Fusion power, that is, commercially viable, grid-scale fusion power, is still as wags have been describing it; 20 to 30 years away, just as it has been for 50 years. There are still technological challenges to overcome, although several teams are working on them and making progress. But there's also the problem of economic viability.
That is the question: Economics. It's always economics, after all. Fusion reactors are massively complex and massively expensive - now. Will that be changing? Technology tends to get cheaper over time. Some of us are old enough to remember the first pocket calculators, which in the 1970s cost around a hundred bucks. Within a few years, businesses were giving away small, solar-powered pocket calculators as promotional items.
Are we nearing viability on both counts? First, the economic problems:
Tobias Schmidt, founding director of the Albert Einstein School of Public Policy at ETH Zurich, lead author Lingzi Tang, and two others published their findings in Nature Energy on March 23. They concluded that the large unit size, extraordinary complexity, and intermediate need for customization of FPPs are empirically linked to experience rates (cost reductions for additional units) of 2% to 8% rather than the industry’s estimates of 8% to 20% – and that, paired with expected high initial capital costs, spells financial doom for the fledgling industry.
Schmidt told Techxplore.com that, after hearing promises from “some actors in the fusion space” of extremely low levelized costs for FPPs, his team applied to fusion an ETH framework that analyzes why some technologies learn with higher experience rates than others. The team compared magnetic fusion (which prompts fusion by confining hot plasma using powerful magnetic fields) and inertial fusion (which works by compressing fuel using lasers).
Casey Crownheart, writing for MIT Technology Review, said the ETH team asked fusion experts to evaluate FPPs on size, complexity, and customization to predict an experience rate. Tang told Crownheart that “there was almost unanimous agreement that fusion is incredibly complex,” and that reaching the experience rate of 23% for solar modules, 20% for lithium-ion batteries, or even 12% for onshore wind power was highly unlikely.
That's a significant problem. The experience rate, in this context, describes how the unit cost of a product, in general, declines by a certain percentage as the production volume increases. An experience rate of 80 percent means that the cost of a new technology decreases by 20 percent each time production doubles. That's the phenomenon I mentioned above, with pocket calculators.
But with fusion reactors, the initial cost, the initial investment required, is enormous. And any such system has to be not only technologically, but commercially viable, or else we are stuck in the same expensive groove as the industries pushing expensive, low-density energy solutions like wind and solar power. Will fusion power's initial costs make that difficult?
The various teams and organizations are still working on the technology, as well:
Not coincidentally, CFS (Commonwealth Fusion Systems) is building its prototype FPP – the SPARC (smallest possible affordable, robust, compact) tokamak – in collaboration with MIT at its Devers, Massachusetts, facility, with completion now scheduled for 2027. CFS CEO Bob Mumgaard says it will be the world’s first commercially relevant fusion energy machine to produce more energy from fusion than it needs to power the process – or net energy generation (Q>1).
Mumgaard went on the record with Reuters’ Tim Gardner, just days after the ETH Zurich report was published, and spoke extensively about the progress his company is making toward its goal of building a larger FPP in Virginia starting in this decade. Mumgaard noted that the ETH Zurich authors are unaffiliated with fusion (Schmidt even said they would not be doing further studies on fusion costs). These academics did not contact him or anyone who is building “anything.”
“When you actually look at … the speed at which we’re able to build our things, the ability that we’ve actually shown to decrease the cost of every component that goes into it, those are following well-known industrial trends that are not from the 1950s or 1960s but are from today. And so we remain very bullish that power bills in Virginia in the 2030s will include fusion.”
That's an optimistic assessment. It's also the assessment of a company that has already sunk considerable capital into this system. Now, once a design is working, after that it becomes a matter of mass-producing it; will that be enough? Fusion power is still tomorrow's technology, but the benefits of a workable, commercially viable fusion reactor are enormous: Clean, reliable, high-density energy, with greater energy density than even fission reactors.
Remember, every single major advance in human society has been accompanied by a major advance in the energy density of that society's primary fuel source. This could be another such event.
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CFS is still claiming they will have a working tokamak fusion reactor working sometime in 2027. Will they meet that goal? And will the thing be not only practically but also commercially viable?
Ay, that's the rub. Both the economic and technological aspects have to be practical. It's not enough just to make a working fusion reactor that returns a positive output, that produces more usable energy than it takes to start the thing up. It also has to be able to produce a return on investment; it has to be able to run at a profit for the companies and utilities that are building them. That's going to be the key; that's going to be what makes fusion energy either a society-changing new technology or just another expensive, subsidized energy boondoggle.
