Costly conversion

There is something deeply uncomfortable about the way hydrogen- powered cars are promoted as the emerging energy economy.

Hydrogen is not an energy source but an energy vector or carrier. This means it has to be produced from one of the primary energy sources: fossil fuels, nuclear, solar, wind, biomass, hydroelectricity, and so on. All the energy we use, including hydrogen, must be produced from one of these primary energy resources.

Today, 95 per cent of hydrogen is produced from natural gas — itself a fossil fuel. To separate the hydrogen from the natural gas (methane) requires the heat energy of another fossil fuel: oil. To clean up the hydrogen, compress it, turn it into liquid fuel and sequester the CO2 by-product also requires a great deal of mechanical energy, supplied, of course, by oil.

In reality, burning a gallon of hydrogen in one of the 'zero-emissions' cars, such as the Honda FCX Clarity, produces a greater amount of emissions as burning ordinary fuel — the only difference being, SMR hydrogen production is out of sight.

Apart from that, whichever way you cut the cake, hydrogen is a costly way of converting fossil fuel into a useable energy source.

Justin Gudgeon, Berwick-upon-Tweed