamed others do. This rips all the wires out of the bottom and the vehicle is no longer useful. The wiring is peculiar in golf cars and most of it has to be intact for it to run.

After the last stranding, I ordered a lift kit to get the bottom out of the sticks. Then I needed 23″ Mud Crushers on 10″ mag wheels. Sticks don’t bother it, now. Mud, either. It is fitted with a new 3000 watt pure sine inverter, so I can run the big electric chainsaw and all of the woodworking tools. I’ve had it with gas saws and sorry gas. So I am doing some cleanup logging with the Yamaha, cutting sawmill size stuff and firewood. Oh, the car got some heavier springs so I can carry 1000 lbs of firewood. It will be getting a new body and revised truck bed, as well.

You’d be surprised what you can do with a small electric work horse like this. It is great for shuttling trailers, hauling firewood, providing power to remote places and just having fun. All the local donkeys, Fred, Molly and Hector, recognize it and come to their fences to beg carrots as we go by. Best of all, I plug these contraptions into the solar and I don’t have to worry about sour “gasoline” causing valves to stick and pushrods to bend, like on my mower fleet. In fact, I’m trading for an EZGO, tomorrow, so that will eventually bring the electric fleet to 3. A friend got it and wanted to convert it to gas and I had a gasser I wanted to run electric, so we are swapping.

Without the lift and heavy springs, the little Yamaha would carry a good load during hurricane cleanup.
Neal and Gracie go foraging for firewood in the electric jalopy. Since this 2018 pic, it got a windshield and revised truck bed. The jalopy is not bothered by sticks and goes fast, but it does not have Mud Crushers and mag wheels.

I can plug these directly into the 48v solar power system or I can plug them into a charger from the 120vac. Think about, though, a full size electric car or pickup. All the manufacturers are proclaiming a date by which they will stop making gas cars. Where is all of this power going to come from? I just saw the specs for the new electric MINI, which is small in capacity. A 120 plug in will charge at 2%, or a bit over 2 days to charge the thing from empty. A Tesla or Rivian might take a week, but at that rate you probably would not over tax a typical home solar system. I think the total rush to all electric cars is going to cause some new problems. AND opportunities.

The future of grid tie solar is looking really iffy. Some power companies offer net metering and that makes grid tie a good investment. Some companies started with grid tie or pretty good deals and changed the deal after everybody made the investment. The latest dirty deed is a proposal–it hasn’t happened yet– to allow grid tie, but you have to pay a $90 monthly service charge. 3 companies, at least, in California are pushing this and California has mandatory solar required on new houses. That would guarantee the power company a minimum power bill of $90 a month whether you used any or not. Never fear, hybrid and Zero Export Grid Tie are here! I’ve discussed these before and will do so again. Of course, you can always go off grid! Are the power companies facing an exodus of customers? Well, look at how many ships are registered where they don’t have high fees. Look at high tax states that are losing citizens to lower tax states like Texas and Florida. The power companies might find that they are no longer needed!

Now if you were looking for some nitty gritty solar how-to, that is coming soon. We’ve been gathering details of a system Bruce in PA (I think that’s really his name) built some years back. It has some special considerations with high pitched roof and snow loads.

Sometimes the snow is too thick to even see the panels at Bruce’s house!

It looks like I will be recommissioning a system I shut down last year after the owner died. The new owner wants it running, but we are going to have to get creative to make it work on his battery budget. We’ll discuss some of the requirements and options.

And on my own project, the price of the copper cable to get the higher output to the house has soared 50% to over $900 in the past two weeks. We’ll discuss ampacity and various wire choices for tightwads, like me. Stay tuned.

As far as Turbo Beast and archæology go, I’m using lidar topography mapping to take a new look at a mill survey I helped with back in the 90s. Growing up I never knew we had water-powered mills in flat Florida, but there were loads of them, dating back to the 1700s. And I am on the hunt for old cemeteries. The loggers are chewing them up and they are being lost. Many of the mills and graveyards are related and well beyond the asphalt. Dodge’s version of Positraction simply isn’t very good, though, and I got stuck twice on the last outing. My Chevy is much better, but it is not equipped with Mud Crushers. I’ve backed the 4wd Nissan D21 out of the barn and it may return to service. Just what I need…another tag and more insurance. At least my fedora and boots are in good shape and ready for service in the field. –Neal

Baby, It’s Cold Outside

(I wrote this in December and somehow it did not get posted until April!)

This morning it was about 50 degrees. Tomorrow morning we are expecting 28. The constant temperature swings make it difficult to dress. Layering is the key.

Temperature changes affect your solar power system, too, particularly in battery charging. Is there any action you need to take? Depends.

Lead acid batteries, sealed or flooded, need a higher charge voltage in cold weather. If your charge controller or inverter/charger has a temperature sensor that sticks or bolts to your battery, you’re maybe ok. And when I say battery, I mean the total pile of cells, not just one casing holding one or more cells. Ideally, they are all behaving the same and have about the same temperature. You won’t have a sensor for each one. It doesn’t hurt to spot check them all with an infrared thermometer once in a while to be sure.

Only one of my many charge controllers has temperature compensation, so I have to do a little manual intervention as the weather changes. It takes a while for tons of lead to cool down. Longer if you have an insulated battery box or cabinet. I don’t.

I go out to my Man Cave/Control Room most evenings to watch movies, read or work on projects, so I keep up with the meters. Lately they have been running a little low. I have a temperature chart for my batteries and it shows my settings are a little low. I just bumped up the charge voltage to 59.9 volts for the highest setting, maintaining the float at 54.4. At some point, my inverter complains of too much voltage, so I go with the minimum settings. I can hear the golf car batteries sizzling in the jalopy in the afternoon, but the main bank is holding higher at night, keeping my hand away from the grid switch.

It is a delicate balancing act. If I boil the AGM bank I will kill them. If I run them too low, I shorten their lives. If I switch to the grid, what’s the point in having solar?

The system is getting an upgrade. I recently acquired my own mobile solar generator trailer, similar to the one in the Turbo Beast blog. It has been interesting to explore its wonders and integrating its components into my home system will be a big upgrade. The mobile system has a Midnite Solar MPPT charge controller, a pretty nice charger, but the real star and boss of operations is a pair of 6048 Sunny Island inverters.

It appears that all charging runs through the SI pair. It keeps up with State of Charge and controls an automatic diesel generator. The other night I forced the battery down with heavy loads. The generator started and before it was over the battery voltage had soared to 62 volts! A previous run had gone to 60.8 volts. The difference was the temperature. These are flooded forklift batteries on the trailer and have different needs than the AGMs in the Solar Shed. I will have to change the settings when the Sunny Islands and the Kubota genset are attached to the Shed, but then it will all be automatic.

I do not offer any settings or charts for you, here, because batteries are not all the same. These days you can find detailed data sheets online for most batteries. If you can’t find one for your particular battery, try another brand of similar type. For example, a generic golf car battery like the Sun 230 has specs similar to a Trojan T105 or Energizer GC2. My big AGMs were marketed for standby use and had no specs for cyclical use, so I had to borrow data from another brand.

I do not recommend mixing battery types, but I do it myself. I am evaluating a big pile of AGMs for the Solar Yacht project, I have flooded batteries in my electric farm vehicles and, soon, I will add the 2 tons of forklift batteries from the mobile unit. In this case, the AGMs are the fussiest and most expensive, so I will go with their settings and pull the flooded batteries off to the side from time to time to give them a desulphating charge that would kill the AGMs.

If you put your own system together you should know if you have temperature compensation built in. If not, ask your installer or do a little snooping. A temperature sensor cable usually plugs in or screws to a terminal block marked something like “temp.” All that I have seen have used a thin round wire or flat cable, similar to “modular” cable used on real telephones. Remember those? At the battery end the sensor will be embedded in a piece of plastic that sticks to the battery or in a ring terminal that connects with the battery cable.

Yes, the shorter days and winter gloom could be hurting the performance of your system, but it could also be something as easy to change as a charge setting. When in doubt, read the manual!–Neal

What’s a Shunt?

Let’s talk about shunts.

That thing in the picture is a shunt.  As in when your Momma said, “Y’all shunt be pokin’ that possum ’cause he’ll bite you!”? No, not that kind of shunt.  For the record, my Mom was born in Massachusetts and raised in Palm Beach County, Florida, with a Danish father and a Down East mother, so she never did learn to speak proper Southern.

A shunt is actually just a resistor.  It’s a very LOW resistance that can handle a relatively large current…some times a sho’nuff large current.  (Southern is my native language.)  Of particular note, a standalone shunt, like this one, has 4 connections. The two big ones carry the current and the two little ones are for the meter.

They come in all sizes. I found this one in my attic good for 100 amps.

So of what use is it?  Glad you asked!  If you are going to be working with lots of DC (Direct Current) power, it is often a good idea to know how much is flowing and which way.  Is it coming or going?  Shunt’s work with AC, too, but mostly AC has another neat gadget that is easier to use.

Typical uses in solar would be to see how much current is going into your inverter or how much current is being produced by your solar panels.  Let’s say you want to monitor your batteries.  The shunt is placed in line with your big battery cable, like a fuse you probably should have.  Properly sized, it should just sit there and not bother
anything.  Because the resistance is very, very low, there will not be much voltage drop across it, but there will be just a teeny bit.  The shunt’s data sheet will tell you just how much voltage drop or sometime the amount will be stamped somewhere near the terminals.

For every 2 amps through this shunt you will get 1 millivolt. Calibrate your meter scale accordingly

Let’s say you have a shunt that drops 150 millivolts (thousandths of a volt) when passing through 150 amps.  When you connect a meter that reads millivolts to the smaller terminals, then the meter will display your current flow in amps.  (It is really amperes, but nobody says that.)  If you have the old fashion d’Arsonval mechanical meter, the needle will swing to the right or left of center, indicating that the battery bank is being charged or discharged.  Your digital meter will add a “-” indicator for discharge.

Sometimes shunts are built into equipment and you won’t see them.  In fact, the built in shunts are often just a fat wire jumper on a circuit board, because, remember, a shunt is just a very low resistance.  Any charge controller that displays current will have one.

Let’s take a look at Ohm’s Law, for a moment.  I know some of you will glaze over at the thought of math, but if I can do it, you can do it.  The hard part is the goofy labels.  E=I x R.  If it helps, make it V=A x R because in this variation of it, we are saying the Voltage = the Amps x Resistance.  You can turn it around and say I x R=E.  If our shunt has a resistance of .001 Ohms (the electronic symbol for this is a Greek letter that looks a bit like an upside down horseshoe.) and we put 45 amps through it, then 45 x .001=.045 volts or 45 millivolts.

Was that so hard?

Most of the shunts in my system are built into the magic boxes, but the Sunny Island inverters are connected through some external shunts hidden behind a cover plate.  (A cover plate is a good idea because you may have noticed that touching active electrical components can be unpleasant or even hazardous to your well being.)  I bought the cabinet
pre-wired, but it appears it is using the shunts for battery management.  The Sunny Island is a wonderful box, but very complex in its abilities.  In my system, it not only monitors current flow when using power from the batteries, but it manages the charging of the batteries from an external source, like the grid or my Diesel generator, which is also controlled by the Sunny Island.  Charging and equalizing batteries is a very complex business if you want the batteries to last a long time and the Sunny Island uses the shunts to regulate how much current is flowing based on the size of the battery, temperature and the state of charge.

This image has an empty alt attribute; its file name is 20210403_123026-Medium-rotated.jpg
They put this shunt where you’d have a hard time getting your fingers to it. Or your camera. The big wires are carrying the current and the small red and black wires go to the metering circuit. Polarity counts! I’m not sure I approve of the solid conductor signal wire.

So you see, monitoring current flow provides useful information and a shunt makes it easy. Even easier, for under $20 you can buy a kit with digital meter and matching shunt on Ebay.–Neal

Stephen is Thinking Solar

And 2000 pound monsters.

I got this comment from Stephen. I’ll let you take a look at it and then I’ll comment, OK?

“Well I’m a new-b, & an old fart, I wanted to start this process a long time ago, but for the dollars…
I’m interested in learning more of the availability of these 2000lb. Monsters, though I really need some education on the basics like …If I Install 11,500 watts of panels on my clear view roof, do I need to buy ( 3) 4048 inverters & then split the panels over 3 separate systems?? Sometime in the future I may purchase a nice 20kw diesel standby gen. w/ ags. Probably will take a while $$$again.”

OK, here we go. No worries about being new. Every day is a new day with solar. Every morning I read a half dozen or more solar and energy newsletters and there is always something new. As far as being an old fart goes, Old Guys Rule! Step away from the rocking chair! And as far as the $$$ go, you are already ahead of the game if you’ve found Sun Electronics. I look at some of the pro systems going in around me and OMG the prices! My system will blow most of them away at a fraction of the cost.

Now, you ask about “2000 lb. Monsters”. I assume you are talking about my forklift batteries. 540ah at 48v is a good start and I figure 4 of them will put you in good shape. However, there’s that 2000 lb. bit to consider. The more modular battery systems are easier to handle and many require little or no maintenance. The forklift batteries can be a super deal, though. Probably the best ones are coming off a 2 year lift truck lease. For some reason, these leasing companies pull the 2 year batteries and install new. You can find these on Ebay. There are forklift companies and battery companies in most cities and they can be a source. It could be good to buy locally and cultivate a relationship because your battery may need service some day. THEY can change a cell or rejuvenate a tired battery, but I don’t think they do house calls. Maybe, though. There is a funny numbering system for these monsters that tells you the volts and amp hour ratings, but you have to know the code. And since we are talking about batteries, I assume we are not talking about grid tie.

Dragging 2000 pound monsters on a sled is not so hard. Scooting them against the wall and onto a pallet with a jack and a pry bar is when it gets fun. Old Guys Rule!

Grid tie can be quickest and cheapest to install, but most folks like having their lights stay on when the grid goes down? I hear that happens. You can still have the grid and run it in with the solar in a hybrid, interactive system so you can avoid fees and all manner of unpleasantries that some power companies impose.

I’m not sure how, but somehow you came to the conclusion that you want 11,500 watts of solar panels on your roof. That’s actually a pretty good number for a typical American home. That’s over 200 amps of current in a 48 volt system, so you need a pretty hefty battery bank to soak it all up without causing problems. You note you have a clear view from your roof….to the south? That’s great for maximum production, but we are finding that it is actually pretty good to have some panels facing the west. I know my a/c is running in earnest late in the afternoon and the sun is toward the west at that time. After success with a small experiment, I am putting in a 10 panel array in a westerly orientation. North is not a good direction, but pretty much everything else will work.

Next you mention 3-4048 inverters and I am not sure why. Because 3 x 4048 adds up to pretty close to that 11,500 watts of solar? That isn’t how it works. Your modules are going to connect in blocks of, say, 3. Those blocks meet up in Combiner Boxes, as appropriate, and all that combined electrical goodness goes into a charge controller. Most of these charge controllers I use have an input of 130-160 vdc. 3 panels in series, generally add up to that. There are exceptions, so check the data sheets and think ahead. I also have a 250v input charge controller that will handle 5 x 60 cell modules or 4 of the higher voltage 72 cell modules. In addition to those volts, you need to keep up with the watts, as well. A 60 amp charge controller is good for around 3000 watts. I say “around” because folks have different takes on how mathematics works. In my motley collection, the 60 amp controllers range from 2800 to 3200 watts. Some are more tolerant than others to the occasional aberration. Read the data sheet, watching for gotchas.

There are bigger charge controllers, like the FM300, but I kind of like the idea of having a little redundancy. I have 6 charge controllers on the main system, but 4 would be plenty. By now you have guessed that if you are using 3000 watt charge controllers, YOU will need 4 of them to cover all those watts flowing off the roof. Now, do as I say and not as I do, here…my system didn’t just happen, it evolved. I have several varieties of charge controllers, so they can’t share a communications system if you like to chuckle over charts and graphs of power production.

Now we have all of those solar watts tamed and being shoveled into our monster battery pack. Let me tell you about a fellow who fed a similar amount of power into a not-quite-monstrous battery pack of 400 ah. First, that was not enough to do much good on a whole house system. Second, cramming 200 amps into a small battery pack is just going to cook the batteries. He had some nice AGM batteries, but not for very long. 60 amps for the set should have been the limit. I have some AGM batteries of twice the size and the data sheet says don’t exceed a charge rate of 40 amps. I have 4 strings of those and the monsters and two electric vehicles to soak up well over 200 amps without exceeding the limit on the charging rate of the delicate AGMs.

