All types of electricity generation consume water either to process the raw materials used in the facility or fuel, constructing and maintaining the plant, or to just generate the electricity itself. Renewable power sources as photovoltaic solar and wind power, which require little water to produce energy, require water in processing the raw materials to build the turbines and solar panels. If a wind turbine is mounted on a concrete or steel tower, additional tonnes of water are required in the tower's construction.