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.

A feed-in tariff (FIT, FiT, standard offer contract, advanced renewable tariff, or renewable energy payments) is a policy mechanism designed to accelerate investment in renewable energy technologies by offering long-term contracts to renewable energy producers. This means promising renewable energy producers an…

The availability and uptake of green electricity in the United Kingdom has increased in the 21st century. There are a number of suppliers offering green electricity in the United Kingdom.

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'…

Building insulation materials are the building materials that form the thermal envelope of a building or otherwise reduce heat transfer. Insulation may be categorized by its composition (natural or synthetic materials), form (batts, blankets, loose-fill, spray foam, and panels), structural contribution (insulating…

Solar power includes solar farms as well as local distributed generation, mostly on rooftops and increasingly from community solar arrays. In 2025, utility-scale solar power generated 295.7 terawatt-hours (TWh) in the United States.

Electricity pricing (also referred to as electricity tariffs or the price of electricity) can vary widely by country or by locality within a country. Electricity prices are dependent on many factors, such as the price of power generation, government taxes or subsidies, CO2 taxes, local weather patterns, transmission…

Solar power is a major contributor to electricity supply in Australia. As of December 2025, Australia's over 4.29 million solar PV installations had a combined capacity of 45.1 GW photovoltaic (PV) solar power.

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.

A liquid-crystal display (LCD) is a flat-panel display or other electronically modulated optical device that uses the light-modulating properties of liquid crystals combined with polarizers to display information. Liquid crystals do not emit light directly but instead use a backlight or reflector to produce images in…