Better still, a forklift battery or any other variety of flooded lead acid or FLA battery is pretty tolerant of a hard charge, though you might have to water more frequently.

OKAY, back to the 4048 inverters. You apparently broke the code, here. 40=4000 watts and 48=48 volts. Why 3? What you need to consider for inverters is how much do you need? Being careful, I have run everything but the electric stove and clothes dryer, including one of the central a/c units with a 5048. I don’t have an electric water heater. At the present 10,000 watts I could pretty much run it all if I had a heavy enough cable. (That’s a project for another day) My old partner, Tom, did well with a 12kw inverter. Then it broke and he ran, I think, an 8kw, one of those nice Outback GS units that Roberto has. It was not quite enough, but you can run two of them in parallel for 16kw, so he was in good shape and if one failed he could get by while repairs were being made.

There are myriad features in today’s hardware. Many 4048 inverters I have seen, like the old Xantrex or Trace or Sunny Island are 120 only. You connect two with a combiner to make 120/240 for normal household operation. I am presently cabling in a pair of Sunny Island 6048 units that work the same way. You gotta have two of them and 3 would be just weird. The combined 12kw would be overkill for me. Right now I use them for welding, so they are pretty tough. My homebuilt 10k48 puts out 110/220 on its own, but has no tricks. The Outback GS8048 makes 110/220 standalone and you can stack it to double the power. It can also do lots of nice tricks, like hybrid, grid tie or automatic transfer. The beauty of the 8048 over the smaller size is that you get twice the power for just a grand more.

Now what? How are we going to do this? I’ve mentioned some really versatile gear, so we have options. If you want to go off grid, you are good to go. If you want to keep the grid for backup or because you use a lot of power, how about a hybrid setup? This is especially handy if your power company hates solar (charges fees and makes onerous rules). The aforementioned Tom connected his inverter to the house through a transfer switch, like he used with his generator. The grid had a separate line down to the barn where it entered the secondary input of the inverter. During the day, and as long as his batteries were above the threshold he set, the inverter provided power to the house. On warm summer nights, the a/c would draw down the battery and the system would shift back to grid. There were no extra fees and no selling electricity to the power company for 3 cents and then buying it back at night for 13. His big limitation was his tiny battery bank. With 2000 amp hours, I suspect a changeover to grid would have been rare.

I have simplified things here, of course. You’ll need to throw in some surge protectors and circuit breakers. There are the mounting racks for the panels and the cables and gadgets to comply with the new “rapid shutdown” rules to let the fireman shut down the panels before spraying water on the roof, in case of fire.

Finally, a 20kw generator? Diesel is a great choice. Today’s gasoline just won’t keep. There are natural gas and propane units that may be a good choice, too, but I am a fan of diesel. I normally keep enough diesel and jet fuel around that I could run a generator for a year. Many years ago when we had a 5 week outage I had an old 15kw diesel that ran at 1200 rpm. It was meant to run continuously and had 3 phase. I brought 2 legs in through one of the external a/c disconnect boxes and ran the whole house. It came in through a 30 amp breaker, so I could only use around 7000 watts and we did fine. It would charge my battery backup, run the stove, laundry and water heater while I was getting ready for work and then we’d shut it down. (This was back when I was willing to work for a living.) Lights and fridge and such ran off the battery backup except during breakfast and supper.

So I guess the point is that 20kw is probably more than you need. My recent generator addition is an 11kw Kubota LoBoy with 113 gallon fuel tank and autostart. I can’t imagine needing more than that. Oh, and by the way, the smart inverter is taking that power and passing it to the house and/or charging the battery as needed. Boy, these inverters are smart, but the manual will blow your mind. You actually have to think, which I suppose is usually the best plan.

Did I cover it all? Get busy, Stephen!

-Neal

Does Anybody Have a Fire Extinguisher?

It is only natural to want to improve or hot rod your system. Know the limits, though.

Despite all the political controversy, Facebook remains a useful tool, especially the “groups” if you are into a special interest. I don’t have a FB account, but I hijacked my wife’s account to join a group of folks who also have the mobile solar generators, like the one I bought. (See TurboBeast story).

There is a wealth of information to be shared on such a complex combination of mechanics and electronics. Some people are very knowledgeable and some are total newbies. There’s lots of sharing and lots of creativity.

Let’s examine the system. There are 10 solar modules, 60 cell units from 230 to 270 watts, depending on build date. They are arranged in two strings of 5, meeting in a MidNite Solar (MS) combiner box and brought under control by a MS250 charge controller. The MS250 charges 4000 lbs. of forklift batteries, which may be flat plate or the newer tubular plate flooded lead acid batteries. The batteries supply a pair of Sunny Island 6048 inverters, which combine to output 12kw of 110/220 power. The Sunny also controls my autostart diesel generator, so I’ll have to try really hard to run down those batteries.

The 12kw output will easily supply most houses, I think. I’ve seen houses run on less. The weakness in using these rigs to run a house, though, is that they have only 2500 watts of solar and around 1000 ah of battery. 2000+ ah is working great for me. I have found the hard way that the recently revised recommendations for battery sizing are much more practical than the older assumptions. And more expensive, of course.

The 2500 watt solar limitation is pretty much a physical limitation. There are just so many panels you can mount on a 17′ trailer bed. Yet, since these were built, panel output has increased.

Courtney, for example, after consulting with me, replaced his panels with 60 cell 320 watt panels. That’s a 700 watt boost and he stayed safe.

The MidNite Solar charge controllers rate things a little differently than some others. Many show the output CURRENT in their names, like an Outback FlexMax 60 is rated for 60 amps or a FM-80 is rated for 80 amps. If you want to power the world, I think there is even a FM-300! But the MS250 is talking about volts, when it puts a number in the name. Whereas the FM is rated around 150v, if I remember right, the MS is rated at 250v. The difference affects how many modules and what kind of modules you can put in a series string.

With a 150 v limit, you’ll find that 3 typical 60 or 72 cell panels in series is a good way to go. They each have a peak output of around 36 or 46 volts, but always consult the data sheet or the label on the back of the module. On the Sunelect.com website you’ll usually find a datasheet download available. Yes, consult the sheet. I have bought some modules from Roberto that had 90 volt output. I just run those in parallel on a 150v charge controller.

With the MS250 controller, you can easily run a string of 5 60 cell modules, as long as you stay with in the power rating of the controller and the 320 watt modules do this. Then one of the guys, Mike, comes up with this: “I bought one with the panels swapped out for 72 cell, 370 watt panels. Nothing has burned up yet, but it has problems. The Midnite is in “hypervoc” mode most of the time, and screams like a banshee. I wouldn’t recommend it.” Mike lives life on the edge.

The problem is that he has exceeded both the voltage and current ratings of his MS250 charge controller. That it is still running is a testament to robust design, but I suspect that controller will live hard, die young and leave a charred corpse. Which reminds me, do you have a fire extinguisher around your system? Mike admits that his charge controller is literally hollering about its working conditions. The proper way of doing this upgrade would be to add an additional charge controller. He’s about to buy a new one, anyway! Or two, if he wants to put it right.

Dale had another solution: Leave off two of the panels, which would defeat the upgrade, “Or, wire the two left off panels in series, straight to the battery? What could go wrong overcharge the battery if there’s not much load on the system, but otherwise maybe ok. One 72 cell panel wouldn’t be high enough voltage to charge the battery”

OMG, NO-OOOO! It might actually work, but if you left it unattended for a while you could boil out the batteies, which I think run around $5-6000 EACH. You’d also miss out on that MPPT goodness that a quality charge controller can provide.

I guess what this comes down to is think creatively, share ideas with others, ReadTFManual, and keep a fire extinguisher handy.

–Neal

Batteries–Bigger is Better

Sometimes bigger really is better.

It is raining, today. What to do? I’m in the middle of a huge upgrade of my solar power system, but most of the work will be outside and I don’t care to get wet. Wet, as in a hot tub is ok. Being cold and wet does not appeal to me.

I guess I can water batteries. It is time for some of them. In my various independent and blended systems I have a lot of cells that are AGM and don’t require water. I also have 168 cells that do need to be watered. This is nuts, but it is just the sort of thing that can happen if you start small and gradually grow the system. Things can get out of hand.

I recently acquired a couple of forklift batteries in the Mobile Solar Generator trailer I bought and I am impressed. Mine had been serviced, but another set belonging to a friend had not…for over 4 years. They still had water above the plates. Granted, we had to add 12 gallons to top up, but if they can go 4 years without being damaged, getting overlooked for a month will never be a problem. In fact, these are designed to be checked every 3 months in heavy service.

Not pretty, but that’s 50+ KWH of storage and they only need to be watered 4 times a year.

I started off with so-called golf car batteries. Exide calls them electric vehicle batteries, which I like as a better term. Many people refer to GC batteries as “starter” batteries. Not in the sense that they are used for starting a vehicle. More like in the sense of training wheels on your kid’s bike. I resent that term, but I suppose it is true.

That’s a bunch of cells to water for 450 amp-hours

Many people use GC batteries, like the Sun230 that Sun Electronics sells. That’s all they need or that’s all they can afford. The difference between a Sun230 and a Trojan T105 or an Eveready or Exide GC2 is basically the price. The Sun230 is cheaper and has a few more amp hours. Also, you buy them from Sun Electronics, you pay no tax and need no core. Florida exempts solar stuff, but try telling Sam’s Club or WalMart that. Starter batteries? Fine. You gotta start somewhere.

If you have a big budget, then by all means think big. It can save you in the long run. That’s the big holdup on solar, though, isn’t it? You can get electricity from the PoCo for $250 per month, whereas the sun’s free electricity might cost you $15,000 or $50,000 more up front, unless you do-it-yourself. I heard from a guy the other day with a $350 power bill and a quote for a $130,000 power system. I understand why folks start small. I started small, actually intending the system as a test bed for stuff I was doing with my solar boats. It just got out of hand, after a while.

So what’s the difference with the bigger batteries? For years, the L16 was the battery you aspired to have. Some scrounged them from floor scrubbers and some bought retail. Comparing to a GC2, the L16 is a lot more expensive in $/amp hour. They may be cheaper in the long run, though, because they have thicker plates and hold more acid. Thicker plates generally equate to longer life and more liquid means you are less likely to get low and ruin the thing.

My first visit to Sun’s old Miami warehouse was a hoot. Oh, the new store is nicer, but I don’t think it has the character of the old place, especially when the grafitti artists had been at work. In the showroom there were these huge Rolls batteries. Actually, they were hollow demo dummies, but huge all the same. Just 2 volts, but lots of lead, acid and amp hours if you got the real thing. A hand truck is required to move them, the real ones, not like the featherweight 64 pounds of a GC2. Put 24 of them together to make 48 volts and you had serious storage and longer life. Also, you only had 24 cells to water, as opposed to scads of them for the same power in a stack of GC2s.

This is a 2v cell in what appears to be a semi-portable L16 package.

The big 2 volt scheme is pretty good, I think. They are still hand truck portable, yet retain the advantages of scale. My new batteries are 510 ah at 48v (8 hr. rate) and weigh a ton each. It’s like a set of the semi-portable Rolls cells soldered together in a steel box. Actually, though they are new to me, they are 5 years old, which in big battery life is just broken in good. They are not very portable, though. My big tractor might lift them, but it is out of order. The smaller tractor will not. Getting them off the trailer was easy enough with a chain fall and an oak limb. I used old tech and sledded them to the Solar Shed. There is not much room to maneuver behind the shed, so the wimpy tractor is little help. Jacks and cleverness prevailed, though.

If you can’t pick them up, you can sled them. With a farm jack you can nudge them over. If working on concrete, slip a couple of pieces of pipe under the and roll them across the floor.

At my friend’s house, he has stripped 2 of the solar trailers. He has a better infrastructure setup. He offloaded with an I-beam and trolley setup, then used pipe rollers to move the batteries through the garage. He is starting with 2160 amp hours of battery in his new system. That is super for a house his size. At a ton each, the batteries are still moderately portable, given his circumstances. I hope the garage doesn’t settle on one side and tip over.

There are 2 big, gray batteries in the middle of the trailer, 2000lbs each. If it takes this much gear to move 2 batteries, you might want to consider smaller units. BUT, some people just like to have the toys to do this!

In Texas, where everything is bigger, one of our correspondents shared photos of his 800+ ah Bulldog battery (if I remember right). Now that was one big battery and he has a forklift and a trolley to move it.

I’m starting to ramble, I suppose, but the point is, the more battery you have the better your system will perform and the longer the batteries will last. If you use large batteries, instead of lots of little batteries, they are likely to last longer and require a lot less maintenance.

As for my upgrade, with over 2000 amp hours of storage I am easily rolling through multiple cloudy days without hitting the dreaded 50% depth of discharge. 10 more solar modules are waiting to squeeze a few more watts out of the clouds, too, but the huge reserve seems to have solved a lot of issues. I have also added an automatic diesel generator, just in case, but so far it has only had monthly exercise run time.

–Neal

I’m Declaring a Holiday

Hmmm, I guess it already is a holiday, today, Presidents Day, but tomorrow is a good day, too.

Some might think I have been on a long holiday, already, but the hiatus has been a combination of clunky WordPress blogging platform and sharing my internet tower with school kids and work-at-homes. I have been to the peak of my hurricane-battered roof and moved my antenna higher and rotated it to a different tower. This has resulted in improved internet speeds, except when it rains. It rains for all of February.

Back to my holiday, Black Ice Day. Today’s storms will transition to 20 degrees in the morning, with perhaps a little “wintry mix” or snow overnight and frozen roads to start the work day. And this is FLORIDA, for crying out loud!

Checking with contacts around the country, Paul is near Houston. It is 18 degrees at noon and the power is out. Somebody said the windmills froze. He does not have backup power. He does have a fireplace. Bundle up, buddy.

A Texas Covid vax storage site lost power and backup failed, causing a mad rush to use the stuff up before it spoiled.

I have not heard from Daryl out in Texas for a while. I suspect he will be fine. His solar and battery backup system is awesome.

If that does not count as awesome, what does?

Bruce is in Pennsylvania and pretty much stays snowed under. He says they would welcome Global Warming to visit his state, this year. He has offered a parking spot at his house. He has solar and a big generator. Good thing. What he really needs is a snowplow for his roof. Bruce is going to give us an overview of his system, soon. Watch for it.

See? Bruce has solar panels. Look a little harder.

Courtney is to the left of Raleigh. Yesterday he told me the grid had just come back on after a two day break owing to ice. Courtney bought several of those mobile solar generator trailers I told you about in the Turbo Beast adventure. He has been stripping his down for components to build a world class backyard system. The problem is, it is not wired up. Luckily, he had one trailer left intact and he plugged that into the house. Under gray skies, the solar didn’t handle it all, but the automatic generator kicked on a couple of times to top up the battery bank and life was good at Casa Courtney. I hope he didn’t leave the porch light on all night to taunt the neighbors. That would just be mean.

Courtney rode out the ice storm with one of these.

My neighbor Brad finally got the ok from our 3rd world power co-op to turn on his solar power system. I don’t think he’s worried about ice taking out the grid.

That’s 27 kw on the garage roof and there are 3 Powerwall batteries on the side of the house.

And me? Think I’m worried? I recently added another 1100 ah of battery and an automatic diesel backup generator to what I already had. There’s a stack of 10 panels I’ll be adding to the array when I get to it.

Under the 11kw Diesel generator is a 113 gallon fuel tank. The gray blob to the left is 1100ah of 48v forklift batteries. There wasn’t enough room in the Man Cave. I am gathering material for an awning.

And where John Kimball and Sun Electronics are based in Miami, it is a bone-chilling 81 degrees. And sunny. Hardly seems fair. He has a warehouse full of solar and backup power gear, but it doesn’t seem like he needs it this week.

Maybe by now you’ve gotten the idea that it might be a good idea to have some power backup. It is. Some of the examples presented here have been a bit pricey, but it does not have to be. It comes down to budget and level of comfort that you require. We get a little spoiled here in the USA.

