Biodiesel
Biodiesel is produced from vegetable oil crops such as rape seed or from the conversion of waste materials such as cooking oil.  It can be mixed with conventional diesel up to 5%.  Biodiesel is already sold in the UK at a small number of Tesco filling stations and branded as GlobalDiesel

Electricity
The efficiency of electricity depends on the source from which it is derived. New technology in solar, tidal and wind power may offer potential for the future. However, electricity generated from non-renewable sources such as coal or natural gas is both inefficient and not sustainable. Electric vehicles produce less noise pollution and zero tail pipe emissions.  If a suitable renewable source of electricity could be found, they offer potential for the future.

Hydrogen
Most major car companies are working on hydrogen models which emit very low amounts of exhaust gas and almost no CO2. Some hydrogen vehicles are already on the road.  However, there are still many technical difficulties to be overcome - large infrastructure changes and storage tanks are needed with complex and unusual ventilation systems.  It is generally believed that hydrogen cars are still at least 20 years away from general use.

Conclusion
It is our belief that there is no one fuel which provides all of the answers to carbon emissions problems and the most realistic approach is to introduce the fuels which are available now eg bioethanol and biodiesel.  Work towards incorporating them into longer term solutions will create a sustainable future solution for transport fuel.  Hybrid cars of the future could run on a combination of electricty, biofuels and hydrogen.