Energy

University of Washington fusion reactor promises "cheaper than coal" energy

The University of Washington's HIT-SI3 experimental reactor (Photo: University of Washington)
The University of Washington's HIT-SI3 experimental reactor (Photo: University of Washington)
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The University of Washington's HIT-SI3 experimental reactor (Photo: University of Washington)
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The University of Washington's HIT-SI3 experimental reactor (Photo: University of Washington)

In the 21st century, the world lives with two futures ahead of it – one of looming energy shortages, and another of godlike energy abundance. The key to this whether it’s possible to turn fusion reactor technology from a laboratory exercise into a real-world application. Engineers that the University of Washington (UW) are working on a fusion reactor that, when scaled up, could produce energy on a practical scale, yet at a cost rivaling that of a conventional coal-powered plant.

Nuclear fusion, as the name implies, is based on fusing hydrogen atoms to form helium; a process that releases tremendous amounts of energy. According to science writer Ben Bova, a single glass of water could produce as much energy as half a million barrels of petroleum. It would also be safer than current nuclear plants that rely on splitting heavy atoms, there would be no chance of a meltdown or spewing radioactive fuel into the air, and very little radioactive waste. And since it uses hydrogen as fuel, there would be enough to last until the end of time.

Long term, its looks brilliant, but at the moment it’s a hopeless non-starter that’s too impractical and too expensive to leave the laboratory. With the exploding of the first hydrogen bomb in the 1950s, fusion reactors seemed around the corner, and they were predicted to be in common use in 25 years time. Unfortunately, that kept being the case and remains so today; fusion power is always 25 years away.

To recreate fusion on Earth without using atomic weaponry, a machine needs to be built that can recreate the conditions inside the Sun, which is basically a giant fusion reactor. That means a container that hot enough and under enough pressure for the fusion process to start. Though fusion reactors were built over fifty years ago and a bench-top version was featured at the 1964 New York World’s Fair, producing a reactor that went beyond the experimental and into the practical remains elusive.

Part of the problem is to balance the energy equation. Getting hydrogen to fuse is one thing. Getting it to do so while producing more energy than you pump into the reactor to run it is another. Even if you manage that, you still need to generate that energy at a low enough cost to compete with conventional sources.

The main contender for winning that prize at the moment is ITER; an international project to produce a practical fusion reactor. Located in Cadarache, France, the ITER reactor is a joint venture between the United States, the EU, India, Japan, South Korea, China, and Russia.

It uses a tokamak design. that is, a giant torus surrounded on the sides and in the core by superconducting magnets generating tremendous energy. These create a magnetic field inside the torus that squeezes together, contains, and heats hydrogen into a plasma, which at the right temperature and pressure start to fuse. It’s a very advanced technology and brings us closer to the fusion age than ever, but it still a long way from the finish line. Though still under construction, the economics if ITER don’t look good with cost per kilowatt well outside of what conventional sources can produce.

The UW approach has more modest roots as a project in a 2012 class taught by Thomas Jarboe, a UW professor of aeronautics and astronautics and an adjunct professor in physics, and later taken up by Jarboe and doctoral student Derek Sutherland. Called Dynomak, the new concept reactor is simpler than ITER by a factor of ten, yet has the potential of making more energy at less cost.

According to the UW team, Dynomak builds on existing technology, such as an ITER-developed cryogenic pumping system. Technically, its a spheromak, which means that instead of a torus, it’s a simple oblate spheroid. There’s no central core and it doesn’t need the large, complex superconducting magnets that ITER uses. Instead the magnetic fields are produced by putting electrical fields into the center of the plasma using high temperature superconducting tapes wrapped around the vessel, so, in a sense, the plasma contains itself.

According to the UW team, this means the Dynomak is smaller simpler, and cheaper to build, yet produces more power than the ITER reactor. Also, since the plasma heats itself, the fusion reaction is self-sustaining as excess heat is drawn off by a molten salt blanket to boil water to run a steam turbine to generate electricity.

If the UW’s calculations are correct, a Dynomak reactor would cost a tenth of ITER and produce five times as much energy at an efficiency of 40 percent. that means that a one gigawatt Dynomak power plant would have a total cost of US$2.7 billion against the US$2.8 billion needed to build a coal plant

The UW team says that the current Dynomak is only ten percent of the size and power of a practical reactor, which years away in terms of development. However, they say that the test reactor has so far demonstrated its ability to sustain a plasma and they plan to increase the temperature and power output of the unit.

"Right now, this design has the greatest potential of producing economical fusion power of any current concept," says Jarboe.

The UW team’s findings were published in Fusion Engineering and Design.

