Successfully producing energy from fusion always has been a moonshot – but it is one that investors, including an unlikely millionaire celebrity, say they are on the brink of achieving.

A dimpled chunk of dark-coloured iron sits on Richard Dinan’s desk at his office in central London. He insists it is not just an expensive paperweight.

This malformed lump, forged in the heart of a star billions of years ago, is a meteorite. It is also what gave Dinan the idea for his latest business venture.

The millionaire, who found fame as a playboy entrepreneur on the reality television show Made in Chelsea, runs a discount card business and 3D printing company. Now, however, he is eyeing something far more ambitious: nuclear fusion.

For decades, fusion power has been an almost fanciful dream of those hoping to crack the world's energy problems. Nuclear fusion powers the stars and burns in the heart of our own Sun. Here on Earth, it could provide an almost limitless, safe and clean source of energy.

But it has remained frustratingly out of reach. Physicists have been attempting to turn nuclear fusion into a viable power source since the 1950s. There is a joke in the energy community that the world is just 30 years away from benefiting from nuclear fusion power… and that it always has been and always will be.

Fusion is the process of fusing the nuclei of two small atoms together to form a larger one. It takes huge amounts of energy to cause this to happen, but when it does, even greater amounts of energy can be released. Achieving fusion itself was never really the problem – humans have been able to trigger thermonuclear fusion reactions ever since the first hydrogen bomb was set off in 1952. The real challenge has been how to harness the awesome energy it releases.

Achieving fusion itself was never really the problem

Governments around the world have ploughed billions into fusion projects, building vast machines which heat gas to temperatures many times that of the sun. There have been some successes. The Joint European Torus experiment known as Jet, at the Culham Centre for Fusion Energy in Oxfordshire, England, demonstrated in 1991 that it is possible to release power from nuclear fusion in a controlled environment. It released 16 megawatts (MW) of power – enough to boil 6,400 kettles. But it required 25 MW of power to trigger the fusion reaction.

This step, however, led 35 countries to commit to building a new, larger reactor based on the same design in the south of France. Known as the International Thermonuclear Experimental Reactor (Iter), its aim is to generate more energy by triggering a reaction that will sustain itself.

The project has been hit by almost a decade of delays and overspending. Initially slated for 5 billion euros (£4.3 billion), the cost has nearly tripled to an estimated 14 billion euros (£12 billion).

Capital idea

As a result, private investors including Dinan believe they can edge into the field. “Technology has moved on considerably since Iter was designed,” Dinan says. “I have no new physics for the world. My trick is that I can build technology quickly and cheaply.”

I have no new physics for the world. My trick is that I can build technology quickly and cheaply – Richard Dinan

Dinan’s plan is to build smaller, more compact reactors that will cost a fraction of that needed for Iter. Like the other private ventures trying to get onboard the fusion bandwagon, he argues that as nimble enterprises, they are better placed to solve these problems more quickly than big, expensive public projects. He believes advances in supercomputing and rapid 3D printing technologies will allow him to build reactors in far shorter timescales, too. With £200 million he hopes to raise from investors, he plans to build two reactors within the next seven years.

Although it would be easy to dismiss Dinan as a dreamer, his startup Applied Fusion Systems is one of a growing number of firms investing in the promise of fusion. In the UK alone, there are at least two other companies trying to produce commercial nuclear fusion power stations. And as BBC Future reported last year, in the US, several projects have received the backing of wealthy technology billionaires including Amazon’s Jeff Bezos, Microsoft co-founder Paul Allen, Paypal co-founder Peter Thiel and former Google vice president Mike Cassidy.

After all, with the prospect of climate change making fossil fuel use unsustainable, there is a hunger for other sources of power. But renewable sources like solar and wind are not yet fully reliable and nuclear fission remains unpopular because of the harmful waste it produces.

“I’m not surprised there are an increasing number of private investors willing to put money into fusion,” says Ian Chapman, head of the UK Atomic Energy Authority and Culham Centre for Fusion Energy. “You have this source of energy that has incredibly high yield, no radioactive waste, it requires little land use, has an effectively inexhaustible fuel supply and is continuous.”

In other words, there is a lot of money that could be made.

When Iter turns on – currently scheduled to happen in 2025 – it is expected to have the capacity to produce 500 MW, 10 times the energy needed to trigger a fusion reaction. But whether that actually will happen remains to be seen. “We are still at the stage of trying to demonstrate it is possible to get more power out than you put in, and that it can be done on a commercial scale,” says Chapman. “Private industry is still someway behind that, as far as we can tell.”

If Iter is successful, however, it will be the start of a fundamental shift in the world’s energy landscape. Dinan, like other companies in the industry, believes those who already know how to build reactors will reap the greatest rewards.

“When Iter works, the appetite for fusion will be huge,” he says. “It will be the biggest innovation of our generation and it is going to be companies that are starting in the fusion business now that others will come to.”

