Sam Altman’s fusion startup Helion Energy hits 150 million degree plasma temperature—a milestone that could bring first grid power in 2028

The Sam Altman-chaired Helion Energy fusion power developer announced a new milestone Feb. 13 achieving record plasma temperatures at 150 million degrees Celsius—10 times the core of the sun—as part of its immensely ambitious goal to bring power to the grid in Washington state in 2028.

Startup developers of fusion energy—the so-called power of the stars in a jar—are racing to prove their technologies and bring clean, limitless electricity to the grid to meet the power needs of the AI boom.