The fusion startup Helion, backed by Sam Altman, has raised another 465 million dollars at an estimated valuation of 15.5 billion. The money comes as the company races to finish Orion, its first plant, with the promise of delivering fusion power to the grid as early as 2028 - under its deal with Microsoft. With this round, total funding has reached 1.5 billion dollars.

Helion takes a different path from the competition. While some use magnets and others lasers, Helion uses magnets to squeeze the fuel mixture and plans to draw electricity directly from the magnetic fields. When fusion happens, the expanding plasma pushes against the magnetic fields, and that force is tapped as electricity - a principle similar to regenerative braking in electric vehicles. On paper, that could dramatically improve efficiency. On paper.

Because that's exactly where the scepticism sits. Some fusion experts aren't convinced the thing will work as promised. CEO David Kirtley answers briefly and confidently: „We don't want to theorise about fusion. We just want to build it.” Confidence is cheap until the plant produces its first watt for the grid.

Helion isn't alone in this race. Focused Energy recently raised 240 million, Thea Energy 100 million, Inertia Energy emerged from stealth with a 450-million round, and Type One Energy is chasing 250 million. Why are investors piling money into a technology that won't deliver a commercial plant before the mid-2030s? Because AI companies are starving for electricity that runs around the clock, and fusion promises abundance from seawater. The promise is enormous - so are the deadlines.