There are a few different types of renewable energy sources in which could all be greener to the environment for use in our transport around the world.

Petrol/Electric Hybrid

These vehicles utilise the existing infrastructure of a small internal combustion engine, in unisen with an electric engine. There are two ways these petrol/electric hybrids are run, one is in parallel, the other is in series. In a parellel setup, either the electric motor or the petrol engine can drive the car, either individually, or at simultaneously. In a series setup, the petrol engine drives a generator, in turn the generator either recharges the batteries, or sends power to the electric motor to move the vehicle.

Two companies are leading the way in petrol/electric hybrid vehicle development, namely Toyota and Honda with their Prius (Figure 2) and Civic cars, respectively. Fuel consumption is doubled to around 4.0L/100km 1 2, and CO₂ emissions are reduced around 40%.

Hydrogen Internal Combustion

The hydrogen internal combustion engine is quite simple actually, it is run exactly the same as a petrol internal combustion engine, but instead of fuel being used as the charge, hydrogen is used and combusted. This seems to be one of the best ideas for the future of automotive vehicles for enthusiasts, as you will still get the same noise, vibration, power application as a normal petrol engine, but in green form.

Hydrogen Fuel Cell

Fuel Cells produce electricity electrochemically by using a the supply of fuel (hydrogen in this case) and an oxidant (in this case oxygen). The cell works by seperating the electrons and protons of the hydrogen and forcing the electrons to travel through an electric circuit, thus creating current.