kW / Kilowatt

A kilowatt, or kW, is a unit of power equal to 1,000 watts. It describes the rate at which electricity is being used, generated, charged or discharged at a particular moment rather than the total amount of energy used over time. In home energy documents, kW can describe the output of an EV charge point, the AC output limit of an inverter, a battery’s charge or discharge power, the electrical demand of a heat pump or the live import and export shown by a monitor. The distinction from kWh matters because a 5 kW load running briefly does not use 5 kWh; it uses energy according to how long that power level is sustained. A 1 kW load running for one hour uses 1 kWh, before any equipment losses or measurement differences.