Natural gas vehicle gas has the highest energy/carbon ratio of any fossil fuel, and thus produces less carbon dioxide per unit of energy. The major difficulty in the use of natural gas is transportation. Natural gas pipelines are economical and common on land and across medium-length stretches of water (like Langeled, Interconnector and Trans-Mediterranean Pipeline), but are impractical across large oceans. Liquefied natural gas (LNG) tanker ships, railway tankers, and tank trucks are also used. CNG is typically stored in steel or composite containers at high pressure (3000 to 4000 psi, or 205 to 275 bar). These containers are not typically temperature controlled,
Liquefied natural gas efficiency combined cycle power stations. For an equivalent amount of heat, burning natural gas produces about 30 percent less carbon dioxide than burning petroleum and about 45 per cent less than burning coal. On a per kilometre transported basis, emissions from LNG are lower than piped natural gas, which is a particular issue in Europe, where significant amounts of gas are piped several thousand kilometres from Russia. However, emissions from natural gas transported as LNG are higher than for natural gas produced locally to the point of combustion as emissions associated with transport are lower for the latter. However, on