Watt-peak – Wp

The term "watt-peak" (Wp) is a unit of measurement of the maximum theoretical output of a photovoltaic panel. This value indicates the maximum power that a given PV panel can generate under standard solar conditions.

Standard solar conditions include a solar intensity of 1000 watts per square metre (1000 W/m²) and a panel temperature of 25°C. Watt-peak (Wp) is used to characterize the performance of PV panels under optimal conditions.

It is important to emphasize that the value of Wp is a theoretical maximum and is only achieved under ideal conditions, which can rarely be achieved in practice. Various factors such as shading, panel inclination, temperature inversion or impurities on the panels can actually affect the performance of the panels and cause the achieved performance to be lower than the Wp value.

However, the Wp value is an important measure when evaluating and comparing different types of PV panels and when planning PV systems, as it allows to determine what theoretical performance can be expected under optimal solar conditions.