
Hydrogen is a hotly touted energy source for many, and a form of energy to be cautioned away from for others. It is, however, the focus of quite substantial current development and spending. Hydrogen also has a unique place in the public imagination following its place in the futurism schematics of past decades; put forward as a fuel for for cars and transportation machines, many of us will remember the story of the hydrogen powered car that ‘the corporations won’t let us have’.
Hydrogen (H) is produced from water (H20); when the hydrogen is combined with oxygen (O), it produces energy.
The hydrogen must first be produced from water, then, before it can be used as a fuel. Electrolosis of water is one method of ‘getting the hydrogen out’ of the water; it is paramount that the energy used for the electrolosis process is kept at a low level in order for the whole enterprise to be worthwhile (i.e., so that it isn’t the case that more energy is spent than is gained); the energy used for this electrolosis should also be of a renewable kind, from a green source. Hydrogen, produced in this way, could then be a viable alternative to fossil fuels. But done wrongly, more energy will be spent producing the hydrogen than is gained when the hydrogen is eventually used as a fuel; and if the energy used to produce the hydrogen is from ‘dirty’ fossil fuels, then the whole enterprise starts to look pretty un-green.
Those who wish to promote hydrogen as a fuel of choice in a future green energy economy point to its ‘clean’ nature when used a fuel for cars or engines; there is no volatile, noxeous or pollutive gases in its exhaust, and instead, only water vapour is released. The controversy arises instead from the energy used in its creation and transportation as a fuel- this is where the current development process needs to iron out the problems. One possible option to aleviate carbon dioxide (CO2) emissions in the production of hydrogen is to have carbon capture or carbon sequestration used where the hydrogen is produced: carbon capture, however, is a controversial issue in many people’s books, and hasn’t been resolved satifactorily for everyone. It seems rather a bad and wasteful idea to pump out CO2 willy nilly, with the hope of this gas being ‘captured’.
The use of renewable energy to produce hydrogen from water is a way out of the fossil fuel method of production. A hybrid of hydrogen power with wind or solar is a hopeful option- in this way, the wind (freely available and renewable) can be used not only to create power for the grid, but also to electrolise water and gain hydrogen; the hydrogen is thus made without damaging the atmosphere with fossil fuel pollutants and CO2, and the hydrgoen thus gained can be used as an alternative power source when wind or sunlight is not strong. The energy sources thus bolster each other. The use of excessive energy to store the hydrogen (a very delicate substance), however, would still need to be reversed.
The main argument against using hydrogen as an alternative fuel, then, is that it isn’t freely available (like wind) and needs energy to ‘create’ it- and this use of energy in hydrogen’s production can also have the side effect of producing harmful greenhouse gases and pollutants.
Amongst other issues is the fact that hydrogen is a gas at most temperatures, which requires energy to store and maintain.
Motorised vehicles, for which hydrogen has been historically linked in an optimistic manner, are generally being converted to electricity instead; Ford have dropped all plans to make hydrogen powered cars, and are instead planning only to electrify their vehicles.
Despite these issues and concerns, hydrogen production is nevertheless a large expanding indistry. According to the Chemical Economics Handbook, SRI, July 2001, it is estimated that 50 million tons of hydrogen were produced globally in 2004, next to 170 million tonnes of oil. According to the University of Leeds, the growth rate of hydrogen, worldwide, is around 10 per cent per year
At present, the figures show that barely any of the hydrogen being produced is coming from renewable sources- figures seem to agree on about 5%. The rest is from dirty fuels. The Chemical Economics Handbook puts the percentages of energy methods for procuding hydrogen at 48% natural gas, 30% oil, and 18% coal, water electrolysis 4%- a miserable figure from a green perspective.
Let us hope, then, that if this form of energy will continued to be used in such large quantities, a severe reversal happens in how it is produced; and if not, then other sources of energy are quickly found to replace it.
Posted under Climate, Electricity Generation, Gas & Electricity, Renewable Energy
This post was written by Barnaby Tidman on December 3, 2009
-->
















