Curtailment

Curtailment is a reduction in a plant’s output below what it could produce, ordered by the utility or grid operator or required by an export limit at the point of interconnection.

A power plant controller receives the curtailment order, as a setpoint in megawatts or a percentage, and reduces inverter output to meet it. For solar plus storage the battery can absorb the energy that would otherwise be curtailed and discharge it later, which is one of the main reasons to pair the two. Curtailment is also self imposed when a site’s export limit is lower than its nameplate.

Also called: Export limiting, Active power limit