There’s a lot of excitement about a new approach to fusion power:
• Henry Fountain, Compact nuclear fusion reactor is ‘very likely to work,’ studies suggest, The New York Times, 29 September 2020.
Scientists developing a compact version of a nuclear fusion reactor have shown in a series of research papers that it should work, renewing hopes that the long-elusive goal of mimicking the way the sun produces energy might be achieved and eventually contribute to the fight against climate change.
Construction of a reactor, called SPARC, which is being developed by researchers at the Massachusetts Institute of Technology and a spinoff company, Commonwealth Fusion Systems, is expected to begin next spring and take three or four years, the researchers and company officials said.
Although many significant challenges remain, the company said construction would be followed by testing and, if successful, building of a power plant that could use fusion energy to generate electricity, beginning in the next decade.
This ambitious timetable is far faster than that of the world’s largest fusion-power project, a multinational effort in Southern France called ITER, for International Thermonuclear Experimental Reactor. That reactor has been under construction since 2013 and, although it is not designed to generate electricity, is expected to produce a fusion reaction by 2035.
But fusion has been twenty years off since the 1950s. What’s the evidence that Sparc will work? I guess most of the evidence is here—a series of seven papers, which luckily are available open-access:
• Status of the SPARC physics basics, Journal of Plasma Physics 86 (2020).
I have not read these! And even if I did, since I’m not an expert on fusion reactors—obviously a tricky subject—I’m not sure how much my impression would help.
Do you know any commentary on SPARC from other experts on fusion reactors? The more detailed, the better. All I’ve seen so far are very sketchy remarks from people who don’t seem to know what they’re talking about.
Azimuth 
Is the ITER project taking so incredibly long because of funding constraints, or some other reason? Is there a good source for the answer? Thanks.
Here’s a story written in 2017:
• Henry Fountain, A dream of clean energy at a very high price, The New York Times, 27 March 2017.
A quote:
I don’t know what’s happened since 2017.
Another promising idea: https://youtu.be/7qJpVClxzVM.
As a vaguely related aside, I was watching a series of interview clips the other day, and I believe it was the great Roger Penrose who commented that, while mathematicians usually move towards elegance, simplicity, and symmetry, fusion physicists shun it because an elegant, simple, symmetrical solution is guaranteed to be wrong. Fusion physics, apparently, is messy, complex, and intricate.
Which, perhaps, is why it’s been “about 20 years away” for over 50 years. :)
I’ve heard that the problem of confining plasma is a bit like trying to balance a cooked strand of spaghetti so it stands upright on your finger.
It’s amazing that until recently a lot of models of star formation and stellar collapse assumed spherical symmetry, which is completely wrong: we’ve got a spinning ball of plasma, it tends to form jets at the poles, etc.
biconic cusp confinement (astroid of revolution?)
I’m surprised they didn’t try to make the confinement self-generating. “Higher temp superconductors” sounds like a “money pit” fix.
Someone on the original GE team supposedly remarked, something like, “it’s easier to make a diamond out of peanut butter than to make peanut butter out of a diamond”.
oh, and plasma windows (think shuttle bay force field).
I always got a kick out of the Enterprise using “EPS” conduits, which are plasma pipes, for electrical wiring. But I guess if you’re going to convert small groups of entire humans from matter into energy (and back again somewhere else), you probably would need the current carrying capacity of something like a plasma conduit, ’cause that’s a lot of energy.
Many times the strong magnets from old 20MB hard disk drives have slipped through my fingers. They do something like a Fosbury Flop and then slam back into each other with a bit of skin caught between them. I was taught Earnshaw’s theorem was the reason that it would be impossible to arrange magnets so that one of them was statically levitated. But a smaller neodymium magnet can be statically levitated by placing some bismuth plates (made from eco-friendly shot gun shells) around it. Many people have since done this to satisfy their disbelief. Some have experimented with different shapes of bismuth ‘shields’. But I still don’t have a good idea how shaded-pole or ball-bearing motors work.
Small, modular & economically attractive fusion enabled by high-field superconductors, Youtube DR. DENNIS WHYTE, UC Berkely (1 hr 11min)
Tailoring Magnetic Fields in Inaccessible Regions
“Our strategy leads to an unprecedented focusing of magnetic fields in empty space and enables the remote cancellation of magnetic sources, opening an avenue for manipulating magnetic fields in inaccessible regions.”
I am not familiar with the SPARC approach or the MCF side of the fusion research; however, direction of the energy sector is increasingly clear with the current rise of renewables (LCoE of PV and wind @ ~$20/MWh, with PV learning curve aiming for ~$10/MWh in 2030s). In fact, it is likely that any thermal cycle power plant will find it extremely hard (if not impossible) to compete with renewables based on the capital expenditures on the turbine side itself with zero capital spent on the steam production side.
