What's the state of nuclear fusion after the National Ignition Facility breakthrough?
In December 2022 a laser lab got out more fusion energy than its laser put in, but less than 1% of the energy it used overall.
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Fusion is not yet making electricity for anyone, but one lab has shown it can release more energy than the laser put in. In fusion, two light atomic nuclei combine into a heavier one and release energy, the opposite of the splitting that powers today's reactors. On 5 December 2022 the National Ignition Facility in California reached what is called scientific for the first time, producing 154 percent of the energy of its laser.
That headline needs context. The laser pulse delivered 2.05 and the experiment yielded 3.15, but the pulse took about 300 megajoules to produce, so the experiment produced less than 1 percent of the energy used to create it. As of 2025, NIF is the only laboratory to have shown a gain above one, and far higher efficiencies are needed for a plant that makes net electricity. Later shots reached more than 5 megajoules in February 2024 and 8.6 in 2025.
NIF's December 2022 shot, in megajoules
| Energy | |
|---|---|
| Laser pulse on target | 2.05 MJ |
| Fusion energy out | 3.15 MJ |
| Energy to make the pulse | 300 MJ |
The big international project is ITER in France, designed to demonstrate fusion's feasibility, though not to generate electricity. It once planned first in 2020; in July 2024 it announced a new schedule with - operations in 2039. Meanwhile private companies have raised large sums, and some have announced plans, which are claims rather than results.
Supporters point to minimal high-level waste and lower inherent safety risk. Challenges include neutron damage to reactor walls and scarce . An old joke says fusion is always 30 years away.
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Recap
Fusion has passed scientific breakeven in a laser lab, but net electricity from a machine is still to be shown.
💡 A trick to remember it · Fusion joined the first rung of the ladder in 2022, and the rest of the ladder is still standing.
Surprising fact · NIF's 2022 shot returned 154% of the laser energy but less than 1% of the energy used to make the laser pulse.
Connects to
- 📦 Are small modular reactors a breakthrough or still a promise?
- ⚛️ How does a nuclear power plant turn splitting atoms into electricity?
- 🧂 What are thorium and molten-salt reactors, and do they live up to the hype?
- ⚛️ What does E = mc² actually say?
- 🧊 Why does electrical resistance vanish completely in a superconductor?
- 🛰️ Why would anyone put solar panels in space instead of on Earth?
- Enriched uranium
- Energy security
Sources (3)
No source, no claim. Every fact in this lesson (15 claims) cites at least one of these.