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Does heat effect solar production

Does heat effect solar production

Hi All,

I have had my solar panels up and running since the end of April and even with a few monitoring issues that have been resolved I am happy with the system. One concern I have is that from the middle or end of July, I have noticed that my system is not producing as much electricity as it did earlier even though we have had a fair amount of sun. I live in Pittsburgh and it does get hot and humid here so I was not sure if that has anything to do with the production.

Thanks!

lilbean | 10. August 2019

Do you need to clean it?

Patrick | 11. August 2019

A few thoughts:

- After 3.5 years of enjoying our solar system in FL we’ve seen the highest generation during the spring months of March thru June. From there the generation gradually falls off each month for the rest of the year. Not unexpected as the days start becoming shorter after the end of June.

- Solar panels perform best at cooler temps, which is part of the reason for the reduced generation mentioned above.

- Thinking our rooftop panels might need to be cleaned occasionally, we sent a guy up to wash them a month or so back. Surprisingly he found no dirt or crud on the panels. Apparently mother nature’s solvent does a pretty good job....

Suggest measuring your generation trends over time. Also - most inverters have online diagnostics to verify proper operation of each panel and the inverter itself.

johncrab | 11. August 2019

Short answer is YES. Solar panel output efficiency starts to degrade once the matrix temperature reaches 100ºF (internal, not ambient). At 110ºF you are likely to see a 5-10% drop in output. At 140ºF, 20-25%. This is just temporary and as the panels cool down, they go back to full efficiency. Now for the joke and something that I would expect in a military manual: "To prevent panels from overheating, they should be shaded from direct sun."