Temperature fluctuation

[gardenia]

From the scientific point of view, why is it important that the solar panels are resistant to temperature fluctuations?

 

[Worcester]

Voltage Output and hence power will vary, as the temperature goes up the output goes down. Just download the data sheet of any panel and you'll either see a % per degree C or a mV/DegreeC figure quoted

 

[FB.]

Yes, the output of solar panels can drop by 10% from their nominal rating in hot summer weather.

This temperature de-rating is made doubly worse on calm days when there is no breeze to help cool the panels.

My 3.7kW system struggled to get above 3kW during the summer (July-August), yet was able to reach full power in late spring (April-May) and again in early autumn (September).

The effect of temperature is less when their are lots of small clouds in the sky, as their periodic blocking of the sun gives the solar panels a few minutes to cool; resulting in a boost to performance for a few minutes once the cloud ceases to block the sun. After a few minutes back in the sun, the panels are hot again and power output drops again........something like this:

Full sun: 3kW (panels hot)

White cloud blocks sun: 1kW (panels cool, but also reduced light shining on them)

Back to full sun: 3.6kW

After a couple of minutes: 3.3kW (panels warming again)

After several minutes: 3kW (panels hot again)