How do companies make standard PV measurements anyway?
There are ISO standards for some PV measurements, but as far as I can tell the American standards formulated by the ASTM (American Society of Testing and Materials) are the most widely used. “Good light sources for this type measurement are extremely expensive and can take a tremendous amount of space, and it’s quite common for people without the money or space to use less expensive light sources that aren’t quite as good. For that reason, there’s no “typical” or “standard” setup. When making standard measurements of the sort that appear in module specifications, though, here’s what you’re going for: • “Light intensity of 1000 W/m^2, uniform over the active area of the module and shining at a normal angle to the module surface. • “Solar spectrum at air mass 1.5 (AM1.5); that is, sunlight from space after it has passed through the atmosphere 1.5 times (or once at a 48 degree angle from vertical). • “Module temperature of 25 C. “Typically, none of these parameters is dead on and the resu