I was perusing the ‘net for some info on tubular batteries one day and came across an entry in a forum: “I have two lights and a fan…” Wait a minute! I was thinking tubular batteries were all the 2000 pound monsters I have, but apparently there are small ones, too. This guy was not talking about small power for a camper or boat. This was power for his house in India! 2 lights and a fan powered by a solar panel and a battery was probably a real mind blower to his neighbors.

How hard can 2 lights and a fan be? Thanks to the SunElec graphics department for this illustration.

If he can get by every day with that, you might find it very helpful for a few days when the grid is down. Of course, you’ll want more. No gas stove? Coleman and others offer a one burner butane stove to fix your dinner. It costs $20 at any place that sells camping gear. You may already have a grill and that works, too, but don’t bring it indoors. The fridge? Oh, come on! It’s snowing! Well, during the warm months, after a hurricane, I have connected an appropriately-sized inverter to my car and powered the fridge intermittently to keep the foods from changing colors. The bigger inverter in the car can also run the microwave or Mr. Coffee.

Once you get a little power backup you can build on it. Last summer I was in the doghouse, having spent a bunch of money on bigger, fresher batteries, but then we had a week without the grid after a ‘cane. Suddenly it was all ok and there were no complaints when I bought more! Sooner or later you will need backup and I guarantee that if you are the only one to keep the lights in the neighborhood, you will be a hero in your house. Call Roberto at Sun Electronics and he can fix you up for a price that won’t make you cry.

Please don’t leave the porch light on all night during the outage. That would just be mean.

–Neal

Solar Security

Some people go with solar power to provide energy security to their home or business, especially in areas with a crumbling power grid. But what about the physical security of your solar equipment?

I have given a little thought to protecting my solar investment, but it does a lot to protect itself. For example, the main batteries weight about 250 lbs. each and there are a bunch of them. You’ve gotta be dedicated to haul off those things. The panels are big and bulky. Other things are not. Then there are all the tools and things in the Solar Shed. Much of it is not even behind a door you can lock. On the other hand, common wisdom out here in the country is that if you lock the door a thief will just break it or a window, in addition to stealing your stuff. ‘Tis a quandry.

The reason I am thinking so much about it today is that yesterday I called Stan-the-Hermit, to check on him, just as he was calling me. You’ve seen me writing about him before. He has a cabin way out in the woods and it has been solar powered since the beginning. He also has a house out on the island. He’s been concentrating on that one since the hurricane messed it up and wiped out his truck. He’s been too busy to visit the cabin.

The other day he went to the cabin to get some stuff and discovered he’d been robbed. Being in the woods can prevent people from knowing you are there. Those who know your stuff is there may not touch it, fearing you and a shotgun might be there, too. But Stan wasn’t there and he wasn’t there long enough for someone to figure that out after clearcutting on neighboring land made one of his structures visible from a road. These guys had time to work and they came back day after day.

They got his tools, guns, 2 Honda generators, a trailer, logsplitter….all kinds of stuff, none of which was insured. Then they started picking off pieces of his solar power system. They just cut the wires on the 12v system inverter. They got the 24v inverter, too, and it looks like they just ripped down one of the charge controllers. Too bad they didn’t get ahold of the raw DC string voltage from the solar panels. They didn’t take the batteries or the panels, but they came back while he was there. He gave chase, but they escaped. Hopefully they have decided to quit while they are ahead.

I gave Stan a 2kw inverter for the 12v system, which was otherwise mostly intact. He has lights and power for the TV. They didn’t take the 32″ TV. Probably not big enough. Yeah, he’s sort of back in business, but plenty demoralized. I would be, too.

Thinking about site security I shudder to think about losing all I have built and collected over the years. Then I think about neighbor Brad, who FINALLY got the co-op to sign off on his megabucks system. He has 3 Tesla Powerwall batteries on the side of his house. They are not very heavy and how hard would it be for a thief to make of with them? If I am not mistaken, that’s over $20,000 right there and easy picking. No, I don’t think you have to worry much about having the panels swiped off your roof, but it wouldn’t hurt to lock the barn while the horse is still inside.

I am going to start with a game cam or two in strategic locations and add a DVR video system at the house and shed. They are cheap and pretty easy to install. A DVR should be hidden. It won’t do much good if your thief sees it and hauls it off with your stereo or inverter. Older systems were not very clear, but the last system I put in with a friend was a 1080 HD and that makes ID of faces and license plates a lot easier.

Some game cams can be accessed by smart phone over the cell network, if you don’t have regular Internet service, like me. They blend in to the landscape easily. Ring cameras, and similar products could be great if you do have Internet.

A hail storm, lightning or hurricane is probably the biggest threat to your system. Still, you might want to think a little bit about threats from n’er-do-wells and scoundrels. As for me, I filled the pintle ring of the Mobile Solar Generator trailer in my care with chain and locked it. It’s a start.

–Neal

Neal & Turbo Beast’s Big Solar Adventure

Buying prefabricated mobile solar power plants at auction and quickly spiriting them away.

Read More

It Pays to Know Your Stuff

Some people build their own solar power systems. Some people pick up the phone and then write a check for theirs. It’s ok, either way, but I advise that you at least have a basic understanding of how things work.

If you have to ask why, I can give you a recent example from my neighborhood. It isn’t what a lot of people would call a regular neighborhood. It is nearly a mile to the nearest corner and 4 miles the other way. There are only 7 houses located along the road and nearly twice as many of us live as much as a half mile or more out in the bushes. I don’t think any of us know all of the neighbors. After 30 years here, I’ve gotten to know a few. In fact I think I am in 4th place to become the Old Timer. Miss Christine is 92 and holds that title, for now.

I met the newest neighbor, Brad, last week. I’ve met most of his friends and contractors because a GPS quirk sends them all to my house. That’s how I knew he was getting solar power at his place.

Well, someone who has solar is always interested in keeping up with the Joneses, or the Brads, so I stopped in to meet him the other day when the power lines were down, again.

Oh my! What a system he has. It has some interesting quirks to it, cost a fortune and it doesn’t work!

For some background, Chuck lived there during the last really fun hurricane season, about 15 years ago. The FIVE WEEK power outage prompted Chuck to get a very large propane Generac and a fuel tank to match. Fast forward to 2020, when everything else has gone wrong, and the reported $850/month power bills prompted Brad to add solar.

Now, I don’t know a lot about Brad or his house or his lifestyle, but I suspect that anyone with an $850/ month power bill has a certain amount of potential for conservation measures. Just sayin’.

Back to his system, there are about 27 kilowatts worth of shiny new LG panels on the roof of his 5 car garage/shop structure. It is a great roof for solar, except it faces to the west. I’ve been telling you that solar isn’t just for southern exposure, anymore, but a strictly western exposure is not ideal. On the other hand, the roof of his house is very steep and is full of crazy angles. I’d have to go along with the shop roof placement. BTW, close proximity to a wall of pine trees ruled out putting half of the array on the east face of the shop.

27kw of solar panels are on the 5 car garage and shop. What more could anyone want? I forgot how many of these smaller LG modules there are up there and I’ve lost track every time I’ve tried to count. DC power runs underground to the electronics.

The array is set up for grid tie and that is where the problem lies. I have mentioned more than once that our power co-op hates solar. There are companies, like his installer, that have mastered the power company paperwork and folks like Brad who are willing to put up with the extra fees and unfair billing practices. However, that still does not mean that the power company is any rush to sign off on the connection. (Read some past blogs to find ways around this.)

The thing I don’t like about grid tie is that there has to be a grid to which you tie. On the day of my visit, the grid was down, post Hurricane Zeta, so it hardly mattered that he didn’t have grid tie. Somewhere along the line many solar owners decided that they wanted to keep their lights on when the power company couldn’t. There are several ways to skin that cat and in Brad’s case it was manifested in the form of three Tesla Powerwall batteries.

The Powerwall is a neat gadget, I’ll give them that, but it is pricey. According to a recent article I read, they recently increased the price from $5500 to $7000. Each! It is more than just a battery in a compact box. You have some electronics in there, too. Still, for a fraction of the cost of ONE of those Powerwalls, Roberto can fix you up with the makings of a decent little back up system for your house.

Two Powerwall batteries showing and another around the corner, plus associated hardware. The older looking box is for the Generac generator. All in all, a tidy job.

Back to Brad, though, here he has these batteries and all this stuff ready to go, but his lights were out, too, like most of the other neighbors. All because the power company doesn’t like solar.

Oh, wait, what about that big Generac? Remember, it is still 2020. It was great after Hurricane Sandy. It kept the lights on for a while until the 15 year old propane regulator failed. The inrush of excess gas blew the exhaust system off and the overspeeding motor smoked the control board. He couldn’t get parts before the next storm came.

So now we get to my Know Your Stuff admonition. There is a big gray electrical box with a big red handle in the OFF position. I strongly suspect that moving that handle to the ON position would have turned on the lights. There may have been more to it, but I don’t know Brad’s stuff. Let’s just say that would have worked. That still would not have been a great idea because the system is set up for grid tie. When the power came back on from the co-op, his system would have gone into the forbidden grid-tie mode. His smart power meter would have phoned home and ratted him out and caused more strife with the company that controls the fate of his system.

Let’s look at another scenario. Let’s say that Brad had observed, asked a lot of questions and read all of the manuals. Let’s say that Brad knew his stuff, all that fancy new hardware. He would have known for certain about the big red switch and would have known how to turn off the grid tie mode so the meter couldn’t rat him out. He’d have had solar power for lights, fridge and MR. COFFEE. (A survey of several neighbors, post storm, put powering the coffee machine ahead of keeping the fridge running.)

Brad will eventually get his Generac repaired and the co-op will run out of excuses and sign off on his connection. He’ll have the finest, triple-sourced power system in the area. Life will be good. Take a lesson from Brad’s experience.

Take the time and get to know your stuff. It will be worth the effort. –Neal

I’ll Bet the Neighbors Wish…

When it is raining buckets and the wind is howling, it is very comforting to have the lights stay on when the power lines go down.

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Solar at Florida Governor's Mansion

Where the Politicians Stand

You may have noticed that it is political season. What have the politicians personally done for solar?

Solar at Florida Governor's Mansion
Former Florida Governor Charlie Crist shows off solar panels at the Governor’s Mansion. Hey, it IS the Sunshine State.

Jimmy Carter put solar-thermal panels on the White House roof. They came down the next time the house was reroofed, though they were still working. One is in the Smithsonian and another is in a science museum in China!

Bush 2 put solar on the White House, again, as did Obama. What? Did Obama add some or did Bush’s come down in another roof repair?

Former VP Al Gore, Mr. Global Doom himself, claimed his mansion was carbon neutral because he invested in green energy and bought solar energy credits that added a paltry $432/month to his power bill. He even bought some CF bulbs! To his credit, he has added 33 solar panels since then. I wonder if he has switched to LED bulbs?

What about all those other politicians out there? There is a web site that examines rooftops to find out where they stand. Check out https://solarpowerchallenge.com/ to see where they stand! Use a satellite app to find more rooftops.–Neal

PS–Spoiler. Neither of the presidential candidates appears to have solar power on their personal abodes.

Miscellany

Oh, will they ever come up with the perfect battery? Super capacity? Super cheap? I’ve met one guy who has learned to adjust his pace to make it from Pensacola to Miami in a Tesla. Maybe adopting a more relaxed pace would be good for most folks! Solar Jorge, down in the Keys, likes the discontinued Chevy Volt. You can do your daily commute on electric and charge it with solar, but if you want to run coast-to-coast, there is no problem. In the meantime, let the photo above be a warning. Oh the irony of that bumper sticker and the Honda generator! Sad truth is, the car is probably normally charged by coal generator unless he has his own solar power system.

I am constantly messing with batteries. Adding, upgrading, experimenting, trying to coax a little more life from them. The set of 8 T-105s that I repaired by installing new studs have been added to the battery zero export grid tie system. Most of the house is now off grid, now that the demands for a/c are down and my battery pile is higher. Still, that ZEGT system chips in some sun power when the dryer or oven are running.

When there were no batteries the system was constantly tripping out as the two inverters fought and passing clouds would interrupt the flow. Adding 230 ah of Sun’s house brand batteries helped, but with the high draw of the dryer the inverter would soon trip out at the low end of the battery range. Granted, the trip point was set high for longer life, but adding 220ah of Trojans made a lot of difference. I took a look at the meters this afternoon and each leg was contributing 850 watts. These are “1000” inverters, rated, of course, at 950, actually running at 850. Chinese math. Still, running the dryer with 3300 watts from the utility is better than running it with 5000. The batteries are backed with 2kw of panels and I was registering a real 1750 watts coming out of the charge controller, this afternoon. Not bad. This should be a good setup for summer use when much of the house is on utility power. As is, I could probably drop down to 1 kw of solar.

Here’s a tip. Never throw a cable away and keep a supply of terminals. Old cables became new for minimal cost to lash this together. And remember: Never use 500lbs. of batteries when you can use 1000lbs.!

I had another couple of stray solar batteries. I don’t think Tony and Roberto sell the Outback 106RE batteries anymore, but I had two old ones out of a set of 12 that tested 100% after 5 years of overcharging. What to do? I need to restore the barn solar, so maybe one there to run the lights. It would be nice to have more for tools, but we can always plug into the jalopy for kw power.

And the other? In the wake of the hurricane, my last two running tractors abandoned that classification. One of them decided the fuel injection pump had pumped enough, so I am awaiting parts from Ukraine. BOTH had batteries die, along with the one in the wife’s car. Batteries always seem to start crashing with the first hint of cooler weather! I wondered about the use of an Outback 106RE for starting a Diesel tractor. One way to find out.

In my recent studies of AGM batteries, I learned that while you cannot charge them very hard, they have insane discharge rates. Would a 5 year old abused battery have enough insane discharge to start a Diesel? Yup. I had to change one cable terminal and it worked great. That tells me that surge power to run an inverter should not be much of a problem.

An old solar battery has the tractor running. AGM batteries have tremendous surge capacity, aka “cold cranking amps.” Poor little tractor has to do all the hurricane cleanup.

And speaking of surge power, I was rummaging in the Sunelec.com web site and found an interesting new battery system. It looks awesome, in a neat rolling cabinet. 4 of those would look good in my Man Cave. They are too pretty to put in the battery room. I think the bigger unit, the lithium-based eVault Fortress, can put out around 170 amps, so it would be a good match for one of those GS8048 inverters and around 5kw of solar. It gives both the input and output specs, so it is easy to make sure you are matching the inputs and the outputs. You can stack them for more power.

To replace my current battery pile I would need at least 4 of them. Maybe John will send 4 of them to me for a test drive so I can write a review. I won’t hold my breath!–Neal

Saving a Battery

If a terminal is broken or melted on a battery, you may be able to save it with a simple fix.

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$7 Panel Update

Why not cover a carport with $7 solar panels?

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Aftermath

We take a look at post-hurricane emergency power after Hurricane Sally.

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Torque

I recently had to burrow into the entrails of my new 21 year old truck’s transmission. It is sort of a rite of passage with the old Dodges. Specifications for putting the various pieces back together are very specific. I remember what my little brother did to his Plymouth’s transmission 45 years ago and I didn’t want it to happen on my Dodge, so I bought a new torque wrench. I had one I bought 50 years ago, but it was built for many foot pounds and not the inch pounds required of delicate transmission in the 6000 lb. pickup. The new 1/4″ drive wrench set me back around $20 at America’s favorite Chinese tool store. I didn’t have a coupon.

Having successfully reassembled the transmission, I set out for another load of batteries to evaluate for the Solar Yacht project. Another few hundred amp hours never hurt any battery bank.

These are my biggest batteries yet, but they have the smallest bolts, yet. It uses M6 bolts…less than 1/4″. Most of my others use 5/16. Batteries with just a hole in a post are not terribly worrisome. If you overtighten and break the bolt you just put in another. If you overtighten a top stud battery, like GC batteries, you can pull the stud out, which starts to be a problem. My recent additions have bolts that go into brass inserts in the case. If you break off a bolt you have a real problem. If they are large enough, you might be able to use an extractor. My view of the extractor is that it is a noble thought, but generally not very useful.

The key to not worrying about this stuff at all is to use a torque wrench set to the battery manufacturer’s spec. Do so and the terminal will be tight enough and you won’t break it. I think I set mine to around 80 inch/lbs. for the M6 bolts. Just set the dial and pull on the handle until you feel it click. No worries about too tight or too loose.


