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,…

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,…

A mini-grid is an aggregation of electrical loads and one or more energy sources operating as a single system providing electricity and possibly heat, isolated from a main power grid. A modern mini-grid may include renewable- and fossil fuel-based power generation, energy storage, and load control.

From the mid-1980s to September 2003, the inflation-adjusted price of a barrel of crude oil on NYMEX was generally under US$25/barrel in 2008 dollars. During 2003, the price rose above $30, reached $60 by 11 August 2005, and peaked at $147.30 in July 2008.

Many countries and territories have installed significant solar power capacity into their electrical grids to supplement or provide an alternative to conventional energy sources. Solar power plants use one of two technologies: Photovoltaic (PV) systems use solar panels, either on rooftops or in ground-mounted solar…

An energy crisis from 2021 to 2023 began in the aftermath of the COVID-19 pandemic, resulting in shortages and increased prices in oil, gas and electricity markets. The crisis was particularly acute in Europe, and especially following the Russian invasion of Ukraine, the energy crisis became popularly associated with…

Utilita Energy is an electricity and gas supplier operating in the United Kingdom. Utilita began trading in 2003, specialising in pay-as-you-go metering.

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…

Ecotricity is a British energy company based in Stroud, Gloucestershire, specialising in selling green energy to consumers that it primarily generates from its 87.2-megawatt wind power portfolio. It is built on the principle of heavily reinvesting its profit in building more of its own green energy generation.

A power purchase agreement (PPA), or electricity power agreement, is a long-term contract between an electricity generator and a customer, usually a utility, government or company. PPAs may last anywhere between 5 and 20 years, during which time the power purchaser buys energy at a pre-negotiated price.