Supporting fusion energy development in the UK

The UK is at the forefront of fusion energy research and development, hosting the EU’s Joint European Torus (JET), the world’s leading fusion machine, as well as a growing ecosystem of public and privately funded initiatives. The UK government recently announced funding of £220m for the UK Atomic Energy Authority, which hosts JET at its Culham site in Oxfordshire, to develop a concept design for a practical electricity-generating fusion device. Oxfordshire is also home to two of the world’s most promising privately funded fusion start-ups in the form of Tokamak Energy and First Light Fusion.

But the fusion landscape in not limited to the headline-grabbing drive to generating energy from a fusion device. Multiple enabling technologies are also required, from control systems to materials, from diagnostics to robotic handling. UKI2S was the founding investor in Tokamak Energy a decade ago and more recently has started to fund some of the most promising companies addressing the enabling technologies. Here we look at three of our portfolio companies, Tokamak Energy, Luffy AI and Qdot which are all playing a vital part in making the promise of fusion energy a reality in the future.

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Tokamak Energy

Tokamak Energy was founded by scientists from the Culham Laboratory, the world-leading centre for magnetic fusion energy research.  To achieve its mission to change the way the world generates power, Tokamak Energy’s target is to demonstrate the feasibility of fusion as an energy source by 2030.  Now employing over 140 people, Tokamak Energy is one of the largest private companies in the world working in the sector and has raised over £117m private investment to date since UKI2S’ founding investment, with a further £12.5m of grant funding, including from the UKI2S Innovate Accelerator, a joint initiative between UKI2S and Innovate UK (IUK).

According to Tokamak Energy Executive Vice-Chairman, David Kingham, “the next big goal is for our ST40 compact tokamak to become the first privately-funded fusion machine to achieve the temperatures required for fusion, 100 million degrees C. This milestone, together with other key experiments planned for next year, will prove a that high field spherical tokamak is the best route to accelerate development of commercially viable fusion power.”

David also has some valuable views on the wider subject of the UK’s ability to continue as a world leader in fusion energy development. He believes that to succeed we need to build an ecosystem of suppliers and R&D partners. David explained that, “a fusion ecosystem has become a deliberate strategy for the UK. It didn’t start out like that but the JET at Culham has been operating for over 40 years and in recent years other companies have started to emerge to support vital aspects of the supply chain.” 

Collaboration is essential to solving multiple technical challenges

We spoke to Tim Bestwick, Chief Technology Officer & Director Strategy, Communications and Business Development at UK Atomic Energy Authority who explained that “fusion energy holds enormous promise as a future low-carbon energy source, but delivering practical fusion energy is extremely technically challenging. This is partly because there is not one single technical issue to be solved, but rather multiple areas of technical challenge to be addressed. There is no doubt that addressing these challenge areas requires deep and extensive collaboration – in particular between the national and international programmes that have dominated fusion R&D for decades and the innovative commercial businesses that will be key to delivering fusion energy at scale. It is great that this fusion ecosystem – the ‘UK fusion technology cluster’ – is now beginning to flourish in the UK, which should really accelerate the pace of fusion energy development.

At UKI2S, we entirely agree that this ecosystem is essential for the creation of a sustainable fusion industry in the UK and while we continue to support Tokamak Energy we are also investing in other companies that are helping to form the supply chain including Luffy AI and Qdot. 

Luffy AI

Luffy is a spin-out from UKAEA, and is still based on the Culham site, though their focus is not originally derived from the founders’ work on fusion. Luffy was founded to develop novel AI technologies capable of exhibiting neuroplasticity (which roughly translates as the ability to modulate the computational process, i.e., machine behaviour, in real time). This gives the network controller the ability to adapt and learn the characteristics of the hardware it controls, contrasting with most machine learning that relies on large datasets and huge computational power to crunch through millions of possible scenarios and outcomes. This offers huge potential in areas where mainstream AI techniques have struggled including performance variability and drift in machinery.

The AI technologies being developed at Luffy have significant value beyond the fusion community. Alex Meakins, CTO of Luffy, said “the neural network system we’ve developed allows our networks to adapt in real time and exhibit a much higher capability per Watt than conventional neural networks.” Adaptive neural networks will in turn enable new exciting applications in robotic motion control, industrial process optimisation and IoT devices. Matt Carr, CEO of Luffy, continued “this could be a game changer for applications with restricted power envelopes, such as UAVs and the internet of things.” Luffy is currently developing technology demonstrations in the UAV and robotics space, but also looking to stay active in the growing ecosystem of technology companies pushing fusion to maturity.


Qdot is a spin out from Oxford University’s Thermofluidics Institute. The company was formed in 2019 to exploit the know how developed during research on cooling systems for fusion energy devices. One of the key technological challenges for fusion is to handle the extraordinary heat exhaust from such machines where the temperatures at the centre of the device can reach 150 million degrees C, and even across a near perfect vacuum the  heat loads of the exhaust particles are some  10,000 times greater than the power from the Sun’s rays. This is the typical heat load that some components within a commercial fusion reactor will have to withstand for years at a time! Qdot’s understanding of heat transfer and fluid dynamics is being used by Tokamak Energy to solve this problem and help usher in the age of fusion power.

The idea behind the formation of the company is quite simple: if you can deal with heat loads of millions of degrees then surely the same techniques could solve heat management problems elsewhere. There is no shortage of potential applications, from improving battery performance to rocket nozzles. The most attractive and immediate challenges are probably those in the battery world, where the widespread adoption of EVs is hampered by charging times, anxiety over battery life and the cost of batteries. And a second generation of battery technologies will be required for electric aircraft, where rapid charging is critical; nobody is going to buy an aircraft that has to wait hours to recharge before making a return journey. The company is using the funding from UKI2S and grants from Innovate UK and the Faraday Institution to re-imagine battery packs from the cell-level up, with thermal management at its core.  This enhanced thermal management is allowing Qdot to greatly increase battery pack power densities, making extremely fast charging – adding 200 miles of range in just 10 minutes for ground vehicles – possible. This makes mid-journey charging stops quick and convenient, increasing the effective range of a vehicle using a smaller battery pack. Since the batteries make up the lion’s share of the cost of an electric vehicle, this also brings down the cost to OEMs and consumers.

The same approach looks promising for the emerging electric aircraft sector. And, of course, there is also considerable work to be done in nuclear fusion, where it all started.

The plethora of supporting technologies, of course, has echoes of the spinoff technologies from the space race, delivering additional benefits long after the main project has finished. Although probably less complex than landing a man on the moon the pursuit of fusion is arguably more important since it provides the world with an inexhaustible source of safe and economic energy that could yet save the planet.  The additional benefits we might see from applications of enabling technologies in other areas just make the journey even more interesting and rewarding.