Source: University of Washington

41 comments
Derek Howe
awesome, but I always wonder if something like this would ever get built, since it would cause a huge change to the status quo.
BobMunck
"According to science writer Ben Bova, a single glass of water could produce as much energy as half a million barrels of petroleum." Heavy, man. Heavy. Practical fusion energy is always 50 years in the future, no matter how many years pass. Gotta' love the name, though "Dyn-O-Mak!" I'm sure we all hear it in JJ Walker's voice.
Dennis Learned
I shake my head when I think of how electricity is usually produced. Take hydro power. Build a big dam and let a large body of water form. Allow the water to run through a turbine and a generator to produce electricity. Or, get a heat source (gas, oil, coal, nuclear, concentrated sunlight), boil water, make steam, use steam to spin a turbine, use turbine to spin a generator to produce electricity. Seems to me there are always two or several conversions in the process which produce losses. We need a way to generate electricity directly. Oh, we have a couple of ways: solar cells, wind. Not totally reliable. Geothermal and thermocouples? Hydrogen fuel cells? I suppose there are always some losses an any system.
andyfreeze
In the year 9595, if man is still alive, they may find......... as much as i like to read about advances in fusion, i think its in the pure research that it will stay. nuclear and all its derivatives have had a window of opportunity that lasted more than 60yrs. with the development of solar cells and other forms of energy, that window is closing rapidly. what a stupid prediction that it would only cost $2.7b . this figure is pure fairytale. what about all the "other costs" that get picked up along the way? waste products, if any scientific and engineering training location engineering and siting as no one will be happy about this in the back yard what other insurmountable obstacles will prop up? who will fund this amount of money if not a government? what are the dangers? i can see it going $40b and up. it just cannot be justified on any scale. guys, if you like pure research, go for it. if like me , you have to pay for it, its just not on. 5kw solar pe system can cost as little as $5000 au, that will do me, thankyou!
Nairda
The only joke I see here is the price of research for fusion. Make the cost big enough to spook all the hippies back to solar panel and wind turbine mentality. And we all know those trophy pieces can't generate enough power to feed our needs, so we default to hydrocarbons as the only solution in our 'struggling economy'. Sell it how you like, but absolute truth cannot be destroyed.
Brian M
Fusion is not a maybe technology, the scientific basis is fine and it works. The real problem is the engineering required to scale the science into a practical machine. Given the befits it will be only a matter of time, its just how much time!
Mel Tisdale
If only we could take all the funding for these fusion research programmes and pump it into LFTR (thorium) fission reactors, we might arrive at the situation where we have nuclear electricity generation that is not only cheap and walk away safe, it cannot be used to make a bomb (not one that doesn't scream "Here I am!" to any nearby detector and not without fatally irradiating the bomb maker and his or her mates). Had Fukushima employed thorium reactors, it would not have been half the incident that it turned out to be. As for the redundant fusion researchers, well, they could be set the task of finding the cheapest/most efficient way of electrifying transportation and agricultural vehicles so that we can use the electricity that is produced. We are going to have to do that anyway as the easy oil peters out, so the sooner they start, the better. I will add one caveat. NASA are experimenting with cold fusion, so there must be something in it. I would like to see some long-term plan that shows what power generation it is likely to be capable of and by when, before I write off everything with 'fusion' in the title.
watersworm
Bref... rendez-vous dans 25 ans (or more ?)
piperTom
Article says the "machine needs to ... recreate the conditions inside the Sun". Ummm, No. Very much: NO! The sun creates roughly 3 times ten to the 26 watts. It does this in its core, about 3 * 10**11 cms in radius. That is 2.7 (or, rounding up) 3*10**34 cubic centimeters in volume. So the sun gets by making 10 nano-watts per cubic centimeter. Your Machine needs make energy at least a hundred trillion times more intensely than the Sun.
AllenH
Fusion research should continue, but funding for various energy production ideas needs to be allocated based on viability. And don't forget continued work to improve existing energy sources. Nuclear power is an important piece of that (if we can get past the political scaremongering). The record in the US and western countries is excellent. Research should also focus on smaller generation options. For example, the Navy has a long track record with small and medium reactors used to power aircraft carriers and submarines. What are the benefits to deploying this size of reactor commercially? Hydraulic fracturing (aka fracking) is yielding tremendous amounts of natural gas and oil from shale rock. Scrubbing technology has reduced emissions from coal powered plants to a tiny fraction of what they were a generation ago. Making these advances more cost-effective benefits a very significant sector of the economy. Wind and solar are helpful, but limited because of their intermittent nature. So using them to pump water into reservoirs as a means of energy storage would make them more practical. Thorium energy was already noted by another person here as a very promising alternative to uranium based nuclear power. A little more research could easily bring this technology to market. Again, continue researching fusion, but don't overlook other technologies in the process or their viability as a criteria for awarding research funds.
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