Fuelled by venture capital and a lot of hope, alternative fusion technologies are heating up.
To reach one of the world’s most secretive nuclear-fusion companies, visitors must wind their way through a suburban office park at the foot of the Santa Ana Mountains, just east of Irvine, California, until they pull up outside the large but unmarked headquarters of Tri Alpha Energy.
This is as close as any outsider can get without signing a non-disclosure agreement; Tri Alpha protects its trade secrets so tightly that it does not even have a website. But the fragments of information that have filtered out make it clear that the building houses one of the largest fusion experiments now operating in the United States. It is also one of the most unconventional. Instead of using the doughnut-shaped ‘tokamak’ reactor that has dominated fusion-energy research for more than 40 years, Tri Alpha is testing a linear reactor that it claims will be smaller, simpler and cheaper — and will lead to commercial fusion power in little more than a decade, far ahead of the 30 to 50 years often quoted for tokamaks.
That sounds particularly appealing at a time when the world’s leading fusion project, a giant tokamak named ITER, is mired in delays and cost overruns. The facility, being built in Cadarache, France, is expected to be the first fusion reactor capable of generating an excess of energy from a sustained burn of its plasma fuel. But it looks set to cost as much as US$50 billion — about 10 times the original estimate — and will not begin its first fuelled experiments before 2027, 11 years behind schedule.
With ITER consuming the lion’s share of the US fusion-energy budget, fans of alternative approaches have scant government support. But growing impatience with the tokamak technology has spurred the Tri Alpha team and many other physicists in the United States and Canada to pursue different options. Over the past decade and a half, these mavericks have launched at least half a dozen companies to pursue alternative designs for fusion reactors. Some are reporting encouraging results, not to mention attracting sizeable investments. Tri Alpha itself has raised $150 million from the likes of Microsoft co-founder Paul Allen and the Russian government’s venture-capital firm, Rusnano.