Look to the West

Lately I have been thinking and talking about capturing the afternoon sun. Now I am doing something about it.

You may have seen in previous posts my thinking on capturing the afternoon sun. By 4:30 pm there is NO direct sunlight on the southern arrays. Here is how I did it. I would eventually like to extend the solar shed another 32 feet, but those plans are on hold owing to other priorities.

What was covering the end was plywood coated with brown stain. Today’s stains are just about useless, so it was beginning to look a little rough. Covering over it would be a mercy. I have lots of the solar shingles that John was giving away a few years back, so that is what I used. They have a finished size of about 13 x 35 inches and put out 34 watts at maybe 5 volts.

On those specs, take them with a grain of salt. They were all stomped and thrown off a roof when removed from service. They all have cracked cells. They work well or not at all. I chose some that work. The wall is 12′ wide, so I can put 4 of them side by side. I can go 4 rows high and then it gets tricky because of the diagonal cut of the roof. Potentially, I am looking at a tie for the ugliest solar installation, but then I have an idea that moves it to a more fashionable installation.

These are shingles, so they overlap. The problem is they make a shadow and polycrystalline cells aren’t good with shade. So I put them in upside down. Treated 2×4 purlins are screwed to the wall at the proper spacing. The panels are wired in series as they are installed. To solve the angle problem and give a nicer look, I take some bad panels and make diagonal cuts to match the roof line. Yes, you can cut solar panels with a circular saw. Wear safety glasses of course, because there will be flying glass. Not as much as you might think, though, because it is stuck to the laminating sheet.

In this mockup, the panels/shingles on the right are mounted properly, but you can see the shadowing on the lower panel. On the left, they are mounted upside-down and have no shadows. The angle to the sun totally sucks! Oh, and yes I know these are busted…they are just for fitting.

I ended up with 24 panels, hopefully around 816 watts. This will match nicely with my roof strings and I could just add this to one of the existing charge controllers, but I want to be able to tell you how well this crazy scheme performs. Instead, I put in a dedicated charge controller. This one has recording capability, so I should be able to report on how well it is performing. As it stands now, between bad weather and a Saharan dust storm we have not actually had any real sunshine. That’s all part of it and the recorder will tell the story. I can tell you that there is a time in the afternoon when the west wall performs better than the south facing panels!

I’ll give this a month and report back with results. I will also try to get some custom flashing made to pretty things up a bit.

–Neal