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.