Photovoltaics (PV): It transform light directly into electricity. The typical current residential installation of 12m2 could produce around 1,300 kWh pa with a peak of around 1.9kW, though larger and more efficient installations are possible. Different materials can be used to give different efficiencies, with amorphous silicon efficiencies around 4-6% and crystalline efficiencies at around 15% and potentially up to 20%. The outcome from PV depends on the specific installation: shading can decrease output severely and orientation is as well important.