High Temperature Solar Module Performance
I had someone ask a question about how solar modules perform when they get hot. Solar modules are less efficient when they are hot. Every module has a temperature coefficient of Power Max (Pmax). The CEC supplied a list of modules and their Temperature Coefficients. Here are a few examples.
Module %/K
Sanyo HIP-195BA3 -0.317
Sunpower SPR-205-BLK-U -0.387
SolarWorld SW 175 mono/P -0.47
Mitsubishi PV-MF170EB4 -0.471
Kyocera KC200GT -0.48
Evergreen ES-195-SL -0.486
Kyocera KD210GX-LP -0.49
Sharp ND-208U2 -0.495
What does this mean.
Well if Pmax is at 25 degrees C and a really hot hot roof gets up to 90 degrees C, then there is a 55 degrees C....Or degree K (Kelvin) differential.
55 degrees C x -0.317 equals 17.4% power loss for Sanyo HIP-195BA3s at high temperature
55 degrees C x -0.495 equals 27.2% power loss for Sharp ND-208U2s at high temperature
That is a 9.8 percent difference in power loss at high temperature. Generally, high temperature would occur when the sun is at it's most intense and power losses would be most significant.
All systems are not created equally. It really doesn't matter how big the system is in kilowatts (kW). What is much more important is how much power it produces in kWhs over time.
