Tuesday, January 22, 2008

An Energy Plan

To start, we should look at some energy numbers. These apply to the US only. Here are the quantities of energy the US used in 2006, in quadrillion British thermal units, usually called quads:

quads %
Renewable 0.329091699 0.216726496
Hydro 0.987196598 0.650127793
Nuclear 2.686778447 1.769403728
Fossil-fired Elec 9.844436722 6.483148269
Other Fossil 137.9990426 90.88059371
TOTAL 151.8465461 100


Note, if you will, that fossil-fired electricity accounts for only 6.5% of the energy even though it accounts for 40% of the CO2 emissions.

This analysis comes in two parts. First we'll cover electricity. We know the rate of electricity generation will go up because a lot of the schemes for reducing greenhouse-gas emissions require shifting fossil-fuel applications to electricity: battery-powered cars, light-rail transit systems, replacing furnaces with heat pumps, etc.

Renewable energy sources such as wind and solar can't replace fossil fuels owing to their part-time natures. But they can greatly reduce the amount of fossil fuels being burned during the transition period while renewable and nuclear sources are being installed. So our plan includes both renewable and nuclear.

But wait, there's more! Electricity is a big part of the problem but not the only part. We also have to replace petroleum-based motor fuels. At this point, there are only two possibilities in view, besides electrified vehicles, bicycles, foot travel, horseback, rickshaw and some other specialized transportation modes. The two possibilities are hydrogen and hydrogen-enriched biofuels, as we discussed in the article, "The Dimensions of the Challenge." Our plan needs to include the capability of producing large amounts of hydrogen. This plan does that, because nuclear plants allow for thermochemical production of hydrogen, by far the most efficient technique available.

Once all the fossil-fired power plants are replaced, nuclear and renewables can complement each other. The nuclear plants can provide whatever electricity is needed during times of dim sunlight and low winds, or no sunlight and no wind. When the sun is shining and the wind is blowing, and when demand for electricity is low, nuclear plants can divert some of their capacity to generating hydrogen.

This plan allows solar and wind to play their maximum part in providing electricity. Further, it allows them to contribute efficiently to the production of hydrogen.

I don't want to claim that this is the only energy plan that could work. But it is the only plan I've seen that could work. If you know a better plan we'll do it your way instead. However, if your plan doesn't allow for providing electricity when the sun isn't shining and the wind isn't blowing then you don't have a plan.

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