I don’t plan to go back into the transmission, anytime soon, so the torque wrench and appropriate sockets will live in the battery room with a few other tools that are commonly needed.–Neal

I Don’t Know What It Is, But I LIKE It!

Every now and then you need to tidy up a bit. I’m bad about that sort of thing. I needed to take a truckload of batteries up to the recycler in Atlanta, but the Chevy just won’t carry enough. Then I inherited, sort of, a Ram 2500, which can carry an additional ton without any problems.

I loaded up and got on the computer to plot a course to the recycler.  The GPS course used the interstate, which is scary to a fellow who has to drive 4 miles to find a stop sign.  Most of the interstate, say between Mobile and Newnan is not scary to me.  But when you get to the outskirts of Atlanta, it just goes crazy.  They don’t have cloverleafs show up on the GPS map, they have spaghetti bowls on display.  I don’t know if their highway designers are geniuses or just plain nuts. 

Using satellite images of the area, I came across the strangest thing.  It was a huge building, though from overhead it looked like an alien vessel, just arrived on our planet.  Better yet, it was festooned with solar panels.

Hey, if you are going to do solar, why not be awesome about it?  I was eventually able to determine that this is the National Archive at Atlanta building.  I spoke with a guy who lived nearby and he was familiar with the building, but he’d never seen an overhead view and nothing on the ground gives a clue.

Georgia has a lot going on with solar.

–Neal

Don’t Be a Post Hurricane Statistic

It makes me mad to see that people die after the storm. You buy a generator to keep the lights and fridge on, but the thing can kill you. Here are some thoughts.

First of all, have a battery backup system in place.  This can be a building block for a future solar power system or it can be a quick solution.  More on that later.

When you buy a generator, also buy a length of stout chain and a padlock.  People steal generators and that is why their owners put them in the garage.  Running a generator in a garage that is attached to the house can lead to carbon monoxide getting into the house and killing you.  Don’t do it.  Chain the thing to a tree or car and let it run outside.

Have lots of fresh gas and oil before the storm.  You won’t be able to buy it for days because the pumps won’t run and neither will the credit card machines.  Store the gas in a safe place in sealed plastic containers.  Any thing not sealed and the gas will go bad quickly and it can ruin your generator.  Bad gas in my 22 hp lawn mower just caused a stuck valve, which pretzeled a push rod.  (See image above) You can’t buy engine parts after your town has blown away.  Treat the gas with Stabil, Sea Foam or Marvel Mystery Oil.

Note, too, that most small generators need the oil changed frequently.  25 hours if it does not have a filter and 50 hours with.  Don’t buy a used generator after a storm…they probably didn’t change the oil.  After you are finished with the generator, let it run out of gas.  That nasty stuff they sell today destroys carburetors.  Change to fresh oil so you are ready for next time.

A whole home natural gas generator is a thing of joy, but expect a whopping gas bill.  Mom spent a bunch on hers and never regretted it.  Her neighborhood got trashed by a tornado a few years back and she was the only one with lights  and a/c for days.

Don’t refuel when the engine is hot.  They can catch fire and blow you up.  And burn down your house if you are doing this in the garage.  You’d think it a simple thing to put the spout in the hole and not spill anything, but a full can is a bit unwieldy at 30 lbs. and those !@#$% worthless government-mandated spouts make it worse.  I broke two of them before I mastered getting the gas out.  You can buy bootleg good spouts, but they cost more than the whole gas can used to cost!

Here’s where your battery backup system can shine.  At night, it is quiet and not making fumes.  You run the generator intermittently at an efficient load to charge the batteries instead of 24/7 buzzing to run light loads.  You will use less fuel. 

Your car can be the generator.  Yeah, your car.  After one storm, I was loathe to drag my monster diesel generator out of the barn.  When I say drag, I mean drag.  It weighs thousands of pounds and is on skids.  Getting it out with a tractor is easy, but putting it back is a pain.  For 3 days, until I knew the power was seriously out and would remain so, I traded generating duties between an F250 and a Chrysler LHS.  There was a 2kw inverter connected to the battery.  I would run them intermittently to keep the fridge cold and a few hours in the evening for lights and TV.

That same storm, my bro had a Rubbermaid tote box full of golf car batteries and an inverter on the balcony of his town house.  His Chevy and a length of SEU service entrance cable topped them up.

I hauled a load of scrounged batteries and an inverter to Mom’s place and connected them to her minivan.

My later Chevy pickup was fitted with a forklift plug on the front so numerous accessories can be used, including a 2kw inverter.  The Dodge Cummins pickup I recently acquired has two huge batteries, huge cables and a huge fuel tank.  I have plans for it.

With just the addition of the inverter, your vehicle can be your power plant.  Better yet, call Roberto at Sun and he can set you up with a simple standalone battery kit or a fully automatic setup that will switch power to the whole house.  Lots of his customers live in places with unstable power, so he has kits for various situations and budgets.  The bigger systems won’t be 12 volts, chargeable by your car, but they will be the first step in a solar power system.

Oh heck, why not go solar?  Or maybe you have.  In the event that the storm might blow away your solar panels, you might consider putting a few under the bed, just for insurance.  We still have some time left in this storm season.  Get prepared.

 

 

 

 

 

 

Fun Fact

This was in the morning newsletter from the American Solar Energy Society.

“A household rooftop solar panel system can reduce pollution by 100 tons of carbon dioxide (CO2) in its lifetime—and this includes the energy it took to manufacture the solar panels. Solar panels can improve future air quality for humans as well as the millions of birds, fish, and mammals that are negatively affected by pollution each year.”

Save the planet! Screw the power company! Go Solar!

–Neal

Still Looking…and Finding

When adding an upgrade to your solar power system, consider what other components may need to be upgraded as well.

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Take A Look Around.

Don't be afraid to look around and borrow ideas from the other guy's system!

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Put an End to Snap, Crackle and Pop

Have you connected a battery, a charge controller or an inverter and had rapidly charging capacitors make a loud pop and maybe even a welding arc that messes up a bolt?

That can be really annoying and it can be dangerous, too. I have never had it blow up a battery but I have had it mess up threads on a battery terminal. The large capacitor bank in my inverter always makes an unnerving POP! Recently, after the inverter suffered a dead short, replacing the fuse made a KABOOM! that could have damaged a finger if it had been in the wrong place. It didn’t do my nerves any good.

As I undertook to test and repair the inverter I was a little gun shy. I didn’t want to blow up a new set of transistors in case they were not the only issues and I did not want to cause further damage to the circuit board. What to do?

Sometimes you just have to stare at a problem and maybe talk it over with your accomplices and acquaintances. One such collaborator is Bruce (in Pa.) (We call him that because he is Bruce and he is in Pennsylvania.) The answer seems to be a precharge resistor and you probably already have one.

I should have thought of this earlier because my golf cars, which control some serious amounts of power–600 amps at 48 V– use them. The precharge resistor can not only take the pop out of connecting capacitive loads, it can warn of impending doom if, say, your inverter has a dead short.

Here’s what I did. I found a light socket and a 40 watt incandescent light bulb, a couple of pieces of wire and some gator clips. If you have an old desk lamp, you can use that, just make sure the bulb is the old-timey one and not a CF or LED. I would go with a bulb in the 20-40 watt range. If I need to start up the inverter after being offline (I just re-installed the repaired 10kw module) I clip the light across the empty fuse holder. The bulb glows briefly as the capacitors charge. Then I can slip in the fuse, snug it down and remove the lamp.

No snap, crackle or pop. If the power module repair had not gone well, the bulb would have continued to glow instead of going dark. We would have eliminated the KABOOM!

That’s a big help from something you might already have in your junk closet.

–Neal

Deconstructing a Solar Power System

A widow has asked me to dismantle her 4 year old 10kw PV system. It isn’t that she didn’t like solar power, but she has to sell the house now and mortgage inspectors are brutally thorough and her husband had overlooked the business of permits when he installed the system. In the process of going through Tom’s system I am finding some things of interest. Here are the good, the bad and the ugly.

First of all, his original installation featured 200 amps of solar power and 180 amps of charge controllers. You should know that a 200 amp solar system will rarely crank out that much, but sometimes it does. You should also know what you have in terms of gear. The first MPPT charge controllers were 60 amp controllers and, by golly, that’d better be all you run through them. One still works. The first one that went bad was replaced with a Flex Max 60. Still a 60 amp controller, but it just limits the output and won’t hurt itself. After the second original charge controller smoked, he finally heeded what I’d told him about underspec’d charge controllers and overdid it, buying two of the FM80 units. That’ll darn sure handle it, but another FM60 would have worked because of the current limiting feature. It may be that he just bought the FM80s and put the FM60 in reserve for the day when the final Brand X controller expires. Anyway, read the manual (RTFM) and sometimes you can save money by not buying too small and sometimes by not buying too large.

Now here is something I like. He made his own cables and with 2 cable ties and a strip of inner tube rubber made what effectively serves as boots. You can still easily get to the bolts, but if you drop a tool, you are less likely to short anything out.

These Trojan T105s are only two years old, but the water was never checked. Ever…until it was observed that the system just wasn’t performing up to snuff. Normally, if you dry out a set of batteries, you get fuming acid toward the end, and even early on you can get some really corroded terminals. Lots of people use Vaseline or ordinary grease on terminals to help with this, but Tom used an anti-corrosion electrical grease, and boy does that stuff work! These terminals are all bare copper and there was not a hint of corrosion on any of the 16 batteries. I don’t have a brand for this, but will be checking on it. No more axle grease for my batteries!

I have harped on keeping the batteries watered on many occasions, but that is not the only battery maintenance you need to do. By the way, when the batteries were topped up with MANY gallons of distilled water, the cells were all active and they regained 50% capacity. That’s says a lot for Trojans. I suspect a good desulphation charge will do wonders for these batteries. Worth a try, anyway. But back to the other battery maintenance chore. You have to snug up the bolts to make sure they stay tight and resistance stays low. What happens when there is resistance? Power is wasted in the form of heat. Fire up the a/c and the dryer and you’ll find out just how much heat. Near the top left of the next photo you can see what a T105 terminal is supposed to look like. Then there are two that were a bit loose.

Neither end of this cable was tight and two batteries ended up with melted terminals. I would recommend that 3 of the batteries in this system not be returned to service because of hot terminal damage. They just can’t be expected to tighten, now. Proceed at own risk.

All of the nuts had washers under them, but none were lock washers. Lock washers serve two purposes, they can keep the nut from backing off, but they also provide a little spring tension. What I like best for batteries is the Belleville washer. This is dished and provides great contact pressure without over-tightening the nuts.

I don’t mean to trash Tom’s system, but it is always good to pay attention to what you should and should not do and observe the results of both. Looking at my photo of a ruined $150 battery is a lot less heartbreaking than have it happen to yours!

It just breaks my heart to turn off a working system! –Neal

Look West Update

I have been observing the performance differences of my west wall array and my conventional south arrays. Arrays still pick up a lot of power under cloudy conditions, but the south arrays are doing better. I think I know why.

The current situation is that the west wall will do pretty well with direct afternoon sunlight. However, it is pretty much facing a dark wall of trees, which reduce diffused and reflected sun from the western sky.

July solar arc at the Solar Shed

On the left of the Solar Shed, the arc of trees between the edge of the airstrip and the red line blocks the view of the sky.

If I cut some trees in that arc, it should brighten up those panels on the wall. The ground falls away very rapidly to the west, so it won’t be very many that have to be cut. Maybe a half dozen are the principal offenders.

It’s too bloody hot to do logging right now and my wood pile is already bloated, so this phase of the project will wait for winter. By then, I should have plenty of “before” data to compare to the “after” data. Stay tuned.

–Neal

What’s with these $7 Solar Panels?

Have you seen the $7 solar modules on the Sun Electronics web site? They are 70 watts, so that’s only a dime apiece for a whole watt! Can they be any good???

I admit it, I am a tightwad and bargain hunter. I didn’t need 50 more solar modules, but I saw where John was advertising these solar panels so cheap and I could not resist. Apparently a lot of people have reservations about these things, because he still has plenty. I’ll tell you the good, bad and ugly bits of my experience and you can make up your own mind if they are for you.

First of all, these are first rate, name brand gear. Google First Solar FS-270 for the spec sheets. Second, they are second hand, having been removed from a school. (why were they removed????) Finally, they are “thin film” modules.

Mostly John sells poly- or mono-crystalline modules. There is somehow a perception among some folks that these are better. However, if you look at pictures of solar farms, you will see an awful lot of these very same thin film modules in use. The pros use them. Here are some general characteristics.

Thin film panels are bigger for a given wattage. Maybe these were taken out of service so they could get more watts from the same amount of space.

Thin film panels work better in cloudy weather. They respond better to the light that is filtered through clouds than the other panels do.

These are rated for 70 watts and have an output of up to 100 volts.

Thin film panels are not as bothered by leaves and bird droppings. In a water monitoring device I used to build, a leaf or a bird splat could cover much of an individual cell on the small panels we used, killing the panel. On the thin film panels, only the amount of area covered by debris was degraded.

Thin film panels are heavier, per watt. The active material is sandwiched between 2 thick sheets of glass.

They are about 2’x4′ in size, making them easy for one person to handle.

Thin film panels can be fragile if not handled properly. Well, I guess that goes for most solar modules, doesn’t it? These have no protective aluminum frame, so there are extra handling and mounting considerations.

Not all of these panels have both MC3 connectors on them. Replacements are cheap, though.

Ok, that’s a bunch of general info. I will now get into a little more detail. I ordered a pallet of 50. That’s the minimum, but you can buy a shipping container full of them, if you need more. That was the easy part. 50 x $7 is $350. Did you ever think you could get 50 modules for that? Just call Roberto or Tony and they can take the order.

Still in stock. This is what they should look like when you get them.

Shipping is where it hurts. If you are in California it is not so bad, but to get them all the way to Florida or anywhere else on the East Coast, it will probably cost more than the panels. For some reason, crossing the Mississippi River costs extra, or it seems that way. I did not have a good experience with this part of it. SAIA was the carrier and they have an unmanned terminal in Pensacola. I showed up and nobody was home. The way that works, you show up and wait until about sundown when the drivers start returning and you pounce on the first guy who shows up to demand your load. If you live in a bigger town you’ll probably have a better experience.

Well, a driver came, I pounced and he went off to a storage trailer with his forklift and returned with my pallet. It was leaning, which I took to be a bad sign. A guy in California builds these pallets and then the truckers attempt to break them. This time the trucker won and I got, if I remember right, 13 busted panels in the lot. Sun Electronics refunded the price of the busted units, but I no longer had 50 panels. I had my heart set on 50! Well, that’s how it sometimes goes. I checked and it seems my experience is the exception to the rule.

Well, here they are. What can I do with them? First of all, I need a quick and dirty solar lighting system for my boxcar. It is really a 40′ shipping container, but it looks like a boxcar, so that’s what we call it. It is also a long black hole. I strung LED light strips from stem to stern, plugged them into a cheapo car inverter, connected that to my hot spare 200amp sealed 12v battery, which is regulated by a 40 MPPT controller from my junk box and that is wired to 4 of these panels in parallel. Remember, these things put out about 100v, so you don’t want to get carried away with series strings unless you are doing a high voltage grid tie system and you will need an MPPT controller for battery systems.

Plenty of solar-powered light, even all the way in the back.

I have the greatest of intentions for mounting these panels properly after I put a seal coat on the top of the boxcar. Right now they are just up there on the roof. To complicate solar production they are not only horizontal, but they are in a deep forest where there is rarely a bit of direct sunlight and leaves are constantly falling. Sounds like a challenge, eh? That’s exactly why I chose the thin film panels for this project, because they work well in diffuse light and don’t mind a few leaves. How well are they producing? There is no way of knowing and it is hardly fair to judge them in a case like this. All I can tell you is that whenever I need the lights, they work.

I did another setup at the Solar Shed that is not only pretty conventional, but I have a recorder on it and am getting some data that I can compare with the other arrays.

The 12 horizontal panels are the $7 modules. They are rated for a total of 840 watts, though the sun is too high for full output now. The three 60 cell panels just to the left make almost the exact same power. Thin film panels make all the power you need, but they take up more space.

I put a dozen of them on the wooden test racks below the eaves of the Solar Shed. 12 x 70 will ideally yield 840 watts. The angle is way too steep for summertime, but I can compare with some poly panels mounted on the same rack. If you are into that sine and cosine stuff, we should expect around 70% of rated power this time of year.

