Clean energy from fusion will be more than a clever gimmick

Earlier this month, the Joint European Torus, a research centre in the UK, announced a record for the highest sustained energy from fusion. Photo: Jet

Q is familiar to us as the ingenious MI6 inventor, frustrated with James Bond’s repeated destruction of his gadgets. But Q may one day be also well-known as the energy yield from a fusion reaction — the source that powers the stars, and may light up Earth too.

Unlike traditional nuclear fission, fusion brings atoms — usually isotopes of hydrogen — together rather than splitting them. It has many advantages. The process is zero-carbon, uses common fuels with very high energy density, is inherently safe with no risk of meltdown or weapons proliferation, and produces very little high-level radioactive waste.

But fusion is technically enormously challenging. Depending on the approach, it can require a millionth of atmospheric pressure, temperatures of 100 million degrees Celsius and magnetism 280,000 times the Earth’s natural field to contain the plasma of ionised hydrogen. The flow of neutrons from the reaction generates the heat to be captured as useful energy, but damages the materials containing it. Components the size of a six-storey building must be assembled with precision of less than a millimetre.

The reaction has to be sustained long enough to provide useful energy that exceeds the electrical power that started it, and hence the importance of Q, the ratio of energy input to output. A practical power reactor needs to achieve at least five, at which point fusion becomes self-sustaining.

Earlier this month, the Joint European Torus (Jet), a research centre in the UK, announced a record for the highest sustained energy from fusion. Jet’s Q value was 0.33 — for five seconds, an aeon in fusion time. In August, the US National Ignition Facility, or Nif, reached 0.7 from laser-initiated fusion over a shorter period.

Nif’s energy yield has improved a thousand-fold over the past decade and they said they achieved “ignition” in further work in November. The Iter reactor under construction in France by an EU-led international consortium hopes to begin experiments in 2025 and achieve a Q of 10.

Researched since the 1950s, fusion’s history as a practical energy source has been a saga of fitful interest and enthusiasm, with genuine progress disguised by failure to meet optimistic predictions. Now that seems to be changing.

New optimism comes from progress by government-funded institutions such as Jet, Nif and Iter, and advances in materials science. Superconducting magnets and computer modelling, and a wave of private companies, including innovative start-ups, with new approaches, also bode well for its success.

US oil major Chevron invested in a fusion start-up, Zap Energy, in 2020. Helion, which extracts energy directly from the fusion reaction rather than its heat, raised $500 million in November, which was a record at the time, to expand its development.

That was surpassed in December when investors put a remarkable $1.8 billion into Commonwealth Fusion Systems (CFS), whose backers include oil companies Eni and Equinor, and Bill Gates’s investment vehicle Breakthrough Energy. CFS is trying to commercialise fusion based on high-temperature superconducting magnets.

The diversity of approaches and the large funding now available give hope of yielding at least one viable system. Helion wants a working demonstration plant by 2024, while CFS hopes to have a commercial unit up and running by the early 2030s.

Helion estimates it could generate electricity for 1 US cent per kilowatt-hour. That is about the level of the current cheapest solar power — but from a 50-megawatt system the size of a shipping container, and available regardless of daytime, weather and seasons. It is well below the costs of coal, gas or traditional nuclear fission.

Such a compact system could power ships or perhaps even planes and spacecraft. It could provide electricity and heat for industries, to make hydrogen, to desalinate water and to suck excess carbon dioxide from the atmosphere.

Of course, we should not bet our energy and climate future on fusion. To meet global net-zero carbon goals around 2050, electricity generation would have to be net-zero by 2040. That does not leave much time for fusion to contribute.

But we may find ourselves struggling in 2040 to deliver reliable, affordable, zero-carbon grids worldwide, particularly to cover the last 20 per cent or so of demand that becomes very costly with renewables. This includes, for instance, long cold but windless winter spells in northerly climes, or cold fronts that sweep in and raise heating demand hugely within hours.

The scale of minerals and biofuels to build a renewable-dominated energy complex is enormous, likely to raise costs and cause environmental damage. The more options we have, like carbon capture and storage, and advanced nuclear fission, the better the chance of building a robust, cost-effective system that overcomes unexpected roadblocks from a more narrow-minded approach.

New energy demands will emerge by mid-century, such as ubiquitous autonomous vehicles and drones, hypersonic intercontinental travel, widespread personal robots, and commonplace space tourism and industry. To meet global climate goals, a forest of machines capturing carbon dioxide from the air in 2100 would use energy equivalent to more than half of all global demand today.

Low-cost reusable rockets are opening up the frontiers of space, making large-scale expeditions and even settlements in orbit or on the Moon and Mars plausible. We have found almost 5,000 extrasolar planets, including three around our Sun’s nearest neighbouring star, Proxima Centauri. A robotic fusion-driven mission might get there within a few decades — not a prospect for today, but perhaps a realistic dream for late this century.

There is a future beyond the climate challenge. Very cheap, abundant clean energy from fusion will be more than a clever gimmick. Only our imagination and a little humility limits what we could achieve.

Robin M. Mills is chief executive of Qamar Energy and author of The Myth of the Oil Crisis