In terms of ancillary services such as grid balancing or voltage/frequency control these can be solved much more cheaply via grid integration and demand-side measures (ERCOT in Texas already has some interesting demand-side measures) – this is documented by the research into smarter regulation and introduction of smart meters.
People who claim wind and solar aren’t enough often say the intermittent nature of these power sources requires us to keep nuclear power or other “on-demand” sources of power. Are you saying that can be minimized—or eliminated entirely?
‘Intermittent’ is not the right word (albeit commonly used by parties with vested interests in fossil conventional generation) – it is preferable to call these variable resources. Nowadays it is commonly more difficult to predict the energy demand than the energy supply from a PV solar panel.
On the contrary, conventional generation such as CCGT / coal / nuclear power plants are intermittent in the sense that they can fail (and are indeed not generating about ~10% of the year due to maintenance / technical issues). Recent blackouts in California were blamed on the renewable supply – what should be noted is that California has overbuilt CCGT generation and much of the blackout was actually caused by two CCGT power stations turning off. PV rarely encounters technical issues that lead to sudden generation loss – the predictability of power from PV panels is actually astoundingly good. There are also renewable energy approaches that can store energy longer-term (thermal solar, hydro) – economics of these in the US are a different discussion.
In terms of supply-demand matching conventional generation can only react in a matter ~15 minutes to any supply shortage. Increase in electromobility will lead to advent of ‘fast grid regulation’ whereas the charging cars can check the grid frequency as they are charging (in fact – they already do that) and if the frequency falls below 60Hz they can slow charging down / if the frequency rises above 60Hz they can preferably charge. Similarly, they can deploy energy to the grid at night when not in use. Incentive to do that is a matter of energy market regulation, but it is not particularly complicated. These systems also offer much faster frequency regulation (check virtual power stations) than other systems.
If we are discussing the economics aspect of this entire issue – I recommend you look at the ‘2035 report’ published by Berkeley in June – it discusses an economically neutral pathway to 90% less CO2 emissions by 2035. Complete decarbonisation is quite possible by 2050.
I would be happy to discuss this further – but I am absolutely knackered after an infinitely long session at the APS-DPP conference. I also want to say that I am a big fan of your blog and found your discussion of Noether’s theorem a few years back in London quite interesting.
Actually, I will add that nuclear power is hardly ‘on-demand’ – it is always on unless you give it a few months notice to turn off, it’s refueling (every few years), or if it malfunctions. In the UK the government had to pay wind farms to disconnect during the COVID19 lockdown as the energy supply was far higher than the demand (it fell ~10-20% if I remember correctly). Nuclear could not just switch off their generation at a short notice. Energy over-supply causes much the same issues as energy under-supply – frequency of the grid rises, generators can disconnect, currents can flow in the wrong directions.
Latest (2021-01-19) information on how they are modelling what will happen in ITER:
https://phys.org/news/2021-01-realistic-iter-tokamak-magnetic-fusion.html
“To facilitate the design and operation of the ITER tokamak, scientists worldwide have been conducting what are known as nuclear analyses, which are aimed at theoretically examining its outcomes and potential.
So far, nuclear analyses based on data gathered by the ITER reactor have relied on detailed but partial models that only represent specific parts of the tokamak.
…
“Due to the computational limitations of a couple of decades ago, the ITER neutronics community worldwide, including ourselves (the TECF3IR research team at UNED), have so far been working using partial models of the ITER tokamak,” Rafael Juarez, one of the researchers who carried out the study, told Phys.org. “Since then, however, computer power has evolved significantly. Furthermore, in recent years, the computational codes that we use have undergone advances as well, some of them enabled by TECF3IR.” “
Am I am posting too much on this topic?
If not, here is an article suggesting the ITER may have problems:
“Potential design problems for ITER fusion device”
2021-01-22
https://www.nature.com/articles/s41598-021-81510-2
“A key obstacle to such design is the performance during abnormal events including plasma disruptions and so-called edge-localized modes (ELMs). In these events, a massive and sudden release of energy occurs quickly, due to loss of full or partial plasma confinement, leading to very high transient power loads on the reactor surface boundaries. A successful reactor design should tolerate several of these transient events without serious damages such as melting and vaporization of the structure. This paper highlights, through comprehensive state-of-the-art computer simulation of the entire ITER interior design during such transient events, e.g., ELMs occurring at normal operation and disruptions during abnormal operation, potential serious problems with current plasma facing components (PFCs) design.”
No, Keith, you’re not posting too much on this topic! It’s very interesting to me, and I don’t have enough time to research it myself. I sometimes get grumpy when people post comments about W, Y, and Z on an article about X, but you’re not doing that. At least in my mind, ITER is close enough to SPARC that anyone reading about SPARC would be interested in ITER’s triumphs or difficulties.
So thanks.