The first bit of advice I am going to give you on mounting is don’t mount them on a wooden rack. Wood does not seem to die until you burn it. When it is dry it will twist this way and when it is wet it will twist the other way. My clamps were a little too snug on a couple of the modules and I ended up with two more broken ones. BUT, they still work, so I left them in place, for now.

Again, there is no metal frame, so you use clamps. I used rubber-backed discs, but the original setup used flat bars that you could probably duplicate with aluminum bar stock from Home Depot. A backing of inner tube rubber would be a nice touch. It really is pretty simple. You cannot mount them on a flat surface because the junction box is on the back of the panel. Mine are on wooden rails, but I recommend you go with more stable metal rails to avoid breaking them.

That’s how it SHOULD be done! Polycarbonate greenhouse channel should work nicely, too.

Since a MPPT charge controller typically maxes out around 150v, I just wired all 12 in parallel, using a special combiner harness I built. I can plug or deplug any of the MC3 connectors if I need to troubleshoot. I have plenty of controller capacity left, but I wired up this dozen independently so I can check performance. If I decide to make a permanent thing of this, I will run the power from this array through a combiner that includes diodes so the slight voltage mismatch won’t cause trouble. We don’t want the polys and the thin films fighting.

A quick and dirty test stand for the FS-70 modules to tie into my 48v Solar Shed system.

So how are they doing? I realized early on that I was probably missing a few watts because the system would charge up and the controller would cut back. It is pretty much running all out, now, by adjusting bulking and floating points just a tad higher than the other 5 charge controllers.

So far, they have produced 57 kwh and have averaged a bit over 2 kwh per day in this rainy season with a bit of Sahara dust cloud mixed in. I have seen 3 kwh in a day. I have observed a peak power of 572 of 840 rated watts. Given the steep mounting angle, that is just about right for the panels running at full rated power! John was worried that they might have lost a lot of capacity, but they are great!

Here are some random comparisons with a 1000 watt set on the same rack.

170/840 vs. 161/100 under overcast conditions.

439/840 vs. 400/1000 hazy

69/840 vs. 71/1000 very late and cloudy

345/840 vs. 320/1000 at 1pm under hazy sun

As you can see, the thin films sometimes outperform the larger poly array! I am betting the poly will do much better on the cool, clear days of winter.

I will continue monitor these panels for a performance update.

Conclusions? You’ll need to treat these a little more gently than framed panels, they’ll take up a little more space and they’ll cost a little more to ship, but with their handy size they are great for a DIY’er. You should be able to put together a first rate solar power system at a rock bottom price.

–Neal

Scoundrels and Scalawags

There are good deals. There are bad deals. There are scoundrels who will try to tell you their bad deal is good. If you don't want to deal with all the razzle dazzle in solar power systems, do it yourself and you will know exactly what you have.

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Look to the West

The rule is that solar panels have to face the south. Some of us break the rules.

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What’s a Combiner Box and What Do I Want to Look For in Mine?

It is a weather-tight box that combines the outputs of a number of solar panels before sending the power to the next level of equipment. It can be simple or very elaborate. I was recently looking at them for a project I have.

Solar panels are sometimes used as singles in parallel or in multiple series strings. Running a wire from the roof or backyard from every one of those panels or strings would use an awful lot of cable and it just isn’t necessary.

For example, I am going to review some of these super cheap $7 thin film panels John has for sale. I had room for a dozen of them come available on my test rack, so there they are. These panels can put out nearly 100volts EACH, so you can’t really string them together for a typical 150v MPPT charge controller. Obviously they were meant for string inverters, but if you are going to be a tightwad like me, you have to be creative.

So what I am going to do is run them all in parallel. Because they are high voltage output and only 70 watts, they are going to make less than an amp each. That means the power from all of them can come back to the control room on a single 10 gauge solar cable. THAT is where the combiner can come in handy. We have to get all 12 pair of wires connected to one pair of wires.

Some combiners are super simple, consisting of just a weathertight box (because this is out in the weather with the modules) and some barrier strips to connect the wires. Some take it a little further and add a fuse for each panel or string. You can even put a surge protector in there. Rooting around on the Sunelec.com website, I noticed one he had has a little bit of DIN rail in it, so you can clip on all kinds of different options.

Some have built in MC4 connectors, the most popular type. These cheapo modules use the older MC3 connectors like my shingles. You don’t see them much, anymore, but there was one combiner box that even had long pigtails spaced for running directly to the modules. Handy, but not cheap. Well, maybe it is cheap enough. Sure, this is not rocket science and you could probably build your own combiner boxes, but by the time you source and purchase all the bits and pieces and then wait forever to get the bits and pieces, you can see that maybe it is well worth the price. Using a combiner box will give you safe and durable connections.–Neal

I found this one in the picture collection. It is super simple. It has a couple of bus bars, breakers and DIN rail to mount whatever else you need. I would not be surprised if Roberto has some other varieties stashed in the warehouse, too.
July solar arc at the Solar Shed

What Do Cemeteries and Solar Arrays Have in Common?

A Cultural Resources Management (CRM) firm recently had a question about an old water-powered mill in our county. You don’t think much about water power in a state as flat as Florida, be we had lots of them. US 29, through Escambia County, could have been named “Industrial Boulevard” there were so many. The firm contacted the University and the query was forwarded until it got to me. I worked on the mill survey a couple of decades ago and am a go-to guy on mills and local history. That query led me to look into the history of the family that owned it. I discovered on a genealogy site that they had a cemetery and nobody knew where it was.

That struck me as a challenge, to find the cemetery. It was an exercise in armchair archaeology, followed by a trip to the field…a fun activity during lockdown, as I’d only be around dead people. I found dead people, thanks to Lidar topgraphy mapping.

There were depressions in the ground, indicating 3 graves. Genealogical reports indicated there should be 3 graves, dating from 1825 through 1849. The family had come here in 1819, when Pensacola was still a Spanish colony and they were prosperous planters.

The graves had been marked with wooden markers. I found bits of pine knots, but nothing that would indicate who was in which grave and I was curious about that. Could I properly determine, by non-invasive means, which person was where?

Mary Ann, the matriarch died first. Then her grandson John. Then John’s mom, Lucretia. I have dates of death for each and when I return I should be able to determine who is where!

How, you ask? By the angle of the sun. Everybody knows the sun rises over there and sets over yonder, corresponding to some variation of east and west. Once you get a solar array, you start noticing a little more. For example, right now, in June, the first and last rays of the day are on the BACK of the Solar Shed! A fat lot of good that does. The sun isn’t moving in a straight line. It travels in an arc. In winter, that arc swings further to the south, beginning and ending closer to actual east and west. The nature of this arc will vary according to where you are.

Now back to cemeteries, most cultures will plant you in an east-west orientation. Modern cemeteries have very precise placement of graves, making things very compact and tidy. In the older cemeteries, sometimes charted using ground-penetrating radar, you’ll see some variation, with the direction of the feet swung a little to the north or south. That is because burials were aligned with the sun and not a compass. Therefore, I should be able to get the angle of the sunrise on a given date and match it to a particular grave. I think it is a pretty sure bet that Little John is between Mom and Grandma, so the real question will be who is on which end. I can’t wait to get back out there and take my measurements.

There are websites and apps that can calculate and display the sun’s arc for any particular time of the year, in case you would find such info handy.

July solar arc at the Solar Shed
This is my place and the red target is right on the Solar Shed. The light orange line on the right shows the angle from the Solar Shed to the rising sun on July 14. The darker orange is sunset. The yellow arc shows the path during the day. The fat yellow line and the orange dot were calculated at 4:30pm. There is still lots of sun, but you can see it is now shining on the back side of the shed! Maybe we should rethink this whole “point it south” business. This image was created by www.suncalc.org.

But back to solar power, alignment of the solar panels can make a big difference in your power production and your best angles might be determined by how you use your power. Mine are pointed southward at roughly the same as my latitude, a general recommendation and they perform very well in the winter when the sun is lower and more southerly. I don’t use as much power in the winter because I have a wood furnace and do not use the heat pump. I could use the heat pump to save wood, but I have more wood than I can possibly use.

In the warmer months, the sun is not straight into the panels at noon and it spends a couple of hours shining on the back of the shed. I would be better off with the panels just flat, like on my boat.

Expansion plans for the Solar shed include another 32 feet off to the west, using active panels/shingles, and a carport on the backside for golf cars and lawn mowers, using dead shingles. Now I am rethinking this. Maybe put the dead shingles on the south roof, because I have plenty of winter power, and live shingles on the north carport roof to capture the early and late rays. Maybe the guy whose house is featured in John’s Blog had the right idea.

A solar array to follow the sun's arc.
Yeah, in my dreams.

Yeah, I like that idea, but what is immediately obvious is that solar modules are the wrong shape. They need to be in a keystone shape to maximize the panel area on the roof!

Of course, if you are ground mounted, you can use a tracker. These are available in single and dual axis form. They can be very expensive to buy and install, which raises the question: tracker or more panels? The big boys, who do enough of this stuff to know go both ways. It may just come down to available space. Most of the commercial farms that I have seen with trackers use a single-axis system. That just swings the array from east to west and should make a very big difference.

My own array makes plenty of power, but not necessarily when I need it. I could get by with a smaller pile of batteries, I suspect, if I could put more of that hot afternoon sun directly into my air conditioner instead of on the back of the shed!

This fall, I will be helping my friend Courtney with a new tracking array installation in North Carolina. Stay tuned for a report on the installation and the performance.

Now about that family that misplaced their cemetery, the bulk of them moved to Mississippi in 1836 after planting had depleted the soil here. John Sr. followed later, after Lucretia died. After depleting the soil at their Mississippi plantation, they moved to Texas and guess what? They forgot where they left the Mississippi cemetery, too! They are on their own finding that one.

–Neal

Thar She Blows!

Fuses offer cheap circuit protection, but there are some precautions you may need to take.

The H-Bridge locked up on my inverter recently. It blew a fuse. It blew it with a lot of self assurance, too. There was no dilly-dallying. Never mind what an H-Bridge is, but in this case it can handle 1200 amps, so when it locks up, something bad could happen. That’s why there’s a fuse.

A blown H-Bridge
An H-Bridge is 4 groups of transistors screwed to cooling fins. 2 sets turn on to direct the voltage output positive. They turn off and the other two turn on to switch the voltage negative. That’s how you turn DC into AC! However, if the WRONG two sets of transistors turn on at the same time, stuff will break. Fuses minimize how much stuff breaks. Or explodes. 12 of the 24 transistors died in the making of this story.

Usually, you kind of work your way up to blowing a fuse. The load exceeds the rating, the metal melts and everything stops. When you get over 1200 amps trying to get through a 150 amp fuse, you get a plasma bomb. The blast made a perfectly round hole in the mica window that is there to contain the failure and then it blew the plastic no-finger-pokey cover across the room.

The wife says there was lightning and then stuff didn’t work. So, you think maybe it blew a fuse and you go to replace it because you don’t know you have a locked-up H-bridge. You are careful because all of those capacitors in the inverter make a good pop anytime you put in the fuse. What happens, though, is not a good pop. You get a major arc that burns away part of the fuse holder and part of the fuse. Then the link BLOWS with great vigor, leaving you with black fingers. Being the cautious type, the fingers were on the protective casing of the fuse instead of over the window where the blast originates. The moral of the story is to be careful installing a new fuse.

There are different kinds of fuses for different purposes. Used to be only “T” fuses were used with inverters. I have used them when that is what I had, but they are very expensive. One thing I am pretty sure of, they would be hard to explode. Many cartridge fuses are filled with sand to contain and dissipate any excess energy they might encounter. I like ANL fuses. They are effective and dirt cheap. They are popular on boats and that is my upcoming primary wiring projects as I build the two Solar Yachts. They are not that good at containing plasma balls.

A disadvantage of cartridge fuses is that some holders can lose their spring tension and the connection can get a bit resistive, risking fire. For that very reason we had he circuit panel replaced at Mom’s house about 20 years ago. It was getting hot and smoky! Both the T and the ANL fuses are firmly bolted into place.

Whichever you choose, take care when inserting a fuse, especially when power is present. Remove the power when possible. In this case, there is going to be a pop somewhere. I would rather it be at a fuse holder than at the big plastic box full of explosive hydrogen (the battery).–Neal

That Time of the Month

You know, the time when you do your preventive maintenance.

Unless you have sealed AGM, Lithium or other such batteries you need to check the water at least once a month. Even if you do have sealed batteries, there are other things to check.

Back to the water, this is a rehash, but in case you missed it, keep a supply of distilled water and a box of baking soda handy. A rubber apron, gloves and safety glasses should be in your kit. Oh, you’ll need a wrench and a plastic funnel, as well. Keep the water up to the split ring. Use the baking soda to neutralize the acid that accumulates on top of the battery.

Make a note if a battery or cell uses more water than the rest. That battery may have a problem. If water consumption goes up all around, you could have a charge controller problem. I had a charge controller kill some fairly young batteries, so I know it can happen.

Keep the batteries clean and dry. After a washdown with the baking soda, give them a good wipe or they will be white and crusty from the soda. I find that a blow nozzle and compressed air can make cleaning a breeze, but not everybody has their batteries where they can get away with that.

You may need to clean the terminals, too. Acid fumes leak around the terminal posts and can make a mess of things. This can cause resistance, heat and wear on the terminals. Wearing safety glasses, I use a fine rotary brush in a cordless drill to scrape off the crud and polish things back up. A dab of Vaseline or even axle grease on the terminals and posts can help limit a recurrence. Since you may be stirring up some lead dust, you might want to add your Covid mask to your safety gear. Replace or repair cables, if needed.

Battery cable corrosion not only looks gross, but it can waste power and ruin cables.
Ewwww…..pull that off, clean it up, grease it and put it back. Nice and snug. Blow off the dirt and other stuff that does not belong there. Don’t forget to top up the water.

Even if your terminals are all clean and shiny, take a wrench to them. You’ll be surprised how they can get loose. I was at a guy’s house the other day. He isn’t big on maintenance and as he began his biennial battery check it took gallons of water to top the Trojans up and the terminals would spark under load because several were loose. Batteries need water because they turned the old water into explosive gas. Do you really want sparks around that??? Don’t wait two years to check this stuff. Batteries should last longer than two years, but not if you don’t maintain them.

My electric jalopy gets checked monthly, but it lives a hard life and had one terminal loose and two that were getting right colorful with corrosion. It does not take long. On the other hand, my boat uses an identical battery set and there are rarely issues with it. The difference, I think, is that the boat is a much cleaner environment. No dirt to accumulate with acid. The jalopy got its batteries cleaned, but with the work it does it will soon be a mess, again. Both the boat and the jalopy are part of the solar power storage. Despite the hard use, the jalopy batteries are pushing 6 years of service.

In the area where you have your charge controllers and inverters, you won’t likely find any corrosion, but those cables get loose, too. I keep the appropriate tools right there at the control panel so I don’t have to go hunting down the right Allen wrench or crescent wrench or screwdriver. Infrared, non-contact thermometer guns are helpful tools for a number of occasions in the solar biz, including checking terminals for poor connections by looking for heat. Yes, you can use a finger to detect heat, but there are places I personally don’t care to stick my fingers!

I have one set of batteries in one of my experiments I need to get to because it looks like a cat peed on them. I’m not really looking forward to cleaning that up. I can’t really prove it was Smokey, my big, half-wild tomcat, but he HAS been walking funny, lately. Add that lesson to your list of safety rules: Never pee on a 48 volt battery pack.

–Neal

Zero Export Grid Tie

They keep changing the rules on grid tie. Avoid dual meters, special fees and changing deals by mixing your power with that from the power company, without backfeeding to the grid.

Many years ago, a fellow came up with a gadget he called a synchronous inverter. Today we call it a grid tie inverter, and it changed everything. It allowed you to mix sun power DC current with the utility AC current. If you were using a heavy load, the solar power would replace some or all of it. If you were not using much of a load it would flow out through the meter, spinning it backwards to reduce the power bill. As long as you used a little more from the grid than you made with the solar, things were ok. This was called guerilla solar.

