The U.S. energy system is in the middle of an all-out revolution. Growing electricity demand has contributed to a massive build out of any power source that utilities can get their hands on—often gas and solar power, typically the two cheapest options these days. Meanwhile, the country has cemented its place as a superpower in fossil fuel production. Fusion energy, which has for decades been considered as distant and almost like science fiction, has the potential to reshape all of these trends.