A feed-in tariff (FIT) is paid by energy suppliers in the United Kingdom if a property or organisation generates their own electricity using technology such as solar panels or wind turbines and feeds any surplus back to the grid. The FIT scheme was imposed on suppliers by the UK government, and applied to…

A rooftop solar power system, or rooftop PV system, is a photovoltaic (PV) system that has its electricity-generating solar panels mounted on the rooftop of a residential or commercial building or structure. The various components of such a system include photovoltaic modules, mounting systems, cables, solar inverters…

Energy in the United States is obtained from a variety of sources, although the majority came from fossil fuels in 2025: 37% of the nation's energy originated from petroleum, 36% from natural gas, and 9% from coal. Electricity from nuclear power supplied 9% and renewable energy supplied 9%, which includes biomass,…

Solar power is an important source of electricity in India. Since the mid-2010s, India has increased its solar power significantly with the help of various government initiatives.

Solar water heating (SWH) is heating water by sunlight, using a solar thermal collector. A variety of configurations are available at varying cost to provide solutions in different climates and latitudes.

Spain is one of the first countries to deploy large-scale solar photovoltaics, and is the world leader in concentrated solar power (CSP) production. Spain is also one of the European countries with the most hours of sunshine.

A solar inverter or photovoltaic (PV) inverter is a type of power inverter which converts the variable direct current (DC) output of a photovoltaic solar panel into a utility frequency alternating current (AC) that can be fed into a commercial electrical grid or used by a local, off-grid electrical network. It is a…

Solar power has a growing role in electricity production in the United Kingdom, contributing around 6.4% of the UK's annual power generation in 2025. As of 2025, on sunny days, it provides over 30% of the UK's power consumption at times.

Polycrystalline silicon, or multicrystalline silicon, also called polysilicon, poly-Si, or mc-Si, is a high-purity, polycrystalline form of silicon, used as a raw material by the solar photovoltaic and electronics industry. Polysilicon is produced from metallurgical grade silicon by a chemical purification process,…

Geothermal energy is thermal energy extracted from the Earth's crust. It combines energy from the planet's formation and from radioactive decay.