4 ms·

> Unfortunately, solar panels get less efficient when hot, Less efficient by what factor?

edent 3y ago
Based 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 ago
  That'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 ago
    It 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 ago
      Thanks. 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 ago
        Probably because my Internet connection went down.
  - stephen_g 3y ago
    I'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 ago
I 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 ago
  Now I'm wondering if it makes sense to cool them with water and reuse that heated water for washing and showers.
guerby 3y ago
Around 0.3% less watt per degree C It's usually given in the datasheet of the panel.

Based 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 ago
That'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 ago
  It 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 ago
    Thanks. 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 ago
      Probably because my Internet connection went down.
- stephen_g 3y ago
  I'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 ago

I 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 ago
Now I'm wondering if it makes sense to cool them with water and reuse that heated water for washing and showers.

guerby 3y ago

Around 0.3% less watt per degree C It's usually given in the datasheet of the panel.