Powering on

Dinan’s approach to cracking fusion draws on research conducted by scientists at Culham over the years. Dinan’s company is planning to build a spherical tokamak based on the design of an experimental reactor at Culham, the £40 million Mega Amp Spherical Tokamak (Mast). Tokamak reactors work by heating hydrogen atoms to the point where they form a plasma – a super-hot, electrically-charged gas. Powerful magnetic fields levitate this glowing ion soup and help squeeze the plasma together, increasing the chance of collisions that lead to fusion.

The Mast design is a squashed, rounder version of the tokamak reactor being built for Iter, and theoretically should require less energy to contain the fusion reaction.

But achieving the conditions for fusion means heating two types of hydrogen, known as deuterium and tritium, more than 100,000,000C – six times the temperature at the centre of the Sun. Heating the fuel takes huge amounts of energy. Even more energy is required to power the magnets to keep this resulting plasma away from the walls of the reactor, which easily could melt at these temperatures.

Mast has generated plasmas with temperatures of up to 23,000,000C inside its 4m-wide stainless steel reaction vessel, but still falls short of the temperatures needed for full fusion.

“We want to build several of these and test out our ideas,” says James Lambert, head of operations at Applied Fusion Systems. “It is unlikely that our first reactor will produce a net energy gain, but we are aiming for an electrical output of 100 MW or just below.”

Lambert says simulations run on supercomputers will help model how the plasma will behave inside the reactor, speeding up the design process. In the meantime, they are working on methods to 3D print the components, allowing for a faster testing schedule. “Plasma behaves in unpredictable ways,” says Lambert. “Now that the price of supercomputing has plummeted, it is giving fusion researchers the ability to test their ideas before building them.”

Now that the price of supercomputing has plummeted, it is giving fusion researchers the ability to test their ideas before building them – James Lambert

Applied Fusion Systems are entering an increasingly competitive market. One of the oldest fusion energy companies is Oxfordshire-based Tokamak Energy, established in 2009. They are also looking to use the spherical tokamak design to create small-scale fusion reactor power stations.

“If you go back 20 years, people were still thinking about creating fusion reactors that would generate a large base load with several gigawatts of power,” says David Kingham, Tokamak Energy’s chief executive. “Now they are looking at a much more distributed power supply where smaller power plants on the 100 MW scale are more attractive.”

Tokamak Energy is on the verge of completing their third test reactor – a 2.5m-tall device swathed in copper magnets. They hope to generate plasmas heated to 15,000,000C later this year; by 2019, they aim to increase that temperature closer to the 100,000,000C needed for fusion.

“Enough is known about the physics to get these machines to work,” says Kingham. “It is getting down to a series of engineering challenges now.”

A spin-out company from the University of Oxford, First Light Fusion, is taking a different approach. It is hoping to exploit a technique called inertial confinement fusion, where lasers are fired at a pellet of fuel to compress it until the atoms fuse. However, this technique only ever has been able to achieve about one-third of the conditions needed to ignite a fusion reaction.

California dreaming

Despite this setback, fusion has captured the imagination of wealthy Silicon Valley and internet billionaires looking for their own version of the moonshot. One example is Paul Allen, co-founder of Microsoft, who has helped bankroll California-based Tri Alpha Energy. Over the past 20 years the company has developed a reactor that fires beams of high-energy plasma at each other inside a reaction chamber. Rather than using isotopes of hydrogen as the fusion fuel, they are looking to use a form of boron instead – but this will require far higher temperatures to start the reaction.

Another approach is being taken by Canadian firm General Fusion, backed by Amazon chief executive Jeff Bezos. A 3m-wide reaction chamber bristles with 220 pistons which will create a shockwave when they fire simultaneously. This will send a spinning vortex of liquid lead and lithium crashing into two rings of plasma that have been accelerated towards each other.

Still, significant challenges remain.

“In the middle of these reactors you have a fuel that is 10 times hotter than the centre of the Sun,” says Chapman. “You have to have stable and safe way to get the exhaust heat escaping from the plasma out of the reactor without melting any parts of it.”

A fusion reactor will be the most intense source of neutrons on Earth – Ian Chapman

Fusion reactions also release subatomic particles called neutrons which fly out and smash into the walls of the reactor, taking a toll on even the toughest metals. “A fusion reactor will be the most intense source of neutrons on Earth,” says Chapman. “We need to be able to understand how these will affect the materials we use to make the reactor. That is complex science.”

Scientists at Culham are working on solutions, including a £30 million upgrade to the Mast reactor which uses new configurations of magnets to distribute the heat over a wider area. Meanwhile, Dinan already is looking at a number of sites on the outskirts of London that he hopes will be suitable for his reactors.

“It is very exciting to be part of this field right now,” says Chapman. “It feels like we are finally entering the era when we will see the promise of fusion being delivered.”

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