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Fusion Reactor Concept Could Be Cheaper Than Coal
vinces99 writes Fusion energy almost sounds too good to be true – zero greenhouse gas emissions, no long-lived radioactive waste, a nearly unlimited fuel supply. Perhaps the biggest roadblock to adopting fusion energy is that the economics haven't penciled out. Fusion power designs aren't cheap enough to outperform systems that use fossil fuels such as coal and natural gas. University of Washington engineers hope to change that. They have designed a concept for a fusion reactor that, when scaled up to the size of a large electrical power plant, would rival costs for a new coal-fired plant with similar electrical output. The team published its reactor design and cost-analysis findings last spring and will present results Oct. 17 at the International Atomic Energy Agency's Fusion Energy Conference in St. Petersburg, Russia.
Costs are a big issue, but the problem with fusion is getting more energy than is put in... and keeping that reaction sustained indefinitely. Yes, one can get energy out, and sometimes more energy out for a brief bit with a tiny gold-plated capsule... but there is a huge jump from pulverizing a mini-nugget with a big boom to having a reactor that you can turn on, and let it power stuff on an indefinite basis. Same difference between an explosion from TNT and the small, controlled explosions pushing pistons down in an IC engine.
In the TFA, supposedly their dynomak [1] actually does a sustained reaction, but the key is how sustained. Even at a couple kilowatts, if it can just sit there and act as a steam turbine, it will power a UPS for a long time. Scaling up to megawatts is where it solves the big problems, because it can power desalination plants to keep California habitable and other things which are energy/cost prohibitive as of now.
As always, I hope this succeeds. Energy is money, and the more energy available, the more a country and a people can do.
[1]: Is it that different from a tokamak which have been in use for decades?
I thought the biggest roadblock to adopting fusion energy was that it doesn't work?
(I'd like to be positive and add "yet" to that sentence, but still.)
Here's the project conference poster. "Total equipment cost for the development path is less than $1 billion". Nothing on the poster, though, indicates why this should work. It's yet another torus-based design, of which there have been many. The best performance to date is from the Joint European Torus: "In 1997, JET produced a peak of 16.1MW of fusion power (65% of input power), with fusion power of over 10MW sustained for over 0.5 sec."
All torus designs run into plasma instability problems. So far, nobody has a working solution. Nobody even has a good theoretical solution. No combination of fixed magnets has yet worked. There's some modest interest in active feedback for stabilization, and some modest success has been reported. The instabilities are on the order of milliseconds, so active feedback is quite feasible.
Even ITER probably won't work. The thinking behind ITER was originally "maybe it will become more stable if we make it bigger." Now, a little "maybe the feedback control people can make it work" has been added. It's not looking good, which is why there really isn't that much enthusiasm for ITER.