Yes, at 150 degrees F or so, power output can drop 20%.
The power drop is 0.5% per degree C.
So, building a system to lower the temperature is a good thing!
With that said, what will it cost to build a system to lower the temp 70 some degrees? Or even lower, must stay above the due point. Power gets better colder.
Lest say you have 10 free air panels, they get heated to 150'F.
At 70'F you get the same power out with 8 panels, save the cost of two panels.
What will the equipment to cool the 8 panels cost? How much power does it need?
Every system I have seen or devised cost more than the cost of two additional panels.
If you have a cold water stream near by, that may be worth considering.
The same thing applies to trackers, I thought they were great. Until I looked at the cost
I may be able to build my own tracker for a lower cost, but for all the work I may not do it. I have seen some simple single axis trackers. Manually change second axis.
Power voltage tracking: the cost is below the cost of the replacement panels therefore, it's worth doing.
If the solution is break even, then you have to consider other benefits, time etc.
I have looked into using films in front of the solar panel. The film claimed 85% visible light transmission with 80% heat reflection. (not sure if the heat is right).
The film by itself was not cost effective. 85% light = 85% power, the temperature would have to stay below 90'F to brake even. I did not think it would. Ambient temp is almost that high. With the 20% heat that gets through, not good.
I figured if I used Mirrors to increase the light to 2x...
Please understand, generally when using mirrors a tracker is required.
Since I needed a tracker I could shape the solar panels to reflect the heat back to a single point heating a sterling engine (we are thinking big here). The sterling engine would be operated to cool the solar panels. The interesting thing about the heat is it produced more power than the solar panel! I started loosing interest in solar electric panels. Maybe consider the heat engine.
I searched and found a solar cell designed for 350 suns., yes 350 suns! rated to 1000 suns, the efficiency dropped above 350 suns. Was a three junction solar cell, efficiency was 32% at 350 suns. Normal panels are around 12-15%. Been three years, military is buying all they can produce for a huge price, dropped any plans to use them.
Last year found a two junction solar cell, 21% at 30 suns. Just as costly.
Normal solar panels if used with mirrors will void the warranties. The solar cells all required 25'C temperature. How do you keep a solar cell at 25'C with 350 suns?
Keep thinking up ideas. And remember:
Have fun.