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Earth Energy Log
solar

kWp

Also known as: Kilowatt-peak, Watt-peak (Wp)

Nameplate DC capacity of a solar module or system measured at Standard Test Conditions.

kWp (kilowatt-peak) is the DC output capacity of a solar module or array under Standard Test Conditions (1000 W/m² irradiance, 25°C cell temperature, AM 1.5 spectrum). It is the headline number for sizing residential and commercial systems. Real-world output is always lower than kWp due to temperature, soiling, inverter losses, and shading — typically 75–85% capacity factor on the DC side.

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