Posted by: bmeverett | January 15, 2014

Fusion confusion


George F. Will is one of the very best political commentators on the scene today. His writings have been a treasure trove of thoughtful and articulate conservative thought for decades. Unfortunately, his December 21, 2013 column entitled “The Fusion in our Future” is way off the mark. The column is a call for government spending on fusion technology. OK, but I was saddened by his decision to ignore economics – a rookie mistake for a veteran thinker.

Nuclear fusion is a well-understood process in physics. When certain light atoms are fused into a heavier element, the force required to hold the heavier nucleus together is less than the force required to hold the light nuclei together. The difference is released as energy. The ideal fusion reaction involves deuterium, an isotope of hydrogen with a nucleus of one proton and one neutron, and tritium, another hydrogen isotope with one proton and two neutrons. If these two atoms can be brought close enough together, they will fuse to form helium with two protons and two neutrons, releasing one neutron plus 17.6 million electron volts of energy. This huge energy release is the source that powers the Sun and the basis for thermonuclear bombs.

The fission reaction, in which the nuclei of heavier atoms are split into lighter elements, is the basis for the much smaller atomic bombs, such as those dropped on Hiroshima and Nagasaki. The fission process turned out to be relatively easy to control for civilian applications, like nuclear power plants. A fission reactor contains rods of fissionable material, like uranium and plutonium, interspersed with rods of material that absorbs some of the reaction energy, allowing the total energy release to be controlled.

Scientists have been working on controlled fusion energy since the early 1950s, but the process has been frustrating. Forcing the nuclei of light elements together essentially means heating them to very high temperatures – on the order of 100 million degrees Celsius. Thermonuclear bombs generate this heat by exploding a fission bomb. Generating 100 million degrees C in a contained environment without melting the entire installation turns out to be a challenge. Furthermore, although hydrogen is the most common element in nature, only about 1 out of every 6,500 hydrogen atoms are the deuterium isotope and only one out of 1,000,000,000,000,000,000 hydrogen atoms are tritium. Obtaining these materials is difficult, expensive and energy-intensive.

During the late 1970s, there was a school of thought in Washington that the problems of fusion energy were about to be solved and that we should anticipate having commercially viable fusion power plants around the year 2000. As a result, we faced only a couple of decades of transition before we could eliminate fossil fuels and enter an energy nirvana. Needless to say, that view proved overly optimistic.

The US and several other countries continue to fund fusion research, although at lower levels than in the past. The US program is about $250 million per year. Mr. Will sees this funding level as inadequate, since he has apparently determined that more money will produce the success that has eluded us for all these years. His view is that research outputs are proportional to financial inputs. Wrong.

Technologies undergo three basic stages of development. The first stage is conceptual – a good idea. We know that fusion works, since can make fusion bombs. The second stage is technical – making machines that actually work. Solar and wind energy, for example, reached this stage many years ago. We can produce solar panels and wind turbines that generate electricity. Fusion has not reached this stage, since we have never been able to produce a machine, even at the research level, that can generate more energy than is required to run the machine. The final stage is commercial – the ability of the technology to replace existing technologies with better and/or cheaper results. Wind and solar still have not reached this stage, since both technologies underperform their competition and cost much more.

Mr. Will’s mistake is his focus on the technical stage as the indicator of success. It is possible (although by no means assured) that a substantial increase in funding could allow researchers to build a fusion reactor that actually works. It’s quite another issue to design a fusion reactor that can produce electricity at a competitive cost. Just for calibration, modern combined cycle power plants burning natural gas can generate electricity in the US at about 6¢ per kilowatt-hour (kWh). By contrast, onshore wind and nuclear power cost about 10¢. Offshore wind costs much more – about 20¢ and solar in the range of 30¢.

Even if we can solve the technical problems around fusion, how much will it cost? Well, as Mr. Will points out, tritium can be produced in the reactor itself, while the oceans contain 10 million million tons of deuterium. Sure, but how much would it cost to extract the deuterium from the ocean? Every cubic kilometer of seawater contains about 13,000 grams of gold worth about $500,000. Why aren’t people extracting gold from seawater? Because it costs more to get the gold out than it’s worth.

Even if the fuel turns out to be free, how much would the reactor cost? Suppose we could build a functioning fusion reactor for $20,000 per kilowatt, and it could operate 95% of the time. The reactor could generate 8,322 kWh per year (24 hours X 365 days X 95%). Even if the reactor were financed with 5% 30 year Treasury bills, the capital cost alone would require revenue of 12¢ per kWh. At commercial return rates of 12-15%, the capital cost of such a facility would be in the range of 30-35¢ per kWh. That doesn’t include the cost of operating and maintaining the power plant.

Surprisingly, Mr. Will has made the mistake for which he usually criticizes the political left. He believes the government can make better commercial decisions than the market. I’ll grant Mr. Will at least this much. There is an argument for the government to do basic science research that the private sector is unwilling to do. When it comes to the government’s ability to pick commercial technologies, however, just remember Solyndra and back away slowly.

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