Solar Module Comparison

Updated February 22, 2023

Many things have changed in the last decade of solar power. 

Terminology: 

P/M = polycrystalline or monocrystalline. Almost no modern panels are poly these days, so this distinction is no longer relevant.

Area = area of solar module on a square foot basis. Usually corresponds with weight.

STC = standard testing conditions. Manufacturers internally test their own solar modules. STC specifies a temperature of 25°C (77 F), solar irradiance of 1000 W/m2 and an air mass 1.5 (AM1.5) spectrums. These are "perfect" lab conditions, you will very rarely see a panel meet these output specs in the real world

PTC = PV USA Test Conditions.The PTC rating is an independent measure of a module's efficiency. PTC ratings are 1,000 watts/m2, 20 degrees ºC (68ºF), and wind speeds of 1 meter per second at 10 meters above ground level. These values are more in line with "real world" output at peak solar times and locations.

PTC/STC = this value represents the approximate energy output comparing the STC (name plated output) to the PTC tested conditions. In general, the higher the percentage the total energy output will be higher

Pwr Tol = power tolerance of solar modules, modules will perform based on tolerance value ± STC value