Is there an overheating electronics issue w/ rooftop solar ?

[ElectricTundra]

A friend mentioned that ground based solar is better and more efficient (per panel?) because it stays cooler. E.G., rooftop solar gets hotter and is less efficient.

Accurate?

 

[mspohr]

Solar panels do put out less power when they get hot. You can find the specs for your panel.
For instance, Solarworld panels have a TC Pmpp -0.39 % /C which means that the power decreases by 0.39% for each degree Celsius.
If your panels don't have good ventilation, they will get hot and deliver less power.
I note that I get highest peak power from my panels in the Spring and Fall when it is cooler.
I have 16 pole mounted panels with good air circulation and 8 roof mounted panels with about a 8" space.
Yes, rooftop can be less efficient but it is a small amount and there are other factors which may be more important in the decision between rooftop and ground mount.

 

[jsmay311]

Yes, rooftop can be less efficient but it is a small amount and there are other factors which may be more important in the decision between rooftop and ground mount.

I wonder if the OP was thinking more about solar shingles (which would have no ventilation underneath) than roof-mounted solar panels (which would have ventilation).

I imagine this temperature/efficiency issue would quite a bit more significant with solar shingles.

 

[ElectricTundra]

@mspohr, Are your pole & roof panels the same? Have you noticed any difference in production? How much difference do you notice between hot and cooler days?

Thanks,

BTW, not thinking specifically about shingles (though I'm on the list) but solar in general.

 

[mspohr]

@mspohr, Are your pole & roof panels the same? Have you noticed any difference in production? How much difference do you notice between hot and cooler days?

Thanks,

BTW, not thinking specifically about shingles (though I'm on the list) but solar in general.

Roof and pole panels are the same but different orientation so hard to compare.
Difference between hot and cool days is only a few percent.

 

[nwdiver]

A friend mentioned that ground based solar is better and more efficient (per panel?) because it stays cooler. E.G., rooftop solar gets hotter and is less efficient.

Accurate?

I have a ground mount and roof mount in Andrews TX. The ground mount makes ~2% more energy. You lose ~0.4%/C. These are SunPower panels which have a very stable temperature coefficient. Poly panels would be a bit worse.