The myths of hydrogen as a fuel source
Hydrogen or EVs (from EV World)
Both government and industry need to come to terms with reality of hydrogen, according to David Strahan, the author of The Last Oil Shock: A Survival Guide to the Imminent Extinction of Petroleum Man. Writing in today's edition of ODAC Newsletter, he points out the short-term focus of current hydrogen infrastructure initiatives like the one in the UK that saw the opening of the first public hydrogen refueling station at Birmingham University, to be followed by three more in London. He notes they will be supplied by hydrogen derived from natural gas, which still emits CO2 and is a finite resource. He then tackles the issue of creating it from electrolyzed water and makes some sobering comparisons.
- To produce the gas cleanly and in bulk you must electrolyze water, which requires huge amounts of power. (To give an idea of scale, two chlorine plants operated in Cheshire by Ineos Chlor, which produce the chemical by electrolyzing salt water, consume more electricity than the entire city of Liverpool).
- Then, to reduce the hydrogen gas to a manageable volume, it must either be chilled to -160C to become liquid, or must be compressed, both of which processes require more energy.
- Because of all this, to run Britain's road transport on cleanly generated hydrogen would require a massive expansion of electricity generating capacity: 42 Sizewell B nuclear power stations (we currently have the equivalent of 10); solar panels covering every inch of Lincolnshire; or a wind farm covering the entire northwest region of England. You would be much better off developing electric vehicles, where the energy losses between wind turbine and tarmac are massively smaller. It is mystifying therefore that so many apparently intelligent people remain transfixed by the hydrogen mirage.
- It is often stated that hydrogen
explosions cannot occur in the open air. On
3 March 1983 there was a hydrogen explosion in an open street, called
in Stockholm, Sweden. The event occurred when gas cylinders where
unloaded from a lorry and hydrogen suddenly started to leak out. The
hydrogen was in 18 cylinders
containing about 10 kg of hydrogen. The blast wave from the explosion
broke windows in a range of about 90
meters, causing 16 persons to be injured. Note that the quantity of
here is about 1/3 the quantity that would be needed to give a car an
In short the use of Hydrogen is a net energy loss (at every stage), from production and storage, to transportation, distribution and eventual use in electric vehicles. It is much more efficient to generate electricity with Wind or PV power, and store it in batteries, (which are an existing and rapidly improving technology), for use in electric vehicles.
Breaking a hydrogen molecule into electrons and protons, and then sending it through an electric drive motor, and recombining the particles with oxygen to produce water poses an enormous challenge. "While hydrogen is universally abundant, it's not cheap to get at", noted the Washington Times editorial. "At the moment, fuel cells are actually energy losers, since it costs more to free the hydrogen than is earned by running hydrogen through fuel cells." In brief, it costs more energy to turn hydrogen into energy than current technology would permit.
The process involved is called hydrolysis, popularly called "cracking water. To do this you need energy, usually from coal, natural gas or nuclear plants. Since (once extracted) hydrogen has a very low energy density. It would cost more to fuel your car with it than our current system. The energy density of hydrogen is about one-tenth that of natural gas. While hybrid engines, available only in "demonstration" vehicles, would reduce our dependency on imported oil, that does not, however, make it any less of a bad idea.