Renewable energy in California
California produces more renewable energy than any other state in the United States except Texas. In 2018, California ranked first in the nation as a producer of electricity from solar, geothermal, and biomass resources and fourth in the nation in conventional hydroelectric power generation.
Grid energy storage
Grid energy storage, also known as large-scale energy storage, is a set of technologies connected to the electrical power grid that store energy for later use. These systems help balance supply and demand by storing excess electricity from variable renewables such as solar and inflexible sources like nuclear power,…
Variable renewable energy
Variable renewable energy (VRE) or intermittent renewable energy sources (IRES) are renewable energy sources that are not dispatchable (adjustable on demand) due to their fluctuating nature, such as wind power and solar power, as opposed to controllable renewable energy sources, such as dammed hydroelectricity or…
Energy policy of Canada
Canada has access to all main sources of energy including oil and gas, coal, hydropower, biomass, solar, geothermal, wind, marine and nuclear. It is the world's second largest producer of uranium, third largest producer of hydro-electricity, fifth largest natural gas producer, and the fifth largest producer of crude…
Grupo Opaia SA
Grupo Opaia SA is a holding company operating under Angolan law based in Luanda, Angola, running projects in civil construction services, solar energy technology, drinking water systems, hotel service and tourism, agriculture, finance and more. It was founded by the Angolan Agostinho Kapaia, from Huambo, in 2002.
Feed-in tariffs in the United Kingdom
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…
Energy in the United States
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 in India
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
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.
Solar power in Spain
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.