Is Fusion Even Worthwhile?
This week's Economist carries an acerbic analysis of the rivalry over where the International Thermonuclear Experimental Reactor should be sited. While their insight into the tussle--as a proxy for the rift over the Iraq War--rings true, their conclusion that fusion research has no value is shortsighted and poorly reasoned. Fusion could be a valuable, even an essential, component of the future post-hydrocarbon energy mix.
The article observes that practical nuclear fusion--which releases energy by combining lightweight atoms, in contrast to the splitting of heavy atoms achieved in nuclear fission--has always appeared 30 years off. Fair enough; I would have said 40. But in dismissing it as permanently uneconomical and marginal, they ignore the benefits that have convinced a number of governments to fund research in this area for decades, despite the absence of a home run.
Fusion offers the potential of limitless, clean power. Even when one reins in this nirvana-like vision, fusion gives us a realistic possibility of high density, cost-competitive power generation with very little in the way of the emissions or radioactivity that make all of today's central power plants unattractive. This sounds like something well worth pursuing, at least at the relatively modest sums that are being contemplated. But what is missing here and what the Economist has ignored entirely is a vision of where fusion might fit in a future global energy system.
The most frequently mentioned alternative to our hydrocarbon-based energy system is a hydrogen economy. But a hydrogen economy still needs an energy source to produce the hydrogen. In the long run, that means doing so without creating more of the kinds of emissions that impel us to want to switch to hydrogen in the first place.
The only options meeting this criterion today would use electricity from wind or solar power to break water into hydrogen and oxygen. This approach suffers from two serious shortcomings:
- Generating the necessary quantity of electric power from these sources would require covering vast swaths of territory with windmills or solar collectors. There is ample evidence of environmental pushback to this.
- It may not be possible to build wind and solar installations fast enough to keep up with growing demand for electricity, let alone being able to replace the energy content of petroleum fuels.
Moving the solar collectors into orbit could solve both of these problems, but it would require a much larger and cheaper (in terms of cost per pound in orbit) space program than anything our politicians seem willing to support.
So what is needed to make a hydrogen economy not only possible but desirable in the long run is a concentrated, essentially zero-emission source of electricity that doesn't blight the landscape. Conventional nuclear power plants or their advanced technology offspring might fit the bill, but they would still leave us mired in endless debates about nuclear waste, as well as vulnerable to further nuclear weapons proliferation.
Ultimately, if the suggested timescales are finally right, and fusion research delivers an economical product by around 2040, it would provide an ideal means for converting a hydrogen economy begun with hydrogen from natural gas and other fossil fuels to a permanent, non-fossil energy source. If the nations of the world aren't willing to come up with $10 billion to fund a bet like that, maybe we could raise the money on the Internet.
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