A breakthrough in nuclear fusion may produce "near-limitless energy"

Even long before climate change made it clear that constant burning of fossil fuels was wreaking havoc on Earth's climate, scientists and engineers wondered whether humankind might power our civilization with the same kind of energetic reaction that takes place in the sun. While fusion power, as it is known, is technically not a "renewable" form of energy like wind or solar, it is far more energy-dense. And unlike nuclear fission, which requires politically troublesome and hazardous uranium, nuclear fusion relies on lightweight elements, like hydrogen, which can be extracted from water.

Fusion happens in our sun through the constant collision of light elements like hydrogen, which are smashed together to form heavier elements. When this happens, it releases a burst of energy so powerful that it can fuel stars like our own for billions of years. It is also an efficient process: half of a gram of hydrogen could yield 500 megawatts of power. For comparison, the largest solar facility in the United States, the Copper Mountain Solar Facility in Nevada, takes up 4,000 acres of land and yet generates slightly more power (802 megawatts).

In theory, if a controlled nuclear fusion process could produce more energy than was put into it, the technology could be used to create an almost unlimited supply of safe, clean energy. The problem is in the engineering: creating such collisions requires heating plasma to millions of degrees, hotter than any vessel that might contain them could withstand. The workaround, historically, has been to energize powerful magnets that keep fusion-ready gases floating in a confined vacuum, sometimes while being bombarded with lasers that superheat them.

While humans have created controlled fusion reactions for short periods of time, getting out more energy than which is put into the reaction has proved exceedingly difficult.

Now, according to an unconfirmed report first broken by the Financial Times, the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory in California may have achieved a "net energy gain." If this finding is true and can be repeated, it could pave the way for using nuclear fusion to provide unlimited energy to the planet.

To be clear, the ignition (a term used for producing more energy than utilized in these contexts) was only 50 percent, which the Financial Times concedes is "far below what would be needed for a commercial reactor." At roughly 0.4 MJ (megajoules), the ignition produced just enough energy to boil a tea kettle, which is hardly sufficient to base a viable commercial model. The hope, however, is that the recent breakthrough will inspire additional innovations that could one day take humanity to a future of almost-bottomless energy.

"Fusion has the potential to provide a near-limitless, safe, clean, source of carbon-free baseload energy," explained Dr. Robbie Scott of the Science and Technology Facilities Council's (STFC) Central Laser Facility (CLF) Plasma Physics Group in a statement to The Guardian. "This seminal result from the National Ignition Facility is the first laboratory demonstration of fusion 'energy-gain' – where more fusion energy is output than input by the laser beams. The scale of the breakthrough for laser fusion research cannot be overstated."

Scott added, "The experiment demonstrates unambiguously that the physics of Laser Fusion works. In order to transform NIF's result into power production a lot of work remains, but this is a key step along the path."

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Another challenge in developing effective nuclear fusion-based energy sources is that scientists are not even sure which methods would be best. The NIF used a process known as inertial confinement, which creates an implosion — in their case, by focusing 192 laser beams on a fuel capsule containing hydrogen isotopes that is roughly the size of a peppercorn. However, most fusion labs instead use an approach known as "magnetic confinement," one that entails holding those hydrogen isotope-fueled in a doughnut-shaped reactor by using powerful magnets.

"For either approach to lead to a cost-effective power station, almost every aspect of today's experimental reactors needs transforming," the Financial Times observed.

Nevertheless, experts and public officials are still hailing the latest development as good news.

""his is such a wonderful example of a possibility realized, a scientific milestone achieved, and a road ahead to the possibilities for clean energy," White House science adviser Arati Prabhakar, said during a news conference on Tuesday morning. "And even deeper understanding of the scientific principles that are applied here."

This isn't the first promising fusion news to emerge from NIF in recent history. Last year, the same reactor was able to produce 1.3 megajoules of energy through an experiment that focused the laser light onto a BB-sized target — generating more than 10 quadrillion watts of fusion power over a span of tiny fractions of a second.

"Gaining experimental access to thermonuclear burn in the laboratory is the culmination of decades of scientific and technological work stretching across nearly 50 years," Thomas Mason, who directs the Los Alamos National Laboratory which helped with the project, said in a press statement at the time. "This enables experiments that will check theory and simulation in the high energy density regime more rigorously than ever possible before and will enable fundamental achievements in applied science and engineering."