For MIT scientist Dennis Whyte, it’s a moment he’s been waiting for nearly his entire career.
Officials in the Department of Energy on Tuesday are scheduled to announce “a major scientific breakthrough” that he and his colleagues expect will show that the long-awaited promise of nuclear fusion — considered the holy grail of unlimited clean energy — is no longer hypothetical.
The announcement is expected to reveal that researchers at the Lawrence Livermore National Laboratory in California have produced a fusion reaction that yields more energy than it takes to create, something that has eluded scientists since at least the 1950s. The breakthrough was first reported by the Financial Times.
“This is a really significant development,” said Whyte, director of MIT’s Plasma Science and Fusion Center. “It’s like waking up in a different world.”
For decades, scientists have been trying to harness the energy that powers stars, a complex, atomic-level process known as nuclear fusion, which requires heating a plasma fuel to more than 100 million degrees Celsius and finding a way to contain and sustain it.
In theory, fusion could yield inexpensive and unlimited zero-emissions electricity, without producing any significant radioactive waste, as fission does in traditional nuclear power plants.
Scientific and engineering hurdles have long made that possibility a distant promise. But advances last year at MIT and elsewhere, as well as a growing number of well-financed companies developing the technology, have led some to suggest that fusion could be powering grids within a decade.
The breakthrough at the Livermore lab reportedly occurred at its National Ignition Facility, which uses the world’s largest lasers to test nuclear weapons. Whyte and others said the experiments found the fusion energy generated exceeded, by small amounts, the energy that started the reaction.
With few details available on Monday about the experiment, Whyte and others who are trying to commercialize fusion technologies tempered their enthusiasm.
“We need to see more of the data,” he said. “Understanding the details is very important.”
They also noted that producing electricity on a commercial scale still would require much more research.
“It’s very exciting, but we’re not all the way there,” Whyte said. “I will be really excited when we put the first watts on the grid.”
Others were skeptical about the value of the findings for real world uses.
Edwin Lyman, director of nuclear power safety at the Cambridge-based Union of Concerned Scientists, called the potential applications of the research “impractical.”
“This is not a technology that’s going to yield any practical source of electricity generation in the foreseeable future,” he said. “The array of technical challenges remains formidable.”
Others questioned whether the energy produced really exceeded the amount of energy that went into the reaction, noting the researchers aren’t accounting for the energy it took to operate the lasers.
“This creates the false appearance that the device has produced net energy,” said Steven Krivit, author of books such as “Fusion Fiasco” and “Hacking the Atom.”
But scientists who have spent years studying fusion called such critiques misleading.
Mike Campbell, who recently retired as director of the University of Rochester’s Laboratory for Laser Energetics, one of the world’s leading centers for fusion research, said the experiment was only meant to show that the plasma in the fusion reaction could generate more energy than it consumed.
He acknowledged that fusion power plants are unlikely to be generating electricity soon, but he compared the breakthrough at the national lab to what the Wright Brothers did in Kitty Hawk, N.C.
“They showed that a heavier than air machine could get off the ground; they weren’t designing a 787,” Campbell said. “They showed that air travel was possible, if you could power it.”
He added: “Once the science proves that something can work, you can develop much better technologies. Engineers can produce miracles.”
The first efforts to harness fusion energy came in the 1950s when Soviet physicists designed something they called a tokamak, a doughnut-shaped machine that could confine a super-heated plasma using powerful magnetic fields. The machines did what they were designed to do — fusing the atomic nuclei of hydrogen isotopes to create helium, yielding energy as a byproduct — but they also required massive amounts of power.
Over the years, there have been government-led efforts to address that problem and other challenges, such as the multibillion-dollar International Thermonuclear Experimental Reactor, known as ITER, which the United States and other countries are building in southern France to generate 10 times more power than it takes to generate a fusion reaction.
With that project moving slowly and at great expense, private efforts have sought to prove that fusion could be done much more cheaply, quickly, and with a much smaller footprint. There are now dozens of companies trying to prove that fusion can be a practical power source, most of them established in the past decade, according to the four-year-old Fusion Industry Association.
Among them is Commonwealth Fusion Systems, an MIT spinoff in Cambridge, which in recent years has raised some $2 billion from investors such as Bill Gates, Google, and a host of private equity firms. The company was cofounded by Whyte, whose team last year used low-cost materials to produce the most powerful magnetic field of its kind on Earth, a critical component of a fusion reactor.
The company, which just this week began moving into its new headquarters on a former Superfund site in Devens, is using Whyte’s research to build a prototype of a specially designed fusion reactor called SPARC, which aims to produce more energy than it consumes, in 2025.
If they succeed, Commonwealth Fusion Systems plans to start building their first power plant several years afterward. Ultimately, company officials say, their goal is to help build 10,000 200-megawatt fusion power plants around the world, enough to replace nearly all fossil fuels.
Bob Mumgaard, the company’s chief executive, called the breakthrough at the Livermore National Laboratory “a great moment for fusion.”
“These exciting results are the culmination of years of work demonstrating that fusion science is worth the investment,” he said. “This is an important validator for . . . the fusion industry.”
Other proponents of fusion said they hoped the breakthrough would lead to greater public and private investments.
US Representative Lori Trahan, a Westford Democrat, urged her colleagues to allot more money for fusion research, calling it “essential to solving the energy problems we face today.”
“With every dollar we invest in fusion energy, we speed up the existence of fusion energy on the grid and help guarantee that our children and grandchildren inherit a livable planet,” she said in a statement.
David Abel can be reached at firstname.lastname@example.org. Follow him on Twitter @davabel.
David Abel can be reached at email@example.com. Follow him on Twitter @davabel.