[Udo]

Releasing more energy than what's put in to run the facility is a necessary property of all power plants. It costs energy to mine and process fossil and fission fuels, it costs energy to produce and maintain solar farms. None of this breaks thermodynamics, because none of this is reversing the flow of entropy. Energy is released, it's not created out of nothing.

In this specific case, hydrogen atoms are fused together, which is a reaction that releases energy because the resulting combined atomic nucleus is at a lower energy state than the atoms that went in. This technically holds true for fusion up until you get iron nuclei, with heavier atoms than iron requiring energy to be put into the reaction when fusing. This is the other side of the equation, which we are already using for nuclear fission plants.

Bashing nuclei together hard enough to overcome their innate repulsion is where most of the input energy is going in fusion reactors. It is comparable to the concept of activation energy in chemical reactions.

Keep in mind that this announcement does not cover the total energy cost of running the reactor, "only" the theoretical amount of energy released into the chamber by the ignition laser. So we're a long, long way off from achieving what they call "unity" (an input/output ratio of 1:1) in practical terms. In theory, fusion reactions achieving practical unity can be self-sustaining. Although this specific way of triggering a fusion reaction is not continuous, it could theoretically be re-worked into a permanently running reactor that is pulse-driven in the same way an internal combustion engine is.