Natural gas is an odorless, nontoxic, gaseous mixture of hydrocarbons, predominantly methane (CH4), and accounts for nearly a quarter of the energy used in the United States. Approximately one-third of natural gas usage is for residential and commercial uses, such as heating and cooking; one-third to industrial purposes; and one-third to electric power production.
Most natural gas is drawn from wells or extracted in conjunction with crude oil production. Natural gas can also be mined from subsurface porous rock reservoirs through extraction processes. Renewable natural gas is an emerging fuel produced from decaying organic materials, such as waste from plants, landfills, wastewater, and livestock.