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,…
SolarCity
SolarCity Corporation was a publicly traded company headquartered in Fremont, California, that sold and installed solar energy generation systems as well as other related products and services to residential, commercial, and industrial customers. The company was founded on July 4, 2006, by Peter and Lyndon Rive, the…
Passive solar building design
In passive solar building design, windows, walls, and floors are made to collect, store, reflect, and distribute solar energy, in the form of heat in the winter and reject solar heat in the summer. This is called passive solar design because, unlike active solar heating systems, it does not involve the use of…
Solar cell
A solar cell, also known as a photovoltaic cell (PV cell), is an electronic device that converts the energy of light directly into electricity by using the photovoltaic effect. It is a type of photoelectric cell, a device whose electrical characteristics (such as current, voltage, or resistance) vary when it is…
1979 oil crisis
The 1979 oil crisis, sometimes referred to as the second oil crisis (in reference to the 1973 oil crisis), refers to the drop in oil production in the aftermath of the Iranian Revolution that led to an energy crisis in 1979. Although the global oil supply only decreased by approximately four percent, the oil markets'…
APsystems
Altenergy Power System better known as APsystems (formerly APS) is a global technology company that operates in the renewable energy space. APsystems is a provider of multi-platform module-level power electronics (MLPE) solutions for the solar photovoltaic (PV) industry.
List of photovoltaics companies
This is a list of notable photovoltaics (PV) companies. Grid-connected solar photovoltaics (PV) is the fastest growing energy technology in the world, growing from a cumulative installed capacity of 7.7 GW in 2007, to 320 GW in 2016.
Distributed generation
Distributed generation, also distributed energy, on-site generation (OSG), or district/decentralized energy, is electrical generation and storage performed by a variety of small, grid-connected or distribution system-connected devices referred to as distributed energy resources (DER). Conventional power stations, such…
Solar power in Switzerland
Solar power in Switzerland has demonstrated consistent capacity growth since the early 2010s, influenced by government subsidy mechanisms such as the implementation of the feed-in tariff in 2009 and the enactment of the revised Energy Act in 2018. In 2025, solar power contributes nearly to 8 TWh of generation to the…
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.