Natural gas Natural gas Natural gas is a naturally occurring hydrocarbon gas mixture consisting primarily of methane, but commonly including varying amounts of other higher alkanes, and sometimes a small percentage of carbon dioxide, nitrogen, hydrogen sulfide, or helium. It is formed when layers of decomposing plant and animal matter are exposed to intense heat and pressure under the surface of the Earth over millions of years. The energy that the plants originally obtained from the sun is stored in the form of chemical bonds in the gas. Natural gas is a fossil fuel used as a source of energy for heating,
Natural gas etc.). Quantities of natural gas are measured in normal cubic meters (cubic meter of gas at "normal" temperature and pressure ) or standard cubic feet (cubic foot of gas at "standard" temperature and pressure ), . The gross heat of combustion of commercial quality natural gas is around , but this can vary by several percent. This is about (assuming a density of , an approximate value). Gas prices for end users vary greatly across the EU. A single European energy market, one of the key objectives of the EU, should level the prices of gas in all EU member