It Doesn’t Have to Be!
Of course, there was no electric water heater, but the grid powers a small fan in the outdoor wood furnace. That’s a fair trade-off there. This phase of the system was very limited, but also provided power for loads the house never saw. A Yamaha golf car replaced an F250 as my on-farm truck. At that time, the Yamaha was a just a load and not a battery resource, like it is in the present system. There were also lights and power tools run by the system and no attempt was ever made to meter this.
Firing up the amps with solar can save on the power bill, too.
Here is what the power consumption was looking like over a period of time. This is from my July 2019 power bill. The last “J” is the July bill, but for the June electricity. Look back 13 months to July 2018. That’s actually June, when it is pretty mild. August (July) ran on up to 837kwh. That’s without paying for the lights, of course. Note the plateau for November-February. That’s running the house without heating or cooling, aside from the air handler fan. Then in March we see another step down and then it just doesn’t go back up. There was another change.
What happened was the bigger 48v solar power system got switched over. It had been running for months, but there were some wiring changes and other things to consider, including minimizing downtime during the changeover. I knew the new system was stable, having run it alongside the 24v system. When I changed over, I put the extra power to work, cutting over the two fridges, freezer, home entertainment, some outlets, dishwasher, microwave and both coffee makers. We are serious about our coffee. That got us down to the 200kwh neighborhood, at least until cooling season begins.
The new 48v system under construction, before lightning blew up the 12kw inverter.
Getting through spring with most loads off the grid was easy. The challenge for summer was to get the a/c running on solar. The homemade inverter just couldn’t handle the surges. Read the a/c blogs to see what happened there. Short version is, it worked.
The new inverter under construction, using case and transformer of the old inverter. Note the MidNite Solar lightning catcher down near the bottom left. I love the cool blue glow and the thing actually works!
The homebrew inverter comes to life on the barely running 48v system. There are still 378 small solar panels to move over! Yeesh! Those stupid magnetic “light switches” are actually quite handy to stick to your system, just in case…
So here is the result of running the big cooling load, the lights and basic appliances on solar. The August bills from last year to this year dropped 600kwh, even while keeping the house cooler and powering 2 utility vehicles. So the next question is when do I upgrade my inverter to 10kw (I have the parts) and pile up some more battery capacity? The inverter upgrade is just a matter of finding time. Come January, the Solar Shed will be getting its last expansion, stretching from 80’ to over 100’, depending largely on how many working solar shingles I can come up with. Maybe an additional 3500 watts! The cost of building materials has gotten crazy, so we’ll get that part out of the way before we talk new batteries. The current set is in good shape, so no sense in spending 5 grand on a new monster battery, just yet.
The September 2019 power consumption of 210kwh is pretty remarkable when you consider how many days we had over 100 degrees F.
If you’ve not read some of my other posts, you may be wondering why I am not just running grid-tie. That’s not an option with our power co-op, so the only time we even talk about it is to gripe that we don’t have it. So, hybrid systems are the way we go. Proof is in the power bill that it is working. Now as for Connie’s problem, I’m going to sit down with her and see if there is something we can do with solar to help her bill. Yeah, I could tell her to turn up the thermostat 5 degrees, but I don’t have a good track record getting women to do as I tell them, so I won’t bother. If we can cut $200 a month during the summer months with a microinverter conversion to her compressor, that could pay for itself in a reasonable time, especially with the cheap prices on the pv modules from Sun Electronics. I’m sure she has a heat pump (which I hate), but she might not see great savings in the winter if she really ices down the place, then. I’ll let you know if we come up with a successful plan. –Neal