Powering the world by alternative energy

By Michael Evans - 16 Feb 2011 14:44:0 GMT
Powering the world by alternative energy

Two US researchers have produced a plan claiming that existing technology could be used to halt global warming, reduce air and water pollution, develop secure and reliable energy sources and save between 2.5 and 3 million lives each year, at costs comparable with what the world currently spends on energy.

Professor Mark Jacobson from Stamford University and Dr Mark Delucchi of the University of California-Davis maintain that this could be accomplished if the world converted to clean, renewable energy sources and abandoned fossil fuels.

Writing in the magazine Energy Policy, they assess the costs, technology and material requirements of converting the planet. They envision a world run largely by electricity with 90% of this provided by wind and solar power. Geothermal and hydroelectric sources would each contribute a further 4%, with the remaining 2% coming from wave and tidal power. The point out that 70% of the hydroelectric capacity is already in place.

In this world of the future all vehicles, ship and trains would be powered by electricity and hydrogen fuel cells. Aircraft would run on liquid hydrogen and houses would be warmed or cooled by electricity, with no more natural gas or coal. The sun would preheat all water.

Electricty and hydrogen would power all commercial premises and in all cases hydrogen would be produced from electricity. The stage would thus be reached when wind, water and the sun would power the world.

This all might seem a bit fanciful, but the researchers firmly believe that this is achievable. Their goal is that all new energy would come from wind, water or the sun by 2030 and that all pre-existing energy production would be converted by 2050.

One of the benefits of the plan, say the researchers, is that it will result in a 30% reduction in world energy demand since it involves converting combustion processes to electrical or hydrogen fuel cell processes and these are much more efficient than combustion. That reduction, together with the millions of lives saved by the decrease in air pollution resulting from the elimination of fossil fuels, will help to keep down the costs of conversion.

''When all present costs, including medical costs have been taken into account,'' says Professor Jacobson, ''the costs of our plan are relatively similar to what we have today.''

Of course, one of the biggest hurdles to overcome is the fact that wind and solar energy can be highly variable. This obviously raises doubts as to whether either source is reliable enough to provide the minimum amount of energy that must be available to customers at any given hour of the day.

Professor Jacobson thinks that this can be overcome. Wind often peaks at night, sunlight peaks during the day and hydropower can be used to fill in the gaps. This will allow demand to be precisely met in most cases. Using long distance transmission will also help to match supply with demand.

Based on their findings, the two researchers see no technological or economic barriers to the plan that they have developed, it is simply a question of gaining acceptance by politicians and society in general.