I congratulate my hon. Friend the Member for Devon, North (Mr. Speller) on obtaining this debate, because he has made a stimulating contribution on a subject of which many hon. Members are blissfully ignorant. I am sure that in the years to come many people will read his speech and will say that, as chairman of the all-party alternative energy group, he has yet again made a valuable contribution. Certainly gas-powered vehicles are an interesting subject and one that we must take seriously in our search for more environment-friendly road transport.

At present, the Government are targeting vehicle emissions. We are successfully encouraging the use of unleaded fuel and we have recently agreed in the European Community, tough emission standards for all types of new car which will take effect from the end of next year. We are now seeking much tighter standards for lorries. Later this year we shall introduce a totally new emissions check into the MOT test to encourage people to keep their engines in tune.

Alternative fuels are a good example of an area where one needs to consider the trade-off between the advantages and the disadvantages. Solving one environmental problem by switching from one fuel to another can often create another—or there may be an economic penalty. The objective must be to get the balance right in each case. So what role do we see for alternative fuels?

A very wide range of alternative fuels is in principle possible, but there are no panaceas. It is necessary to consider not only the environmental benefits but other factors, such as the practicality of the fuel for road vehicle use, availability, refuelling and supply infrastructure and cost. The possibilities include LPG, natural gas, electricity and hydrogen, among others. Some of those are already in use to a limited extent in some countries—for example, natural gas in New Zealand and electric vehicles in this country, where by world standards we have a large fleet of electric vehicles. Others, such as hydrogen, are at the experimental stage.

The Government recognised many years ago the benefits of natural gas as a clean, convenient fuel for domestic and industrial use. Since the exploitation of resources in the North sea began in the early 1960s, gas production has increased steadily. In 1989, 45 billion cu m was being produced from 28 offshore gas fields and one onshore field, at a value of about £2·1 billion. Four new offshore fields began production in 1989. There are reserves of between 560 and 1,770 billion cu m, which is estimated to be between 10 and 30 years' consumption at the current rate of 55 billion cu m per year.

Recently, concerns about global warming have focused attention on the use of fuels such as natural gas instead of the conventional fossil fuels, oil and coal. These fuels have low carbon-to-hydrogen ratios and produce less carbon dioxide, the principal greenhouse gas.

The successor companies to the Central Electricity Generating Board—PowerGen and National Power—are considering projects to generate electricity from natural gas using energy-efficient combined cycles of gas and steam turbines. A number of other companies are making similar plans in competition with PowerGen and National Power.

As my hon. Friend will know, the Road Vehicles (Construction and Use) regulations permit the use of gas as a fuel for road vehicles, but the only type of gas allowed by the regulations at present is liquefied petroleum gas. This can be stored in liquid form at comparatively low pressures—about 250 psi—and has been used as a fuel in motor vehicles for many years, but not in large quantities, at least in this country.

The use of any other gaseous fuel in road vehicles is prohibited by the regulations. This is because the detailed requirements cater only for gases at the sort of pressure found in LPG systems.