Also known as nameplate capacity or capacity. The maximum amount of electricity that a generating station (also known as a power plant) can produce under specific conditions designated by the manufacturer. Installed capacity is typically calculated in megawatts (MW). For example, in the first quarter of 2012, there was 1,695 MW of new wind energy installed capacity in the US for a total of 48,611 MW of cumulative wind installed capacity.

Installed capacity is higher than the amount of electricity that a power plant can actually produce because it does not take into account factors that can reduce electricity production, including:

For more information on installed capacity and renewable energy generally, see Practice Note, Renewable Energy: Overview (US).