STC rating to operating-condition power

Enter the datasheet STC power, Pmax coefficient and NMOT, then your own irradiance and ambient temperature. Use a decimal point or comma and a minus sign for negatives. Defaults are the Qcells 425 W datasheet and an invented hot day. A design aid, not a yield guarantee.

Module STC power, W

Modules in the array

Pmax temperature coefficient, %/K

NMOT from the datasheet, °C

Irradiance on the module, W/m²

Ambient air temperature, °C

Cell temperature: - °C

Module power: - W (- of STC)

Array DC power: - kW against - kWp at STC

Cell temperature = ambient + (NMOT - 20) x irradiance / 800. Power = STC power x irradiance / 1,000 x (1 + coefficient x (cell - 25)). Before wiring, mismatch, soiling and inverter losses.