FOR millions of Britons the morning starts with the whine of an electric
milk float, followed by the clink of glass as the daily pinta drops on the
doorstep. But despite having Europe鈥檚 largest fleet of electric vehicles, almost
all the traffic on the roads uses either diesel or petrol.
AEA Technology鈥檚 Energy Technology Support Unit, based in Harwell,
Oxfordshire, has spent the past two years analysing the emissions and fuel
efficiency of alternatives to petrol and diesel. In a report published last
week, it concludes that there is no complete alternative to petrol and diesel
鈥渇or the foreseeable future鈥�. However, there may be scope for cutting emissions
by using alternative fuels to power certain types of vehicles, notably buses and
delivery vans.
The report singles out the potential of electric vehicles. It says that
because they have limited range and performance they are best suited for use in
urban areas. 鈥淚f the objective is to improve air quality in cities, perhaps
electric vehicles are the way forward,鈥� says Simon Collings of ETSU.
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The study looked at the emissions from eight different fuels鈥攆rom the
start of the fuel production process through to the point where they emerge from
the exhaust pipe. Most of the alternative fuels have their drawbacks. Biodiesel,
for example, can be made from rapeseed oil and burnt in any diesel engine.
However, even if all the set-aside land in Britain were converted to producing
biodiesel it would still produce less than 7 per cent of the diesel used by the
country鈥檚 vehicles.
Fuels such as methanol, ethanol, compressed natural gas (CNG) and liquefied
petroleum gas (LPG) offer no clearcut advantages. Compressed natural gas, for
example, is the best fuel for cutting emissions of nitrogen oxides, but the
worst for producing hydrocarbons. 鈥淚f you are concerned about global warming
they don鈥檛 offer any amazing advantages at all,鈥� says Collings. 鈥淎 10 per cent
or so difference is not going to solve the warming problem.鈥�
The House of Lords select committee on science and technology last week began
an inquiry into the development of technologies that would cut the environmental
damage caused by vehicles, while allowing people to keep driving their cars. The
committee heard evidence last week from the Department of Transport, which
commissioned the ETSU report.