Photovoltaics individual cells are wired together and encapsulated in a panel groups of PV panels installed on a building are called an array silicon PV is typically 12% efficient so an incident solar intensity of 600W/m 2 falling on a 1m2 panel will generate 72W typical energy yields are ~100kWh/m 2 /yr conversion efficiency is dependent upon: –the PV material used –temperature –solar intensity –the load