If the power company came by to read your meter and got a negative number because you made more power than you used, well that is when the trouble started. Some power companies forbid you to do grid-tie, some encourage it, some pay you to do it, some make you pay dearly and they’ll pretty much all require some special equipment. Your mileage may vary. Check with your local power company before you start.

My friend Courtney got lucky with his system. He lived in South Carolina where they actually paid him to add solar, plus he got Federal tax credits, so the whole thing came out pretty much free. There was a price to be paid in paperwork and jumping through hoops. He and I did the work, but he had to have a licensed electrical contractor and a NABCEP solar installer inspect the work before it could be commissioned. He also had to have a mechanical engineer sign off on his pergola being strong enough to hold the panels. It was strong enough for all the panels and the two old guys putting them up there, but it had to have the engineer’s stamp of approval. There was lots of paperwork.

On the other hand, there’s my power co-op that throws up every obstacle to grid-tie. I know of three people who have done it, but I can’t see where they are saving much. Others have had their power companies welcome grid-tie, only to change the rules later and jack up the fees.

Being the rebel I am, I have spent about a year studying how to use your solar power and not get the power company involved. One lovely way of doing this, used by Tom, is to use a grid interactive inverter. These can usually do grid-tie, but can also provide standalone power for use if the grid is down. During the day, Tom’s array charges his batteries and they feed the DC to the inverter that makes the AC. The inverter also has an input from the grid. As long as the batteries have plenty of power, the house runs on solar. Tom uses loads of power. Computers, TV, lights and coffee pot are always on. The inverter lets him select just how much he will draw from the batteries. He sets a fairly shallow draw to give the batteries longer life.

To accomplish this, Tom has a “generator plug” and a transfer switch. There is an actual diesel generating setup, but for everyday purposes, his solar system is the generator. So, a grid line goes to the inverter and the inverter runs the house. At night, the A/C will drag the batteries down pretty quickly and the unit automatically switches to grid power. If a hurricane takes out the grid and blows away the solar array, he can fire up the generator and charge the batteries with it or run directly into the house.

Tom’s stuff is not grid-tie, though. Courtney brought over a pallet of LG 300 panels and a case of Enphase microinverters and challenged me to see what I could come up with for operating an air conditioner from solar. No problem, except that I can’t do grid tie.

I played with the microinverters on my off grid system, which goes to my “generator plug” to see how far I could push it without a visit from the big white truck. I figured a plan and calculated how much my A/C compressor used and selected enough panels and micro inverters to match. The output of the microinverters went underground to the MOTOR SIDE of the big contactor under the hood of the A/C. When the A/C comes on, the microinverters are energized and they connect sunlight power to the cooler. Success!

Limited success, I should say. By Federal law, the microinverter has to wait 5 minutes before it does its thing. If you have a short cycling A/C, then that is a problem. Most HVAC contractors oversize their gear, but in my case I have a system for upstairs and a system for downstairs. The smaller upstairs unit is only 1.5 tons, but it keeps the house comfortable downstairs, if a bit chilly upstairs, while running nearly constantly on a really hot day. In this configuration it really saved a lot on my power bill and I had the house a lot more comfortable than if I were buying power. Best of all, I did not have to deal with the power company.

So here are the limitations. We are only saving power on the A/C, we are saving nothing at night and very little on cloudy days. Can we improve on that? Why, yes we can! It turns out these particular Enphase inverters have a form of limiting in them. Though they are being fed with 300 watt panels, they can only feed a bit over 200 watts into the power line. That isn’t as kookie as it sounds. It sort of levels things out when the clouds pass. It also means you can connect batteries to the microinverters and use the panels to charge the batteries through charge controllers. These micros are designed to operate from 60 cell panels, so a 24 volt battery bank works fine as a feed. Now the microinverters can microinvert at night or when cloudy, within limits of course. We saved even more on A/C.

Can we do better? Is there a way to feed the power to the whole house without spilling any out the meter? Yup!

So I ripped out all the microinverters and started over. First, the panels were arranged in series pairs and the DC was sent underground to the “dog house” next to the A/C units. In the dog house, two Grid Tie Interfaces, Limiter (GTIL), sometimes known as Zero Export Grid Tie, were installed, each plugged into a 110 plug from each leg of the 220 line. Some of you may be thinking, “Hey I’ve seen those blue boxes and they make one for 220. Why not use that one?” There’s 220, Euro style and there’s 220 American split phase. The bigger blue box does not understand the American Way.

Anyway, you plug these GTIL boxes into 110 outlets, add solar and, voila, grid tie. But not limited. You’ll get the visit from the big white truck and probably quickly if you have a smart meter. It’ll call home and you are busted! However, there are sensing coils that go in the big gray breaker box. They can sense if the power is coming or going. With the sensor coils in place, turned the right direction and plugged into the right box, the solar power will come rushing into the house wiring, filling every light bulb and small appliance, but when it tries to squeeze out toward the meter, the sensors stop it in its tracks, leaving maybe 4 watts coming from each leg of the utility.

In my case, the boxes are called “1000” units, but actually rated at 950 watts each. That may be a bit of an exaggeration. Still, under ideal conditions, they will handle most of the background load, but get overwhelmed a bit when the clothes dryer or oven are used. The dryer, for example uses 5000 watts, normally, but if the GTIL pair can knock 1500 watts off that, then that adds up to some savings.

Let me interrupt for a moment, in case you are thinking of getting some of these wondrous boxes. If you already have a grid-tie system, it is quite possible that adding a simple gizmo will allow you to do the same tricks with your existing gear.

Back to the GTILs I use, am I perfectly happy? No. For a couple of reasons, or more. First of all, the two inverters are connected to the same solar array. Solar panels are a somewhat high impedance source of power, which is to say that when you put a load on them, the voltage goes down. If one of the boxes is providing 800 watts to the coffee maker and someone starts up something substantial on the other leg, the solar source voltage drags down a bit further causing the first unit to trip out while the second tries to take charge. Before you know it a full-on fight ensues and nobody is contributing power. Sometimes both inverters will settle down in harmony and then a puffy little cloud goes sailing by and everything trips out again. Can this be fixed? Yes, to some degree, by simply dividing the array into two separate branches. The thing is, the solar panels are 200 feet from the point of use and digging trenches and pulling expensive cable is a bother. No, it isn’t quite as dire as that, in truth. I do have several cables in parallel that could be separated, but I have bigger plans, so no use getting involved in wrestling with heavy gage wires.

The next phase of the plan is to add batteries. Again, we will have power available around the clock, as we did with the microinverters. Batteries are a low impedance power source, so the two GTIL units should not fight.

The next step took some time to complete because I needed batteries. I looked far and wide for just the right batteries for my Solar Yacht project with the idea of running the house on them as a test and putting the old batteries, Sun 230s from Sun Electronics, on the GTIL project. Batteries, cash and opportunity converged and I had batteries.

The lines from the solar panels, LG 300s, operated in parallel pairs, for a total of 2400 watts, were disconnected from the GTIL units and reconnected to a 60 amp MPPT charge controller I found in a drawer. The output of that was connected to terminal blocks with connections to the battery and the GTILS. Oh, yeah, there were some fuses, circuit breakers and a surge protector thrown inline for safety. It worked.

Then Courtney wanted his panels back, so I put up a kilowatt of panels from a boat project. Less power, but since they were charging the batteries there is usually enough. Now the only limitation is high usage on a cloudy day, but isn’t that always the case?

Now the batteries can run loads any hour of the day or night. Cooking on the stove top? Covered. Electric clothes dryer? Knocks off nearly a third of that. Washing machine? Covered. Baking blackberry cobblers? Uses only about 1 kwh from the grid for a 5000 watt oven. There were two mystery loads that showed up on the monitors. They turned out to be a fridge and a freezer that had been left on the grid. They have been moved over to the all solar system, but they were being covered by the battery GTIL.

There was 72 kwh use from the grid this month, about half of last month. I had projected that it would only be 50 kwh, but in the corona lockdown, my wife deals with the situation by doing laundry. Many more hours of dryer time are being consumed than are actually needed, by my calculation, but my calculations don’t seem to count. I keep quiet about her laundry obsession and she makes me cobbler. I don’t mind losing a kwh to get a bowl of cobbler! The limited grid tie took care of an additional 67 kwh. The grid tie solar would have provided more power, but about the 6th day I discovered I had an unexpected load of a fridge and a chest freezer that had been overlooked. They were moved to the main solar circuit so they would be left running if the grid went down. They would have used another 72kwh from the grid tie.

OK, so if I have explained this properly, you may be wondering how you can get some of this limiting grid tie stuff, am I right? If you already have a grid-tie power system, you may be able to add the limiting system.

Most GT systems have an optional power monitoring module available that will allow you to keep up with your power use and grid interactions. Some of these have sensing coils available and they have the software to convert to limiting operation. Check your manual. It’ll probably be a very small mention. I know that SMA/Sunny Boy has a power meter accessory that can do this. Elgrispower.com has one they claim works with about a dozen different grid tie inverters.

No, if you are running a 600v string inverter system, you probably don’t even want to think about running batteries. If the power company decided to charge you a lot of money to connect grid tie, you can be rid of that nonsense because the power is being mixed in your house and never going out to join forces with their kilowatts.

If you have net metering or some arrangement that is satisfactory, then never mind. If your power company is trying to discourage solar and jacking up your bill with fees, then this could be for you. It is the rebirth of guerilla solar and may be just the thing to save you some money on your power bill.–Neal

What’s a DIN Rail?

And why would I want one?

No, DIN does not equate to a cacophony. It means for German Institute for Standards, or National Standard, bearing in mind that Germans spell things differently than we gringos do.

There’s all kinds of DIN stuff, so it isn’t just rails. DIN rail is a metal rail, usually aluminum or steel, about 35mm edge to edge and pretty much as long as it needs to be.

I first saw it in industry, where programmable controllers and other handy gadgets were mounted to control manufacturing processes. DIN rails and handy gadgets are great for solar, too. I buy short lengths of it on ebay, usually by the fistful. They are only a buck or two each, so that appeals to me. Then there are the handy gadgets. The items most used are fuse holders and circuit breakers, at least in my work. I saw a very nice combiner box the other day that was stuffed full of fuse holders and terminal blocks, all hung on DIN rail. Very nice.

Circuit breakers clipped to a DIN rail
Oodles of fuse holders on DIN rail
Spare parts stored on a rail. Power meter, timers, breakers, fuses. Lots of DIN-mount goodies are available.

I have bits of DIN rail here and there to store spare parts where I can find them. Look into them and see if you can come up with uses for them.–Neal

It’s Raining

And Tropical Storm Cristobal is on the way.

It looks to be heading to Louisiana, but Florida is getting the bulk of the rain. As far as storms go, this should be pretty mild, but you never know what tornadoes might pop up. Driving could be tough. Trees can fall on power lines.

Hopefully, those of us in the storm zone just get some soaking rains and our solar power will keep the lights on and set an example for our neighbors to follow.

Y’all stay safe out there.–Neal

Danger, 10,000 Volts!

Ok, you know I like to talk about safety, often based on experience, so here is a quick one I bet you haven’t thought about.

I am planning to try some of those 10 cent FS70 solar panels that Sun Electronics is selling and then write a review. I have actually used 4 of them in the lighting system in my “boxcar”, a 40′ boxcar-red shipping container. At the Solar Shed, some space freed up in my test rack, so I reconfigured for these modules. Next step was to fetch them and try them on a larger scale.

They are not big, but they are heavy, so I move them only two at a time. With one pair on board the Solar Yamaha, I went back for another. I am very careful with these as the panels can put out about 100 volts and some are missing the MC3 connectors, exposing bare wire.

So I curl my fingers around the corner to tip it toward me–there should be no wires at the corner–and, OMG!!!! 100 volts, my hairy hind end! It was more like 10,000 volts! I fully expected to see a charred nub where the finger used to be, but, no, there it was, all pink and healthy-looking, even if it did still feel like it had a hot nail driven through it. What the heck?

Then I saw the wasp fly out from behind it! Great! One more thing to worry about. If there is a moral to this story, it would be to watch out for Mother Nature. She is a practitioner of Murphy’s Law. Look out for wasps behind panels that have been leaning. Black widow spiders like to live under things on the ground. Don’t overlook the possibility of a snake or a scorpion under a pallet. It’s always something, isn’t it?

For a day or two, I went around with a hand that looked like those big foam “we’re number one” hands that people wear at football games. I learned a lesson I won’t forget and I am admitting to it so maybe you won’t have to learn it for yourself.–Neal

My Latest Power Bill Came

In it was a handout touting the cooperative’s dedication to service to its members. The coop power had been out for over 3 hours at that time, owing to a car vs. pole incident. A neighbor had power because I could hear the generator buzzing. I had power, too, but nobody could hear it.

Back to the power bill. I have been waiting for it with glee. How often to you hear of that? Pretty often when you are dealing with people who enhance with solar.

Power reductions with solar
This what happened when I went from JUST lights on solar (all the way on the left) to including a/c (NDJF) and then enhancing with limiting grid-tie (MAMJJAS). Below, you’ll see the chart rescaled and the results of adding battery to the grid-tie.

This was the culmination of efforts on one of my latest solar experiments. I have done a writeup on the whole deal, but I just thought I’d show the power bill first. $50. There was a time when I would have thought that was terrible. $9 of it was for electricity and the rest of it was….terrible. Fortunately I “don’t have” grid intertie, or they’d tack on another $50 service fee.

What I have done is put the “generator circuit” and a/c completely on solar. That left the big stuff. I added a limiting grid-tie apparatus that helped during the day, but it wasted a lot of power fighting for the solar. The latest revision is battery enhanced grid-tie. It works all day, all night and the two units never fight. This is what happened to the bill.

Power purchase reduction with battery enhanced zero backfeed grid-tie
The first 12 months used solar grid-tie, limited with NO back feed to the grid. The last month used battery enhanced solar grid-tie with zero back feed. Note that because of “fees”, the cost per day went down only 25% for a 2/3 reduction in use.

The reason any use showed up at all is that the oven and the clothes dryer each run at about 5kw and the little grid tie units I use are only good up to 1900 watts with the sun shining and a bit less at night. Several blackberry cobblers were baked last month, running up the power consumption, but well worth the expense of about 13 cents each. I’ll release the full story on this project in a day or so.–Neal

It’s Always Something!

Last week, during my morning coffee and internet infusion, I read of a very large solar power plant being planned for Bureau of Land Management (BLM) land in Nevada. Then, this morning, I read about a 6.5 earthquake in Nevada. Man, it’s always something going wrong, isn’t it?  Then I heard Puerto Rico had one!

It just goes to show that normal, everyday conditions are not the only ones to plan for. Here in Florida, we don’t get a lot of earthquakes. I recall a rattle or two, but nothing like the 1781 quake of 6.5 recalled by Chaplain Waldeck of the German mercenaries who were defending Pensacola from the Spanish at the time. That was enough to crumble chimneys and knock barracks houses off their foundations.

I wonder if there are special design considerations for solar in earthquake zones. Years ago, when I was providing management systems for distribution warehouses around the country, I notice that most had steel beams. However, in earthquake zones in California, Washington state and Alaska, the beams were wooden, because they would flex.

Most solar installations I have seen use galvanized steel posts or beams. Put a heavy mass of panels on top of that and the mass will try to stay fairly still while the poles take the shock and perhaps bend. I’m thinking there needs to be something springy or slidey involved in the mounting. I think I will look into seismic mounting to satisfy my curiosity.

Here on the Gulf Coast and up the East Coast, we have hurricanes. Forecasters were talking this week about a storm already forming and there was a weak swirling mass that went through Miami and is now crawling up the Atlantic coast as a tropical storm. Call those a warning. It is time to prepare NOW.

We have a long history of hurricanes here in Pensacola. Juan Tristan de Luna y Arellano and friends sailed into the bay in 1559 to set up a colony. A few weeks later they were holding onto trees for dear life while their ships were being bashed to bits in the shallows. Bienvenidos a Florida, amigos!

Despite this long history with hurricanes, people tend to forget the lessons. It has been maybe 15 years since we’ve had a good one, here, but we have had some whoppers on either side of us. Trees grow up along the powerlines and even a mild storm can knock the grid down for a while. Trees are tough on a roof, too. When hurricanes Erin and Opal came through, the stronger one did not cause as much damage as the first because the trees had already been taken out. The last big storm that came through was so strong it didn’t need any help from trees because the power poles blew over. When Hurricane Michael came through just east of us, it blew pretty much EVERYTHING over.

