We made a star in a lab — we still can't plug one into the grid

The problem

In December 2022 the National Ignition Facility achieved fusion ignition, releasing 3.15 megajoules from a fuel capsule hit with 2.05 megajoules of laser light — the first time a lab fusion reaction produced more energy than was delivered to the target. NIF has since repeated ignition many times, reaching a record 8.6 MJ from 2.08 MJ of laser energy in April 2025. But that gain counts only the laser light on target: the facility draws vastly more electricity from the grid per shot, and fires a few times a day, not several times per second as a power plant would need. Engineering net energy — a machine whose total electrical output exceeds its total input, with walls, magnets, and fuel cycles that survive years of operation — remains unsolved. ITER's re-baselined schedule pushes full deuterium–tritium operation to 2039, while private machines like Commonwealth Fusion's SPARC race to demonstrate net fusion gain in a compact device.

Why it matters

Practical fusion would mean carbon-free power from fuel extracted from seawater and lithium, with no long-lived high-level waste and no meltdown risk. Whether it arrives in the 2030s or never is one of the largest open questions in energy — and billions in public and private capital hinge on the answer.

Progress so far

• 1951Lyman Spitzer proposes the stellarator; dedicated controlled-fusion programs begin
• 2022NIF achieves fusion ignition: 3.15 MJ out from 2.05 MJ of laser energy delivered to the target
• 2024ITER adopts a new baseline: research operations from 2034, full deuterium–tritium operation delayed to 2039
• 2025NIF sets a new record: 8.6 MJ yield from 2.08 MJ of laser energy, a target gain above 4
• 2026Commonwealth Fusion Systems' SPARC tokamak assembly advances, first plasma targeted for 2027

References

1. Lawrence Livermore National Laboratory (NIF) — official account of the 2022 ignition milestone and what target gain does and does not mean
2. Lawrence Livermore National Laboratory (NIF) — the April 2025 record shot: 8.6 MJ from 2.08 MJ, target gain greater than 4
3. ITER Organization — the 2024 updated baseline schedule for the world's largest tokamak
4. Commonwealth Fusion Systems — SPARC, the compact high-field tokamak designed to demonstrate net fusion energy gain