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Unfortunately, solar panels get less efficient when hot, which is when your AC demand increases. Ideally you could offset this by having people who aren't well
by __MatrixMan__ 3y ago
Unfortunately, solar panels get less efficient when hot, which is when your AC demand increases.
Ideally you could offset this by having people who aren't well positioned for panels do energy storage: Buy in the morning, sell back in the afternoon. Practically I don't think the utility companies are going to cut them in on a big enough part of the profits to incentivize them to do so.
- breischl 3y agoSorry I stated my original point poorly, and it wasn't exactly what you were saying. My bad. Demand response for A/C tends to look more like pre-cooling before the hottest hours, then reduce demand during the hottest hours. So it's not about shifting demand towards maximum production, but rather shifting demand away from the demand peak (aka, peak shaving). So it's similar but a little different. >Practically I don't think the utility companies are going to cut them in on a big enough part of the profits to incentivize them to do so. The commercial version of what I stated in the previous paragraph (ie, demand response/peak shaving) empirically already happens, and has non-trivial dollars attached to it. Again, maybe not exactly what you're talking about, but it rhymes.
- duckmysick 3y ago> Unfortunately, solar panels get less efficient when hot, Less efficient by what factor?
- edent 3y agoBased on my experience - about 12%. See https://shkspr.mobi/blog/2022/07/solar-efficiency-and-high-temperature/ https://shkspr.mobi/blog/2022/07/solar-efficiency-and-high-t... That will depend heavily on local conditions, type of panel, etc. Significant, but not devastating.
- duckmysick 3y agoThat's pretty cool! 10% was my educated guess. It's good to have some data points. Would you say the same holds across months? Say, would cooler May have better production than hotter July? Or is July still ahead because of more sunshine hours, offsetting the hot inefficiencies?
- edent 3y agoIt really depends on the weather. You can see my monthly generation at https://pvoutput.org/aggregate.jsp?id=83962&sid=74451&v=0&t=m https://pvoutput.org/aggregate.jsp?id=83962&sid=74451&v=0&t=... Sometimes May beats July, sometimes it doesn't. If you're interested, I have released all my panels' data at https://gitlab.com/edent/solar-data/ https://gitlab.com/edent/solar-data/
- duckmysick 3y agoThanks. This is all very interesting, I love graphs like these. I see the pvoutput page didn't pick up some days in May and June 2020. I'm curious why, since I can see them on your .csv dumps.
- edent 3y agoProbably because my Internet connection went down.
- stephen_g 3y agoI'm in a hot climate, I find in general with my system that the length of the day dominates over the loss in efficiency so December (southern hemisphere) is always the peak generation for me. January we usually have storms and rain due to the humidity so that's not usually as good, but it seems to be pretty reliably due to that shading from the cloudy and rainy weather more than heat.
- Neikius 3y agoI don't remember the numbers but I did watch this YouTube video where a guy strapped on some fans to a solar panel and actually got a better yield fan usage included.
- duckmysick 3y agoNow I'm wondering if it makes sense to cool them with water and reuse that heated water for washing and showers.
- guerby 3y agoAround 0.3% less watt per degree C It's usually given in the datasheet of the panel.