Pacific Gas and Electric Company (PG&E) is an American investor-owned utility (IOU). The company is headquartered at Kaiser Center, in Oakland, California.

An energy transition (or energy system transformation) is a major structural change to energy supply and consumption in an energy system. Currently, a transition to sustainable energy is underway to limit climate change.

NRG Energy, Inc. is an American energy company, headquartered in Houston, Texas.

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.

In energy economics and ecological energetics, energy return on investment (EROI), also sometimes called energy returned on energy invested (ERoEI), is the ratio of the amount of usable energy (the exergy) delivered from a particular energy resource to the amount of exergy used to obtain that energy…

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.

Energy in Jordan describes energy and electricity production, consumption and import in Jordan. Jordan is among the highest in the world in dependency on foreign energy sources, with 92.3% of the country's energy supply being imported.