News

Scientists hit a key milestone in the quest to create abundant zero-carbon power through nuclear fusion. But they still have a long way to go.

The Department of Energy plans to announce Tuesday that scientists have been able for the first time to produce a fusion reaction that creates a net energy gain — a major milestone in the decades-long, multibillion-dollar quest to develop a technology that provides unlimited, cheap, clean power.

In some ways, scientists at the Department of Energy’s National Ignition Facility (NIF) have been a bit down and out. The $3.5 billion facility was designed to replicate the atom-smashing reactions that occur inside the sun, a difficult process that requires enormous amounts of heat and pressure, and could theoretically solve humanity’s energy and climate woes.

But technical obstacles put NIF a decade behind in its goal of achieving fusion “ignition,” that is, getting more energy out of one of those reactions than it put in. The facility uses the largest lasers in the world to try and do that, focusing energy on a tiny capsule filled with hydrogen isotopes.

U.S. scientists have achieved “ignition” — a fusion reaction that produced more energy than it took to create — a critical milestone for nuclear fusion and a step forward in the pursuit of a nearly limitless source of clean energy, Energy Department officials said Tuesday.

Nuclear fusion, the process that powers the sun and other stars, occurs when two atoms’ nuclei collide under extreme temperatures, causing a reaction that can generate incredible amounts of energy with few environmental costs.

The latest step toward pollution-free power has the potential to transform the energy sector, perhaps decades from now, but some companies are already positioning themselves to benefit.

Energy Secretary Jennifer Granholm said on Tuesday that scientists at the Lawrence Livermore National Laboratory in California had made “a tremendous scientific breakthrough” in their tests of nuclear fusion, the reaction that powers the sun. While prior efforts to achieve fusion—combining two hydrogen atoms to produce helium in a reaction that produces energy—consumed more energy than they released, the Livermore scientists flipped the balance.

The promise of zero-carbon energy has long been too good to be true, but researchers say they’ve found a breakthrough in what’s known as fusion energy. Fusion energy is a process that occurs in our Sun and other stars and doesn’t emit greenhouse gasses or radioactive waste.