In a quiet and unassuming industrial park south of the city of Oxford, there's a technological revolution going on.
From the outside, Tokamak Energy's premises look much the same as its neighbours in this semi-rural setting in the Oxfordshire countryside.
But inside, you are stepping into what the company hopes will be a major part of power generation in the coming decades.
While solar energy harnesses the power of the Sun, fusion energy is the power of the Sun.
Fusion is the process where the nuclei of two lighter atoms (usually hydrogen) collide and fuse to form nuclei of heavier atoms, usually helium.
In nature, this process takes place within stars and releases vast amounts of energy.
Fusion not fission
Proponents of fusion say it produces no greenhouses gases or long-term radioactive waste and its source is abundant, as the hydrogen used can be extracted from seawater.
Fusion is everything that fission is not, its supporters claim.
Fission is what happens at nuclear power stations, where the energy is gleaned from the splitting of atomic nuclei.
Aside from radioactive waste, safety has proved to be an issue at nuclear power stations — just think of Chernobyl, Three Mile Island and Fukushima.
But with fusion reactors there is no risk of meltdown — you can literally just pull the plug out. Achieving a fusion reaction is much more difficult than fission. However, stopping a fusion reaction is easy, whereas with fission it is the opposite.
Controlling fission reactions and using the associated heat to produce electricity at power stations is the goal of government-funded fusion laboratories and companies such as Tokamak Energy.
Tokamaks are the leading design for practical devices seeking to harness fusion energy. Using powerful, high-temperature superconducting (HTS) magnets, they are built to hold the plasma, within which the thermonuclear reaction happens, in the shape of a torus.
First conceived by Soviet scientists back in the 1950s, the word 'tokamak' is the transliteration from a Russian acronym that stands for 'toroidal chamber with magnetic coils'.
Tokamak Energy's genesis goes back to 2009, when the company's co-founder and current executive vice chairman, David Kingham, had a conversation with two scientists at Culham Campus, near Oxford, home of the United Kingdom Atomic Energy Authority (UKAEA).
It was a conversation that sparked the foundation of Tokamak Energy and its focus on spherical tokamaks.
“They felt the spherical tokamak was going to be more efficient and more relevant for commercial fusion energy,” said David Kingham.
“And I agreed with them; I could see the advantages of a more compact shape, and, basically reducing the size of the device, so you get a cheaper, quicker development pathway.”
That development pathway brought about the ST25 tokamak and the current ST40 reactor. Last year, the ST40 achieved a 100°C fusion plasma — the highest temperature recorded in a compact spherical tokamak.
But the pathway doesn't stop there. Recently, Tokamak Energy announced that its next generation reactor, which will be twice as big as the ST40, will be built nearby at UKAEA's Culham Campus.
The ST80-HTS aims to keep the plasma stable for longer, creating the conditions necessary to take fusion power closer to commercial viability.
The ST80-HTS should be ready by 2026, beyond which the next step is a fusion pilot power plant, at the moment a project called ST-E1. That will demonstrate the capability to deliver 200 megawatts of electricity into the grid in the early 2030s.
While the UK government has selected a site to base a spherical tokamak reactor in Britain, Mr Kingham believes there could be many other countries interested in acquiring one.
“International collaboration could work very well in this area,” he said.
“And, of course, we look to UAE and we think the Barakah fission power plant has been delivered quite exceptionally on time and on budget through decisive leadership of the country.
“And that might mean it’s a very good location for a fusion pilot plant, because if the top-down support is there, then things that take a long time in western countries could be relatively easily overcome and get right down to the proper safety precautions and so forth.”
The challenge of fusion technology is scalability. Getting from an ST25 to a grid-ready, working spherical tokamak power plant is not merely about making everything twice as big at each step. New technology needs to be developed, alongside new manufacturing techniques.
“You run into different challenges as you scale up,” said Mr Kingham.
“At the moment, we’re scaling up the physics of the tokamak — we’re confident about that, because we’ve got several data points and we know, basically, how things will scale with size and magnetic field.
“On the magnet side, there’s a different scaling-up challenge, which is that manufacturing technology is going to need to change as the magnets needed get bigger and bigger.
“We know how to do it, we know how to design it, we’ve developed a lot of the manufacturing technology, but we need to turn that from drawings and prototypes into real systems.”
Meet the new boss
While Tokamak Energy is scaling up the size of its tokamaks and magnets, it's also evolving as a business.
Initially, funding came from the UK government's Rainbow Seed Fund and the high-tech engineering company, Oxford Instruments.
But as the commercial viability of fusion moves closer, Tokamak Energy's financial and operational partners range from the UK asset manager Legal & General to the US Department of Energy.
The recent appointment of Warrick Matthews as Tokamak Energy's new managing director and chief commercial officer highlights the firm's business evolution.
He worked for Rolls-Royce for 20 years and most recently was the head of the engineering giant's procurement.
“What I bring here is the partnership experience, the supply chain experience, novel business constructs, some mergers and acquisitions experience into that future as we map it out,” he said.
“If you imagine the curve that got us where we are today and you need to carry that forward, you need industrial partnerships, partners who are also investors in the company, and that’s what I’m working on with the leadership team and the board to map out now.”
Not only electricity generation
With commercial viability comes marketing, customers and an order book. For Tokamak Energy, that could mean a wide range of applications across the world.
For example, the International Energy Agency (IEA) says two thirds of the water produced from sea desalination in the Middle East today is from fossil fuel-based thermal desalination, while the rest is from a membrane-based practice that relies heavily on electricity produced using natural gas.
In total, the Middle East accounts for roughly 90 per cent of the thermal energy used for desalination worldwide, led by the UAE and Saudi Arabia.
“If you take a country like the UAE, and you think, fusion for the future, we’re thinking, 'yes, grid electrical power',” said Mr Matthews.
“But the one I’m really intrigued about in the UAE is the desalination of water. Fusion could couple extremely well with a desalination facility, and the heat that’s produced, without having to convert to electricity, can be used in the desalination process.”
'Saving polar bears'
The scalability and commercial viability of tokamak fusion energy is still years away. But while there are challenges, the industry has a road map that looks to the future.
Mr Matthews uses commercial space flight as an example of scientific achievement that once seemed improbable but are now well under way with the likes of Space X and Virgin Galactic.
The mission of Tokamak Energy and, indeed, all fusion firms, is to create cheap, limitless and, most importantly, zero-carbon energy.
“The first day I was here, I shared a good luck card one of my daughters had drawn for me,” Mr Matthews said.
“It said on it ‘Daddy, we’ll miss you when you’re in Oxford, but at least you’re saving polar bears’, with a picture of a polar bear and an iceberg.”