I had to repair the ceiling in 3 rooms at Mom’s house when a flying tree landed on the roof. She had backup power!

A battery backup system can help keep the lights on during and after a storm. The 2500 watt system I had back during the storms helped keep life fairly normal in the 5 weeks before the power company made it to our street. A daily top up of the batteries with the generator kept things going without the noisy generator running 24/7. NOW is the time to act if you are considering backup. John’s guys already have some package plans, so it isn’t a big deal to get moving on this. My house was wired for this from the beginning, but any good electrician can retrofit this stuff, if you can’t do it yourself.

And what if you have solar power, already? Is it grid-tie-only or can it provide backup after the storm? A LOT of people who start out with grid-tie regret that decision when the grid goes down. There is equipment that will let you have it both ways! Maybe what you already have has an option you are not using. Check into it!

What about your precious solar array, assuming you have one? The Rocky Mountain Institute has a free report on what has been known to fail and what holds up against a storm. Find it. Read it. Essentially, use strong racks and use bolts instead of sheet metal screws.

In my own case, I know I have vulnerabilities. The solar shingles that Sun Electronics gave away are only rated for 60 mph. That worries me. That can be improved upon, but is way too much work. Additionally, I have a number of other modules on temporary racks. Steel stakes driven into the ground help anchor the wooden racks, but the panels are held on with screws. All of these panels I plan to remove and store in a safe place until after a storm blows over. Assuming Sun King, the solar boat, survives in its shed, it can come out and connected with the stored panels provide thousands of watts of solar input and its 5kw inverter can keep necessities running in the house. That’s the plan, anyway.

What else can you do to plan? Have some water stored for drinking and maybe a plastic garbage can full to use to refill the toilet. Kitty litter and a 5 gallon bucket can serve as a toilet if there are unpowered lift stations involved. There are ceramic water filters, like the Berkey, that can clean up pretty much any water source or you can make a purifier with a ceramic filter kit from ebay and a couple of plastic buckets.

Space was at a premium on the boat so I scaled down with 2 gallon paint buckets. Dirty water goes in the top, through a filter in the bottom of the top bucket and drains into the clean water chamber in the bottom bucket.

You need access to food. The virus situation has shown us how vulnerable we are there. Normally Walmart sells a 2 or three day meal package in the camping department. Sam’s Club will deliver a one year supply for the whole family, but right now you have to get in line. There are many options for camp stoves, including those that do not require commercial fuel, but if you have backup power, a microwave and a coffee pot you can prepare all sorts of meals. Yes, you can make pancakes in a microwave, if you know the trick! A single “burner” induction plate would be a good tool in your emergency kit. (My bro was camping at my place last week and used one plugged into an inverter to make breakfast.) Commercial MREs don’t last as long as the military stuff. I have cases of GI MREs dated 1984 that I would still eat in a pinch. Under normal circumstances, you could buy a big sack of beans and another of rice and be fine for a while. Cheap, easy foods seem to be in short supply, these days, but they can be found and it is best to set aside a bit for a stormy day.

You can’t prepare after a storm and supply chains are already strained with the pandemic, so get busy!–Neal

Size Matters

Reassessing capacity.

I read online solar news journals every morning while the coffee soaks in. Most of it is grid stuff, but those guys are in it for the money and have the bucks to pay for the research, so I pay attention.

I also paid attention when I lived very closely with my solar power during my 44 days aboard Sun King. What I learned there was that we waste an awful lot of solar potential. I had 1620 watts of panels, which is not a lot when you consider that it provided motive power, lighting, cooking and, most importantly, coffee. However, sitting there all day, arm’s length from the meters, I could see that by 10 or 11 a.m., the batteries were usually topped up and less than half of the solar power was being used to run the motor. The rest went unused.

I mitigated this, somewhat, by changing my load/use strategy. After about the first week, I’d get underway about 5 a.m. to burn off some of the 350 a.h. battery storage I had. That got me further up the river each day, typically around 50 miles and up to 100 miles, and I got to use more of those kilowatts shining down.

At home, I see much the same thing. By the time I get up and out, around noon, the batteries are often topped up or at least in bulk charge. The air conditioning season is beginning to make a seasonal adjustment to the load pattern. The house a/c starts up around 0930 and the man cave a/c in the Solar Shed starts around 10. I encourage my wife to use heavy loads, like the dishwasher (1kw) and cooking (separate solar hybrid, there) during the sunny hours. She baked me a blackberry cobbler this morning! She’s ok.

I honestly don’t know how many kilowatts of solar I have available right now, but I do know that I am not using all of it on a sunny day. I also know that when it is cloudy, I don’t have enough.

So back to the grid guys, that’s where the big money is and they keep coming up with bigger batteries and cool new gear. One battery beginning construction is rated at 100mw for utility backup. That is not mwh, that is mw output. Furthermore, it is rated to run for 150 hours at full output. 6 days at 100 MILLION watts! If you know the math, try calculating the number of John’s Sun 230 batteries you’d need to match that. Furthermore, the new chemistry of that battery uses water and air! Tesla has provided some pretty sporty lithium grid batteries in Australia, too.

All of this work is leading up to solar providing more power this year than coal. They can do this because they’ve been building an awful lot of solar AND they have been figuring out how to not waste it and continue using it after the sun goes down.

A new study from Wartsila (I’m sorry, but that name just conjures up an image of the offspring of Godzilla and a warthog) suggests the ultimate setup for the grid is to install 4.3 times the peak load of solar in sunny areas, with 4 to 10 days of storage. That may sound a bit extreme, but a utility can’t compel you to do your heavy power use only during the day, or even to be conservative in your consumption.

In looking at my own system, I have always tried for 4 days backup, though my ever-increasing load makes it closer to a single day if I maintained all loads and the sun didn’t come up. I’ve nearly 800 a.h., now and plan to add another 440 a.h. soon. That’ll give me nearly 60kwh of battery, but, of course, that’s only 30kwh at the usual 50% drawdown limit. I’m sure that won’t satisfy me, either, nor will it meet the Wartsila guidelines.

As far as meeting their guidelines on solar input, my inverter was tripping above 5500, so let’s say my current peak is 6kw. By their formula I should have 26 kw of solar input! Yikes! You guys will have John’s crew really hopping if you all install 26kw of panels! Or more. My best guess is that I have around 13kw actually running. I know I have two strings of around 720 watts each that are not working and maybe that much more up, but not connected pending the construction of the final bay of the Solar Shed. Just sitting in piles I have another 5 or 6 kw of panels that I have not nailed up, yet, but it seems I can get pretty close to their goal when the project is finished. My shortfall can be mitigated by not running street lights and traffic signals all night.

So that leaves batteries. Someday we should see all of this utility battery development trickle down to the solar homeowners. It is already, really, with the drop in lithium prices. At the present time, what I see is the cheapest entry into storage is the Sun Electronics Sun 230. Best bang for the buck, if you have the upfront cash, seems to be the SimpliPhi lithium. They are pricey, but should outlast you. Ask Roberto about them.

How does your system stack up to these new guidelines?

–Neal

Basic Skills

Let’s build some cables

I told you the other day I had reached the limits of what my homebrew 5500 watt inverter could do. I had a 10kw driver module to install, but it was bigger and was going to need some more cables.

One night I switched the house to grid, ran a power cord from the Sun King for lights and I shut down the inverter for a recon. What I found was that I could use what was in there, but I need to add some cables because a 10kw inverter eats lots more amps than a 5kw unit. I made measurements and notes and buttoned things back up a threw all the switches. Next day I built cables.

Tools and supplies to build power cables.
This is the kind of kit you’ll need to build cables. Stump is optional, but works better than your coffee table. Don’t worry, tree was cut with the solar-charged chainsaw.

John likes me to talk about the basics, so here was a perfect opportunity. If I were building this inverter from scratch, I would use four parallel #6 cables because they would add up to plenty of current and wire that is easy to bend.

I promise we’ll eventually get to the fun stuff, but we gotta do the book learnin’ stuff first.

keep torches away from children
The butane mini torch is handy. Kids love them. Just sayin’

Let’s start with the cable itself. I’m talking power cables here, for high current. These are cables you might use to join batteries or to go from batteries to inverters. How big do you need? Well, I want to run a 10kw inverter on 48 volts, so it is easy to find out how many amps. 10,000/48= a bit over 200 amps. NOW the question is what size cable do I need?

Look on the internet and you can find ampacity for various gauges of copper wire. I don’t like most of these charts because they relate more to how many amps you can get through the wire without melting the insulation or starting a fire than how much is safe, practical and has little resistance. I have a memory trick I use to come up with numbers I like. I can remember the common household gauges of 12 and 14. You use 12 on 20 amp circuits and 14 on 15 amp circuits in the house, though 14 gauge is banned in some places.

Wires and cables are typically even numbered and if you go down two even steps, you double the capacity. So going from 14 to 10 you double from 15 to 30 amps and from 10 ga. to 6 ga. you double it again to 60 amps. Some charts will say 6ga. will carry a lot more and it will, but it will get hot and drop some volts. If I were making a long cable, I would run less than 60 amps in 6 ga. cable. It boils down to USE A BIG ENOUGH CABLE. Or enough little ones.

But wait! Why am I building 60 amp cables when I need 200 amps? If I went with 4 60 amp cables, filling up all the terminals, I’d be good for 240 amps. No problem.

I’m not going to make it that easy, because the negative line already has a good 2 gauge cable. That’s two steps down from #6, so we double again. That’s a 120 amp cable. Adding my two 60s and we have plenty of amps.

Regardless of whether any of that sank in, we are going to build 6 gauge cables today, because that’s what I need for my project. My favorite cable for this is marine cable. It is fairly tough, very finely stranded and flexible and every strand is tinned. In some cases you might be required to use cable that is UL listed for solar applications. If you are wiring inside your inverter or making cables for your golf car batteries, then use what works for you.

What do we need? Wires, terminals and tools. I have a roll each of black and red #6 cable I’d bought for something else. Having both black and red makes it pretty obvious which is for positive and negative. Here’s a tip, bolt cutters make great cutters if you have a set just for cables. You won’t be happy if you cut the bolt first.

The inverter module came with some terminals that have foldover tabs. They are not my favorite, but they were free and they fit the screws. I also have some heavy duty tinned terminals, too. Terminals, by the way, are sold according to wire size and stud size. Putting #6 wire in a terminal made for 00 gauge wire is not a good plan. Match your terminals to your cables. It’ll mean having more terminals in the bin, but will make for better work.

You’ll need some pliers to bend over the tabs on the copper terminals, but don’t think that makes you done.

Prepared to crimp
Building a cable and working a camera is not as easy as it looks. Oh, bend those copper tabs over onto the cable.

You need a crimper tool. Some look like bolt cutters, except they crimp instead of cut. I have a couple that are like little presses that hold the terminal in place while you give it a couple of whacks with a big hammer.

Crimping a terminal
That’s right, the next step involves the big hammer. USE THE FORCE.

The tool I use works best when it is sitting on an anvil. My shed anvil has gone missing. There’s one over near the barn, but that’s a long way and it is heavy. Today, we are substituting the stump of an oak tree that dared to extend a limb over my solar array. Take that!

An anvil works better. Last time I lost an anvil I found it with a bush hog. That wasn’t good.

Back to tools, you’ll need a sharp knife. Keep it simple. I use a sodbuster and a lot of electricians use Barlows. A butane mini torch is very helpful for soldering. You’ll need a roll of solder, too. I like old fashion 60/40 rosin core. Never, never ever use acid core or stuff from the plumbing department. A good collection of shrink tubing is very nice to have for professional results.

Here we go, now. Determine how far back you need to strip off the insulation. Use the knife to go around gently, getting through the insulation without cutting the wire strands. For the open terminals, take pliers and bend over the tabs the best you can to hold it in place. On the tube terminal, just slip the cable in, making sure you get all the strands in.

Next, put your wire and terminal in the crimper and do the deed. In the kind I use, a “+” sign is embossed to show you got a good crimp. Some people are happy to stop here, but we are going to solder, too.

A crimped termnal
Oh yeah, that one is crimped

To solder, you’ll need your mini torch. A jet lighter will work on these smaller cables, too. Put the flame on the terminal, with the overshoot going away from the insulation.

Soldering a terminal
Don’t point the flame toward the insulation. We want to melt solder, not plastic.

On an open terminal, like our copper example, poke at the cable to see if it is ready to melt solder. Don’t put the solder in the flame. It will melt and fall into your shoes. On the closed tube terminal, poke the solder in at the gap between the insulation and the metal. When it begins to melt, run it on in. When it begins to puddle you have enough. A slight shake will get rid of excess. Let the cable cool before the next step. Warning: If you are making really big cables like 00 and 4/0 gauge, it WILL get hot.

Slip the solder between the insulation and the lip of the terminal
Yes, I know that doesn’t look like it is melting. I’m holding the camera, not the torch. The red stuff is shrink tubing. We’ll get to that once things cool down.

Shrink tube comes in all sizes and types. There is some really thin cheap stuff on ebay and you should avoid it. The best and most expensive is usually referred to as marine type. It has a melty inner lining that seals up both ends. This is great on boats and around battery acid.

Shrink tubing ready to shrink
We slipped the stiff marine shrink tube over the terminal in the middle. The red one below is cheaper stuff and already shrunk.

I like to keep red and black tubing to help denote polarity. Sometimes I only have black cable and the colored ends help keep things straight. Ideally, you own a heat gun to shrink the tubing. A hair dryer can work in a pinch. If you are careful, the mini torch works, too. Just back off 3 or 4 inches and keep the flame moving. You can screw it up in an instant.

Shrunk shrink tube
Now the black tubing has been shrunk. Notice the slight glossy bead of hot melt sealant that has oozed out and bonded to the insulation

One other handy trick is to buy CLEAR shrink tube. You type/print a message on paper, like “Main Inverter Cable, Positive”, slip the clear tubing over the cable and slip the message under the tubing. When shrunk, you have a permanent ID for that cable.

So there we have ’em, the new cables to go into the inverter project. I will eventually double up the 2/0 cable going from battery to inverter. The ones that are there are adequate, but I will have less resistance and voltage drop. Why double cable instead of bigger? First, I don’t do 4/0 cable. I can get it for the same price as 2/0, but I just don’t like it. Second, I have the 2/0 cable and maintain a supply of terminals.

In case you are wondering how the inverter project turned out, it went splendidly.

Inverter driver modules
I took out little guts and put in big guts
An inverter being upgraded.
This is the point when you wonder if maybe you should have left well enough alone. Note beneath the inverter I took the fuse out. You don’t need sparks at a time like this.

It fired right up without any complaints. I still have a few loose ends on changes to fans and control cables, but it is running and we’ve had no more overloads.

Success.
–Neal

Why Can’t I Tell Sea Stories?

John tells of the glories of swimming with the fish in Miami’s bays. Then he tacks on something solar. It’ll be a while before I get back into the water, but I have some solar sea stories.

I built an electric boat and it was great, but I couldn’t travel with it. I could easily do a 20 mile day trip, but I wanted to go places and explore. That is how Sun King came about.

It was a 16′ Luger Leeward hull stretched to 20′ to give it a more efficient stern. After much experimentation, I installed a single 80lb thrust motor, based on a Minn Kota troller. I outfitted it to do sidescan sonar bottom surveys of our local river. I’m a historian, among other things, and there’s a certain amount of history down there. It is a great boat for exploring rivers.

Did I mention that the electric motor got its power from 6 270 watt “B” panels? So there you go, a solar boat. Infinite range.

The first time I tried my river boat in a bay was nearly the end of me. It sits very low in the water and sometimes bay water does not sit low. Don’t even get me started on the Gulf of Mexico! Eventually I got things sorted and learned to deal with the limitations and I took some trips. Then I got this wild idea.

Have you heard of the Great Loop? Look it up. I know with Sun King’s limitations that trip is a nonstarter. However, there is what I call the Mississippi Loop or the Short Circuit. Essentially, the state of Mississippi, along with bits of Alabama, Tennessee and maybe some others, is an island!

You don’t believe that, do you? An island is, by definition, a parcel of land you can drive a boat around. You can drive one around Mississippi. I’ve done it.

I got in my river and went down to Pensacola, where I turned right and proceeded westward. I turned right again at Mobile and went up the Tombigbee River, which took me on up to Paducah, Kentucky.

