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Figuring out solar panel efficiency on different roof angles
I've been messing around lately trying to figure out how much difference the slope of my roof actually makes for solar panel output. I mean, we all know angle matters, but I wanted some real-world numbers, not just the theoretical stuff you find online.
Here's what I did: first, I got myself a simple watt meter and hooked it up between my panels and inverter. Then, I built a basic adjustable frame (nothing fancy, just some scrap wood and hinges) so I could tilt the panels at different angles. Every day around noon, I'd set the panel at a specific angle, record the wattage output, and jot down weather conditions too. Did this for about two weeks, changing angles every couple days.
Afterwards, I plotted everything out in Excel - yeah, nerdy, I know - and it was pretty clear which angles gave me the best bang for my buck. But now I'm wondering if there's an easier or more accurate way to do this without spending weeks fiddling around on my roof.
Has anyone else tried something similar or found a better method? Maybe some kind of app or gadget that simplifies things?
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2 replies
"Every day around noon, I'd set the panel at a specific angle, record the wattage output, and jot down weather conditions too."
That's some solid dedication, but honestly, two weeks might not be enough to capture seasonal variations. Sun angles shift quite a bit through the year, so your ideal summer angle won't necessarily be optimal in winter. Maybe try using one of those solar pathfinder tools or apps - they map out sun exposure year-round without you climbing up there every day. Could save you some hassle...and splinters.
"Every day around noon, I'd set the panel at a specific angle, record the wattage output, and jot down weather conditions too."
Gotta hand it to you - that's way more organized than I was when we first got our panels installed. I just eyeballed it and hoped for the best! 😅 Agree about seasonal changes though; our winter output dropped noticeably, even after tweaking angles. A solar pathfinder sounds interesting...might check that out myself before winter hits again. Good luck with it!