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.

Solar water heating (SWH) is heating water by sunlight, using a solar thermal collector. A variety of configurations are available at varying cost to provide solutions in different climates and latitudes.

Energy is a major area of the economy of California, as it has the largest population and the largest economy in the United States. As of 2024, it is second in total energy consumption after Texas, though per capita consumption was the third-lowest in the United States partially because of the mild climate and energy…

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

According to data from the US Energy Information Administration, renewable energy accounted for 17.8% of total primary energy production and 22.7% of total utility-scale electricity generation in the United States in 2024, up from 8.4% and 21% in 2022. Since 2019, wind power has been the largest producer of renewable…

Renewable energy progress in the European Union (EU) is driven by the European Commission's 2023 revision of the Renewable Energy Directive, which raised the EU's binding renewable energy target for 2030 to at least 42.5%, up from the previous target of 32%. Effective since November 20, 2023, across all EU countries,…

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.

Water heating is a heat transfer process that uses an energy source to heat water above its initial temperature. Typical domestic uses of hot water include cooking, cleaning, bathing, and space heating.

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

On March 23, 2005, a hydrocarbon vapor cloud ignited and violently exploded at the isomerization process unit of the BP-owned oil refinery in Texas City, Texas. The explosion resulted in the death of 15 workers, 180 injuries and severe damage to the refinery.