| Hydrogen is often cited as the solution | | | | It takes energy to make energy. We use |
| to global energy problems and the | | | | energy to find and pump oil but, luckily |
| perfect energy carrier for a sustainable | | | | for industrial society, oil has huge net |
| society due to its’ non polluting | | | | energy and we can usually obtain more |
| nature and suitability to store and | | | | than 200 times the amount of energy from |
| transport energy generated from | | | | oil than is required for its’ |
| renewable sources. This essay examines | | | | extraction. Oil has the highest net |
| the practicalities of a hydrogen-based | | | | energy return of any fuel; gas, coal, |
| energy system and its’ ability to | | | | wind and solar all have dramatically |
| provide a sustainable future. | | | | less. Hydrogen has negative net energy |
| Many people including Romano Prodi, | | | | meaning it takes more energy to produce |
| president of the European Commission, | | | | it than it contains, this highlights the |
| President Bush and numerous "deep | | | | first problem of a hydrogen society. |
| greens" including Amory Lovins, author | | | | Counting Calories |
| of Natural Capitalism advocate the | | | | Although it is the most abundant element |
| "hydrogen economy" as the future of | | | | in the universe hydrogen is not very |
| world energy supply. The justification | | | | easy to obtain. Ironically, petrol is |
| seems well founded; a renewable energy | | | | the most concentrated form of hydrogen |
| plant generates electricity | | | | available for human consumption |
| sporadically, hydrogen can be produced | | | | containing more hydrogen by volume than |
| by the electrolysis of water, storing | | | | pure hydrogen itself, since the |
| energy in the form of hydrogen negates | | | | structure of the atoms in hydrocarbons |
| the need for large and inefficient | | | | use less space. Hydrogen also has a very |
| batteries (and associated pollution) and | | | | low calorific value (a gallon of petrol |
| fuel cells (fig. 2) can turn hydrogen | | | | has 115,000 btus, a gallon of liquid |
| back into useful electrical energy | | | | hydrogen has only 30,000 btus) so it |
| (using oxygen from the atmosphere) as | | | | takes about 4 times the volume of |
| and when required, the only by-product | | | | hydrogen (compared with petrol) to |
| being steam or water. | | | | travel the same distance, requiring |
| The associated benefits include the | | | | larger and heavier fuel tanks |
| elimination of exhaust pollution | | | | (compressing or liquifying hydrogen uses |
| (sulphur dioxide, carbon monoxide, | | | | more energy) which require additional |
| carbon dioxide and other particulates | | | | energy to transport. This low calorific |
| associated with the combustion of fossil | | | | value dictates increased volumes (or |
| fuels) particularly in cities, the | | | | high pressures) throughout the entire |
| associated reduction in global warming | | | | hydrogen system. |
| and the ability to generate power | | | | Hydrogen manufacture |
| locally promoting the development of a | | | | There are several ways to obtain |
| decentralised energy system. It is even | | | | hydrogen; by electrolysis of water, by |
| suggested that ultimately a hydrogen | | | | splitting water using light, by |
| economy would help avoid global economic | | | | collecting and reforming gas from |
| downturn due to unmanageable increase in | | | | biomass, by reforming natural gas or any |
| peak demand and the limited supply and | | | | other fossil fuel. Each of these |
| increasing costs of fossil fuels. | | | | processes is extremely energy intensive |
| Don’t believe the hype | | | | and always results in hydrogen with a |
| It’s easy to be convinced by stories | | | | negative net energy, electrolysis (the |
| we want to believe. Ergo magazines | | | | cleanest and most appropriate process |
| claims hydrogen ‘is the one’. Jeremy | | | | for obtaining hydrogen from wind and |
| Rifkin, head of the Foundation on | | | | solar power) is the most energy |
| Economic Trends claims the hydrogen | | | | intensive of them all – roughly 75% |
| economy will be ‘the next great | | | | efficient and costs roughly four times |
| economic revolution’ James Burges | | | | as much as reformation. The simplest, |
| thinks it ‘may be our only option for | | | | cheapest and most efficient process is |
| survival’; hydrogen is the answer. | | | | the reformation of natural gas, an |
| However, critical analysis of the | | | | established industry, yet this is still |
| properties of hydrogen and the necessary | | | | only 85% efficient. It is therefore less |
| steps in a hydrogen society reveal a far | | | | polluting and resource intensive to |
| less optimistic picture. | | | | simply burn natural gas. |
| Net Energy | | | | |