Renewable energy (also called green energy) is energy made from renewable natural resources that are replenished on a human timescale. The most widely used renewable energy types are solar energy, wind power, bioenergy/biomass, and hydropower.

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

Open energy-system models are energy-system models that are open source. These models can also be known as open energy models or open-source energy-system models or some combination thereof.

Octopus Energy Group Limited (formerly Octopus Energy Limited and Octopus Energy Holdings Limited), known as Octopus Energy, is a British company operating in the fields of energy generation and supply. It was founded in 2015 with the backing of Octopus Group, a British asset management company.

O.Y. Nofar Energy Ltd., commonly known as Nofar Energy (Hebrew: ע.י. נופר אנרג'י בע"מ), is an Israeli renewable energy company headquartered in Kfar Saba.

The Energy Saving Trust Recommended logo was a UK-based labelling and certification scheme for energy efficient products. A product that displays the logo shows that it met strict criteria on energy saving.

Good Energy Group PLC is a British energy company based in Chippenham, Wiltshire that provides services in the electrification of transport and decentralised renewable energy generation such as domestic solar panels. The company is also an energy retailer, and built a portfolio of wind and solar generation which was…

Renewable energy in the United Kingdom refers to energy from renewable sources used for electricity generation, heat and transport in the United Kingdom. In 2024, renewables accounted for 50.4% of UK electricity generation and 16.2% of gross final energy consumption.

Renewable energy commercialization involves the deployment of three generations of renewable energy technologies dating back more than 100 years. First-generation technologies, which are already mature and economically competitive, include biomass, hydroelectricity, geothermal power and heat.

The Association for Decentralised Energy (ADE), formerly the Combined Heat and Power Association, is a trade association that supports the growth of decentralised energy systems, such as district heating systems. The association is based in London.