CNG stands for Compressed Natural Gas and is the most widely used technique to store natural gas in vehicles. With CNG natural gas is compressed to about 1 percent of its volume. It is subsequently distributed to filling stations from where it can be easily transferred to natural gas vehicles and used as fuel.
CNG is commonly used by passenger cars, which on average store around 20 kilograms of CNG (natural gas as a fuel is measured in kilograms, 1 kg of gas has about the same energy value as 1,4 liters of diesel). This gives a typical car a driving range of about 400 kilometers. CNG is however also used in vans, buses and trucks, particularly in urban areas where distances to refuelling points are relatively short. Many city buses for example are fuelled by CNG, benefitting from the extremely low emissions from natural gas vehicles of particulate matter and nitrogen oxides or NOx, substantially reducing air pollution and contributing significantly to a much healthier urban environment. CNG is increasingly offered as bio CNG with varying percentages of biomethane in the gas mix.