Photovoltaics are the best known method for converting solar energy to electrical energy. Which of the following units acts as a measure for photovoltaic power capacity?

Photovoltaics are the best known method for generating electric power by using solar cells to convert energy from the sun into a flow of electrons. The photovoltaic effect refers to photons of light exciting electrons into a higher state of energy, allowing them to act as charge carriers for an electric current. Photovoltaic power capacity is measured as maximum power output under standardized test conditions (STC) in Wp (Watts peak).