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Nuclear Hitchhiker

Fire fusing through a generator

The roaring twenties for fusion energy?

Fusion 13th April 2022

Author: Emre Yildirim, PhD student, The University of Manchester.

Touted as the Holy Grail, or cited as another big science big bust, nuclear fusion has its lovers and haters. While comments rain from all sides as headlines come out regarding recent discoveries and new cash injections, it is time for us stop and let the work speak for itself as this new decade proves to be the biggest in the history of this scientific venture and will possibly decide the fate of this technology.

While larger projects such as ITER push delivery targets into the 2030s, this decade will be the turn of the private fusion ventures to take centre stage with a plethora of different demonstration devices opening in the middle of the decade. The target of these will be proving the viability of their devices in terms of producing a Q factor greater than one – where the energy used to heat the plasma is less than that produced by the fusion reaction.

So what are the players looking to heat up this decade? Helion (planned demonstration plant completion in 2024), Commonwealth Fusion Systems (2025), and General Fusion (2025) all have their demonstration plants opening this decade with TAE Technologies also suggesting their reactors will be ready for commercialization by the late 2020s. These four companies will give us the first look into not only private demonstration plants, but demonstration plants in general. While there are some people betting big already (see $1.8 billion for Commonwealth Fusion Systems), the success of these plants would glue the eyes of the world firmly on fusion.

What does success look like? Success for the individual companies is obvious, net energy gain, but for fusion as a technology, the number of projects and their diversity means success can be seen in a multitude of ways. Of the four companies mentioned, Commonwealth Fusion Systems is the only one utilising the more conventional tokamak form, often pursued in the public sector (see ITER and STEP). The others look to utilise less-traditional concepts that combine various technologies. General Fusion looks to use large pistons to compress the plasma while TAE technologies look to use different magnetic geometries in what is called a field-reverse configuration.

Helion is completely different, throwing out the classic steam turbine to use the plasma to directly drive current in surrounding coils. Then there is fuel, classic deuterium and tritium is on display (Commonwealth Fusion Systems and General Fusion) but helium-3 is the choice for Helion and proton-boron fusion is favoured for TAE technologies. While the physics behind these and the reasoning behind their choice will not to be described here, this should demonstrate the assortment of technologies on offer.

This cocktail of methods leads to several scenarios for success:

  • All demonstrate a Q>1
  • Some demonstrate Q>1 some do not
  • All fail to demonstrate commercial viability

The first scenario is clearly the optimal one. With a multitude of options on offer it would pave the way to a future of where variety of machines with different advantages over each other being on offer. Depending on the need of the country or region they are powering, different approaches would be favoured over others. This would further allow more risks to be taken in academic ventures, which so far are mostly tokamak-centric, and credence to tailoring work to the needs of these new machines would be given.

Scenario two, where only some of the reactors work, could go one of two ways. Conventional tokamak designs outperforming others would lead to an ‘all-in’ on the tokamak design and ratify many government choices to favour this design. This would lead to less funding for less conventional designs. While focus on one design could accelerate this specific concept, in many industries, variation leads to stronger technology and therefore such moves may hamper future innovation. A scenario where the less conventional designs shine through would lead to a large rethink on some of the biggest scientific projects we have undertaken. The inertia and size of these projects mean they will still be completed but sceptics of these projects would feel justified in their critique and opposition to these could grow affecting future scientific endeavour.

The final scenario, where all fail to demonstrate commercial viability, is not the end for the technology but would be a huge hit to future investment and would affect many other fusion start-ups worldwide. Greater scrutiny on large-scale public experiments and questions of the importance of fusion going forward would be raised. A managed response by the involved companies would seek to save the reputation of the technology but it certainly would do little to persuade those who joke about it always being thirty years away – giving the technology another thirty might not seems so appealing.

Overall, this decade is an important one, and while this is only the first bite of the cherry, a time-sensitive problem such as climate change and future energy security may lead to people looking elsewhere for their saviour. A decade in which we see some of these milestones being reached would be a huge accomplishment and one of the most ground-breaking scientific achievements in the energy sector and beyond. So while some of these scenarios could lead to rocky times in the industry, the potential for success is too great to ignore. A truly exciting time for fusion, and possibly one of the most ground-breaking for energy as a whole.