2 Alternative sources of energy

2.1 Hydrogen

Hydrogen can be used as a fuel in a fuel cell to produce electricity and heat with high efficiency and no emissions. It can also be burnt as a fuel, again with relatively no harmful emissions apart from a small amount of nitrous oxide.

However, hydrogen has to be produced, as it cannot be simply extracted from the ground like oil or natural gas. Hydrogen as an energy source is a secondary source like electricity. It has to be produced using other sources of energy; but when created it is a useful carrier of energy.

The options for producing hydrogen include:

• reforming fossil fuels, allowing the carbon to be captured and stored (see other steps on carbon capture)

• by electrolysis using electricity from renewable energy sources

• by electrolysis using electricity from nuclear plant.

One problem is generating the hydrogen. In an ideal hydrogen future we would use renewable energy to generate the hydrogen, which can then be used for space heating (replacing natural gas) or for transport (replacing oil). Clearly, currently we do not have enough renewable energy to contemplate this. One option might be to use fossil fuels like coal to generate the hydrogen, providing that carbon capture and sequestration techniques are used to minimise the atmospheric CO₂ emissions. Alternatively, nuclear energy could be used to generate the hydrogen.

Once produced, the hydrogen needs to be transported and stored, and this requires new technologies to be developed. The use in vehicles also needs new technologies that are not yet commercially available. The downside is that energy needs to be used to provide the hydrogen.