01
Heat
The sun is 15 million °C and has gravity. We need ~100 million °C because our machines are tiny and impatient.
A public atlas · 2026
Fusion is the sun’s engine. On Earth it is a confinement problem: heat hydrogen hotter than the core of a star, hold it without touching a wall, and make more energy than you spend. Hover a machine. Click to go inside.
The primer
Every commercial path fuses light nuclei. The fight is how you confine the plasma long enough for Q — energy out over energy in — to go above one. America is funding more than one bottle on purpose.
The sun is 15 million °C and has gravity. We need ~100 million °C because our machines are tiny and impatient.
Magnets, inertia, or a self-made pinch. If the plasma hits a wall, it dies. That is a safety feature.
Q>1 is net fusion energy. A power plant still has to turn that heat — or a changing magnetic field — into electrons on a wire.
The bottles
Live 3D. Hover to spin faster. Each card is a real architecture U.S. companies are building — not a museum piece.
A magnetic bottle shaped like a doughnut. The most studied fusion machine on Earth. SPARC is the U.S. commercial bet.
A twisted torus. The magnets do the steering so the plasma does not need a huge current. Built for steady operation.
Two compact plasmoids smash together. Helion and TAE turned this into America’s other billion-dollar path.
Run a huge current through the plasma. It makes its own magnetic field and squeezes itself. No giant magnets. No lasers.
Crush a fuel pellet with lasers or pulsed power before it can fly apart. NIF proved ignition. Startups are trying to make it a plant.
A cigar of plasma between two magnetic corks. Simple geometry. HTS magnets brought it back as an industrial-heat machine.