Economics

As with other alternative fuel vehicles, NGVs are characterised by higher capital costs but lower fuel costs. Compared with a petrol car the NGV is approx. 3.000 Euro more expensive, compared with a diesel car approx. 800 Euro. But with 20.000 km travelled in one year the NGV amortizes in 4 years. Many gas suppliers or countries grant financial subsidies when buying a NGV. Please have a look at “Country specific facts and developments”.

NGV refuelling stations are expensive and are only commercially viable if they refuel a relatively largely number of vehicles. Therefore the market penetration of NGVs suffers from the classic problem, that fuel suppliers are reluctant to construct refuelling stations until there are sufficient numbers of NGVs and operators are unwilling to purchase the vehicles until there are sufficient refuelling stations.

Safety

The fuel storage cylinders used in NGVs are much stronger than petrol fuel tanks. The design of NGV cylinders are subjected to a number of federally required " severe abuse" tests, such as heat and pressure extremes, gunfire, collisions and fires.

NGV fuel systems are "sealed," which prevents any spills or evaporative losses. Even if a leak were to occur in an NGV fuel system, the natural gas would dissipate up into the air because it is lighter than air. It also has a narrow range of flammability, that is, in concentrations in air below about 5 percent and above about 15 percent, natural gas will not burn. The high ignition temperature and limited flammability range make accidental ignition or combustion of natural gas unlikely.

Natural gas is not toxic or corrosive and will not contaminate ground water.

(Source: NGV America and TREATISE: Cleaner Fuels & Vehicles)