Active power

Active power, also called real power, is the part of AC power that actually does work. It is measured in watts. Inverters, battery inverters and monitoring platforms usually show active power in kW, for example for the utility grid, a generator, an external source or the loads. The nameplate active power rating of a DER is the active power rating in watts at unity power factor. Inverters also have a nominal maximum value that caps the active power at their output. Inverters and battery systems can reduce active power on command, as a percentage of rated maximum power or of nameplate maximum real power. Grid support modes can also change active power with grid voltage (Volt-Watt, P(V)) or with grid frequency (Frequency-Watt, P(f)). In battery-backup systems, the PV inverters must be able to control their active power according to frequency. Active power is separate from reactive power, which monitoring tables list in kVAr, and inverters provide separate control modes for each.

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• sentence 1: support check: partial - The passages say active power is in watts and mention real power, but not that it is the part of AC power that does work.
• sentence 1: review: partial - The passages back 'active power in watts' and use 'real power' for the same quantity, but none says active power is the part of AC power that does work. -->