The sun didn’t shine every day and on one stretch it went a good 4 days of cloud. I reckon I nailed the balance of solar power (1620 watts), battery capacity (350 ah) and motor load (625 watts at cruise). I did not go fast, but I went steady, often making 50 miles and maxing at 100 miles.

At Paducah, I turned to port (left) and went down the Ohio River to Illinois, where I turned left into the Mississippi. Yeesh. I was not prepared for the next thousand miles, but I survived.

Most boaters doing the Great Loop go south the way I come up. They don’t go down the Mississippi because there are only two places they can buy fuel, at Memphis and Greenville, before they make it to New Orleans. A solar boat doesn’t need fuel. I was doing something with my dinky 20′ solar boat that most boaters cannot do!

So here I am on the outskirts of New Orleans, docked behind the High Tide Bar and Grill and Marina and Convenience Store. I skirted the 12,000 hp pushboats, a hurricane and a tornado, but could I do the Gulf of Mexico? With this boat you want smooth water. Barring that, you want a wind on the stern and the boat will act like a surf board. Weather was lining up to go my way. It was going to be a matter of timing. I sought out local wisdom. I also sought flush toilets and real food. Noodle cups, MREs and Vienna Sausages are sometimes not enough.

I dined on Cajun seafood and monitored a discussion moderated by a young lady on where men could go in New Orleans for certain favors from ladies. She had everyone’s attention until she let slip that the aforementioned ladies were not actual ladies. Her audience pretty much lost interest after that and I looked at her more closely for signs of discrepancies.

I engaged in chitchat for a while with the guy next to me before being introduced to Rain Webb, the artist-in-residence. You didn’t know that a Bar and Grill and Marina and Convenience store had such, but this is New Orleans, mind you. Before he moved on he informed me that I was to meet with him aboard his sailboat later that evening. Oooookay. I don’t believe I have ever had such an evening of discussions on such a broad range of subjects. I really enjoyed it.

The next morning, Rain brought me a sack of avocados and oranges, to improve my diet on the final days of my voyage. He gave me a benediction, of sorts, informing me he was sending angels with me to protect me on my voyage. I thought that a bit odd, but this was New Orleans.

We checked with the cook, a former shrimper, who thought conditions would be good. Rain got in his kayak to guide me on a tour of the nearby fort and then guide me to Lake Catherine, where we parted company.

It was a short trip to the Pearl River, where I holed up waiting for the wind to align. The shrimper I met in a lock had called the waters ahead, “The Chopper.” I didn’t want to get chopped.

Finally, it was time to get underway. The wind was just right for the course I needed to sail, but I had to get around a point and had to tack back and forth to keep the boat dry-ish. Once around the point I was set. The seas were not dangerous, but they were not pleasant, either. After a while I realized that I was going to be out of luck if I wanted a cup of coffee or a hot meal. The galley was forward and I could not let go of the boat for a second. Fortunately, my custom was to rack up bottles of water and tea before getting underway, plus I had MREs behind the seat and Rain’s sack of fruit. I did fine, except for lack of coffee.

In the tedium of it all, it is sometimes difficult to stay alert and on course. I felt the boat bump something, which jarred me alert. I felt the bump a few more times and then was delighted to see I had been joined by a pair of dolphins! I decided they must be the angels Rain had sent with me. I was alert the rest of the way to Biloxi.

One of the angels escorts Sun King across the Gulf of Mexico

The next morning I got underway before daylight, leaving Deer Island around 0500, this time with better provisioning. I made good time to Mobile and owing to changing weather decided to charge ahead across Mobile Bay, which can be treacherous. Believe it or not, my angels were with me again, keeping me alert as night fell and I safely made it to Oyster Bay, a large puddle in the next county. That day I voyaged over 18 hours, dropping anchor after midnight. Solar powered! I know people with power boats that won’t or can’t travel that far in a day. Best of all, there was still enough power in the batteries to run the microwave to make supper that night and breakfast the next morning. I was on the home stretch and it seemed I no longer needed the company of angels. It would be another day and a half before I beached at my home port of Molino and called for the trailer.

Sun King in Pensacola Bay, 2015
Day 43. Sun King back in Pensacola. Almost home.

And that was the end of forty-four days in the sun. A few years later I had a transporter gig in New Orleans. I took the scenic route home and stopped by the High Tide. The place was abandoned and I was disappointed. I’d like to see Rain again, sometime, and tell him about his angels.

–Neal

I Finally Overdid It

What happens when you outgrow your solar power system? Plan ahead for upgrades.

Read More

Innovations

They are now making solar modules with power output in excess of 500 watts! Wow, that’s what I need for the Solar Yacht, instead of the 330s I have now. The thing is, you just can’t buy them, yet. The superest, duperest biggest and bestest go to the solar farms. Don’t worry, by the time the Gopher sets sail they will be available, but you’ll be wanting the 600s.

A few years back, someone came up with the idea of making a “microinverter” and sticking it right on the panel. You plug the panel into the microinverter and a big cable runs along the rows, connecting them to 220v. The solar power mixes with utility power and you get a smaller bill. I thought that was a really lame idea at the time, buying an inverter for each module, but the concept has grown on me. Someone dropped off a case of microinverters and a pallet of 300 watt LG panels, so what the heck? I gave them a try. I don’t have a grid-tie agreement with the power company, so I could not use them as intended. I used them in a most peculiar way and found them to be generally satisfactory, especially since I didn’t have to pay for them. Since I could not put them on my power line at the house, I connected them to the MOTOR side of the compressor relay in my outside a/c unit. Using just enough panels to cover the run current of the compressor, I pretty much got free air conditioning. The biggest aggravation with them is a legal requirement that they don’t kick on until the power has been on for 5 minutes. They are coming back to mind, now. I recall they have a communications bus. I need to see if I can use that for another off the wall idea! Can the communications bus turn the modules on and off or is it just for monitoring? Inquiring minds want to know.

5 minutes to start the microinverter was not a big deal last summer, when the a/c ran pretty much all day.

Someone has come out with a new idea for hanging stuff off the back of a solar panel. Now they want to hang a battery! That can’t be much of a battery, but it may not be as crazy as it sounds. It all depends on what they have in mind and I don’t have details on that, yet. It interests me because I am now running my grid tie system, with limiting to prevent inter-tie or back feeding, and I am feeding it with battery. Never mind the advantage of being able to take on nighttime loads, eliminating the variability caused by puffy cumulus clouds, UFOs, Black Helicopters and other troublesome shades you can maintain a steady output from the grid tie inverter (GTI).

I’m holding off on a full article on the subject until I collect a little more usage data, but this one change, adding battery to grid tie, is going to knock off roughly 2/3 of my grid usage, which is already pretty low. The reason it doesn’t get 100% is that I have a clothes dryer that my wife is not afraid to use and it can burn about 3000 watts more than the 1900 watt GTI system can provide.

I am going to keep watch for more of this panel-side battery business. In the meantime, if you go with any of this microinverter or other panel-mounted stuff…mount it on the back side! It’ll work a lot better.

What the heck were they thinking photographing a microinverter on the sunny side?

–Neal

Chasing Phantoms

I chased one and it wasn’t what I thought it would be.

A big part of living off grid or keeping the power bill down if you are on grid is efficiency. Try as you may to get everybody in the household to turn off unused lights or to not leave the fridge door open, there can still be waste. Some of this comes from “phantom loads” from devices that still use power, even when they are turned “off.”

Our first TV was a big wood cube of a Magnavox. It had no remote. The switch was on or off. Thank goodness, because all those vacuum tubes used an awful lot of power. Today, my TV has a red light down in the corner and it is glowing when the TV is off. Under the covers, there is a microprocessor that is constantly processing. Oh, the whole off-state consumption is less than just one of the tubes in the Magnavox, but it is power consumption, all the same.

Next to the bed there is a phone charger. It always draws a miniscule amount of power. At the kitchen table, the laptop charger is always drawing. The satellite and wifi gear upstairs is always drawing a lot power. My wife’s rechargeable hand vac stays plugged in long after it is charged. I have a shelf full of tool chargers out in the Solar Shed and they all have a light glowing, even when the batteries are topped. Look around your house and you may find dozens of such phantom loads.

Hey, I’m using free solar power, so what’s the problem? It was a big problem when solar was $10/watt. Not so much, nowadays when John always has super deals on solar power, but come a cloudy day, you can get deeper into your battery, which reduces its life, or you might be on the edge of capacity with your inverter.

It may be it doesn’t matter and it may be that you are just obsessive about efficiency. Handle it your own way.

If you do want to track down these little varmints and are on “lockdown”, now might be the perfect time. There are several tools available to help in your quest but the eyeball is cheap and effective. If it has a glowing LED and it isn’t do anything, “sic’em.” The original portable power meter was the “Kill-a-watt.” You plug it in the wall and plug the suspect into the outlet on the Kill-a-watt. The display tells you how many watts are burning away.

A switched outlet strip is the traditional way of dealing with these offenders. I don’t know about you, but at my house it seems that nearly every outlet in use is behind a piece of furniture. The switched outlet strip moves things into the open. You still may decide to leave that load running if, say, your TV wants to reprogram itself after every power interruption. You don’t want to dash in to view your favorite soap opera, only to have to wait an eternity for the programming to complete.

Another way to determine that you have phantom loads is through the instrumentation of your solar gear. My recent battery upgrade to my grid-tie system let me see what was going on at night. Let’s face it, traditional grid-tie doesn’t work very well at night! What IS this stuff going on all night? Power cycling higher, lower, off, and back on. It almost looks like a fridge, but all of my fridges are on the full-on solar circuits.

What the heck is going on in the wee hours???

I initially blamed my laser printer. That thing is possessed, I swear, and find it best to just leave it unplugged. I unplugged and found the instruments reading zero, so I thought the problem was solved. Then it came back, sometimes burning hundreds of watts.

In the “before times” I might have taken longer to track this down, but since we are “in the now” (I have recently watched all of the Mad Max movies, if you are wondering about the language) I went after it.

This involved pulling the big handle on the breaker panel from the grid. I knew what should go dark and what shouldn’t. Now’s time for “the telling.” The outlet for the aforementioned laptop charger was hot and it should not have been. The laser printer was right there, exonerating it, at least from grid power usage. It still isn’t off the hook for stealing wifi. When I got around to the chest freezer and big fridge, they were silent. Aha, what the heck?

It turns out that when I went to move that circuit from the grid panel to the solar panel box, I pulled the wire from the breaker next to it, giving my laptop solar power, but costing me perhaps 60kwh per month on my grid bill.

Well, adding the battery to the grid-tie is covering that consumption, but it is costing me a bit when I can’t cancel some of the power used by the clothes dryer when it is running. It also cycles my batteries a little deeper at night.

Now the question is, do I have room for another breaker in the solar box? In the “now times” it’s “time for the doing.” We’ll just see.

–Neal

Time to Change the Battery

Sooner or later, you gotta do it, whether it is the clock, the smoke detector in the hall, the car or your solar power system. Oh? You have grid tie and don’t have to change the battery? We’ll talk about that, too.

The batteries that I had on the main bank were in great shape, but there weren’t enough of them, especially now that the brutal air conditioning season has begun. One of the auxiliary banks in my EVs was getting punky. I think I got that desulphated and it is feeling much perkier.

No, the main thing is that I wanted to test a specialty battery before adopting them in the Solar Yacht project. I’m a big fan of GC2/T105 type golf car batteries, like Sun’s inexpensive Sun230 model, but dealing with acid and hydrogen generation in a closed area of the boat was presenting technical issues with which I did not care to deal. The easy way out is to eliminate acid and hydrogen generation.

That left a choice between lithium and some sort of sealed lead acid (SLA or VRLA). The cost of lithiums, if considered over the long term, is a great deal, but it is a bunch up front. This boat only has to last a year, and lithium might outlast me. My government funding budget, which is to say my Social Security check, demands a lower up front cost. John sells sealed batteries at a fraction of what they go for at the Marine store (the one out West) but doesn’t have the size I needed for the boat.

I found some used ones from a guy in Georgia. I don’t normally go for used batteries, but since I was testing durability and on a budget, what the heck? I figured I would get 8 for the main bank, four for the grid tie and one spare. The spare would give me an age-matched replacement should one of the others fail and, in the mean time, provide a robust power source for my 12v Solar Boxcar system. (It is actually a 40′ cargo container, but my wife thinks it looks like a boxcar, so it is The Boxcar.)

I thought to do a reality check. It seems that you can’t actually put 13 of these in the bed of an Avalanche. If you could, you’d break the axle. I settled on 9, which fit nicely and was only a wee bit over gross weight.

It was a nice outing for my brother and me. With Andy navigating, the 514 mile trip became 667miles, but we saw some interesting countryside. Two blocks from our destination there was a minor fender bender. Minor for us, that is. I got a silver smudge on my trailer hitch ball, which tore the fascia off the front of the RAM that rammed us. After acquiring our load, we headed to Talbot County, where I showed bro an old cemetery in the bounds of the old family plantation. He’d not seen it, before. I sprayed 200 year old tombstones with tombstone cleaner and he learned a little genealogy.

On the way to another family plot in Harris County, we passed a new solar farm under construction. It looked like progress may have been halted by virus worries. There were some neat, shiny rows and there were some torn up acres still piled with stumps, but no activity. After cleaning up some more great-great grandparents’ rocks we limped back to Florida, as a tire had gone bad somewhere along the way.

Then the fun began. Saturday, between old coming out and new going in, I moved over a ton of batteries. Literally. Another 500 lbs would wander over to the grid tie project on Sunday afternoon.

I was in luck. I had most of the cables I needed, already. Nice fat 00 cables with marine shrink tube on the terminals. I had to make one cable to join banks, but had the wire and connectors. When you buy supplies like this, always buy a few extra. If I hadn’t had these, then I would have been delayed for a week or two, waiting for them to come in the mail.

Overall, I only had to switch the house to the grid for a few hours and everything came back online without a hitch. It really pays to check everything twice, from voltage to polarity.

OK, listen up! This is where we get to the educational stuff.

The main bank is two strings of sealed VRLA batteries and the two auxiliary EV banks, when they aren’t elsewhere, are flooded lead acid (FLA). THEY HAVE DIFFERENT CHARGING CHARACTERISTICS. Time to reset the charge controllers.

Let’s go back in time a bit and I will tell you why I have been hesitant about sealed batteries. Tom, my nearest solar neighbor to the west (12 miles by air, 20 by road) bought 3 strings of the nice Outback VRLA batteries. He connected them to a 10kw array and fried them within two years. There was way too much charging current. There IS a specification for that. After some experimentation, I was able to bring most of them back. One gave its life to science. OK? So, you see that I am not wanting to kill my new batteries.

Reading the fine print (always RTFM*) I learned that you should not exceed 40 amps charge rate per string on these new batteries, should float them at 54.4 volts per string and you can bulk charge for a while at a higher voltage. Now the fun begins because I have 4 charge controllers, three different models and I haven’t been into the menus of two of them in quite a while. I set the twins at 54.4 and 54.3. I offset them a little so they don’t just drop out at the same time. Another controller had a menu selection for VRLA battery, but it has only one button and you have to combine short and long pressings to get where you want to go with it. Mo’ buttons = mo’ better, I have decided. Then there is the FM60. It is wonderfully adjustable, but there is a password and there is a trick to getting into hidden menus. Hint: shut it all down, press and hold the correct TWO buttons and turn on the breaker to the battery. There’s a whole new world of menus in that thing! Save yourself some grief…RTFM.

Next morning, I kept a close watch on charge rates and float voltages. All was well. Nailed it!

What about the EVs? They will be perfectly happy with the VRLA settings, but they won’t get into the equalization stage. They will have to be taken offline every now and then for equalization, which is basically a quick overcharge. DO NOT equalize sealed batteries! They burp out the gases, which cannot recombine to replenish the electrolyte. They dry up and die a horrible death. You mourn their death when you have to buy more. Don’t kill your batteries.

Now, as for the Sun230 batteries that I moved to the grid tie system, I think I will save that story for later. If interested, do your homework and look back through the blog for the GTIL or grid tie limiter stories. But yeah, we’re gonna put batteries on Grid Tie.

This is where the Sun230 batteries went

*Read The Freakin’ Manual

–Neal


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