Photovoltaic power stations are typically rated in terms of the DC peak capacity of the solar arrays, in mega watt-peak (MWP), or of the nominal maximum AC output in megawatts (MW) or mega volt-amperes (MVA). Most solar parks are developed at a scale of at least 1 MWP. The largest operating photovoltaic power stations have capacities of hundreds of MWP; projects up to 1 GWP are planned.
Most of the existing large-scale photovoltaic power stations are owned and operated by independent power producers, but the involvement of community- and utility-owned projects is increasing. To date, almost all have been supported at least in part by regulatory incentives such as feed-in tariffs or tax credits, but capital costs have fallen significantly in the last decade and are expected to progressively reach grid parity, when external incentives may no longer be required.