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For half a century, scientists—and tens of billions of research dollars—have been chasing the dream of “hot fusion,” the idea of mashing hydrogen atoms together to release vast amounts of clean energy.
For almost all of that time, research has focused on heating a gaseous mix of charged atomic particles to temperatures higher than the sun’s.
Now First Light Fusion, a start-up spun off from Oxford University, has completed its first successful fusion test of an entirely different idea.
In First Light’s fusion chamber, a bullet-like projectile is fired at hypersonic speed at a falling target—about a half-inch, roughly 0.4 centimeters, on a side—embedded with atoms of deuterium, or “heavy hydrogen,” so-called because it has twice the nuclear mass of regular hydrogen.
The target is carefully designed so that when the projectile strikes, the target implodes and sets off collapsing shockwaves that, for an instant, create pressures a billion times higher than normal air pressure.
The shock waves collapse the quarter-inch pellet to barely the thickness of a human hair.
Those pressure waves are strong enough to smash the deuterium atoms together, releasing energy that can be harvested.
The pressure waves accelerate the deuterium atoms to about 157,000 miles an hour, or 252,000 km per second, as they crash together, overcoming nature’s repelling force and making the atoms the fastest-moving things on Earth, the company says.
The imploding pellet then plunges into a container of liquid lithium and a heat exchanger transfers the heat to water, making steam to spin a generator.
Each pellet’s implosion would yield enough energy to power a typical U.K. home for two years, about 6.2 megawatt-hours, First Light has calculated.
An initial commercial plant would deliver about 744 megawatts, about 75 percent as much energy as a typical nuclear power plant but without the toxic waste or the risk of melting down and rendering surrounding lands uninhabitable for years, if not decades.
The electricity’s cost would be slightly higher than solar electricity is today, First Light says.
The company plans a power plant that will begin to produce about 150 megawatts of electricity in the 2030s and cost less than $1 billion to construct, a fraction of the cost of a conventional nuclear power station.
TRENDPOST: We have long expressed skepticism about conventional hot fusion technology, most recently in “Hot Fusion: The Dream – and the Hype – Live On” (22 Feb 2022). A machine that, after 40 years of work, has yet to survive more than a few seconds of operation without succumbing to its own heat, doesn’t seem to have much of a future.
First Light’s clean-sheet approach and that of Australia’s HB11, which we explored in “New Fusion Energy Method Revives Advocates’ Hopes” (2 Mar 2021), could prove to be not only practical, but cheaper.
However, even those technologies are unlikely to yield commercial amounts of power before the 2040s, by which time centralized electric grids will be largely outmoded.
Instead, the new fusion technologies could easily find homes with large manufacturing plants, military installations, college campuses, and other users with high energy demands.