The US' laser-powered Department of Energy's National Ignition Facility (NIF) has more than doubled its net-positive fusion energy output from 3.15 megajoules in 2022 to 8.6 megajoules. The experiment in 2022 was the first controlled fusion reaction to generate more energy than it consumed. The NIF uses what is known as 'inertial confinement' to produce fusion reactions.