Wendelstein 7-X
Wendelstein 7-X is a stellarator fusion device run by Max Planck Institute for Plasma Physics in Germany. It is operating. Like every fusion device built so far, it has produced no net electricity.
The largest stellarator ever built, setting successive records for plasma duration and the triple product that measures fusion performance.
A stellarator twists its magnetic field with the shape of the coils rather than by driving a current through the plasma. That makes the magnets fiendish to build. W7-X's coils were only practical once modern computational optimisation existed, but it removes the current-driven disruptions that are a tokamak's central problem, and it can in principle run continuously.
| Organisation | Max Planck Institute for Plasma Physics |
|---|---|
| Approach | stellarator |
| Confinement | magnetic |
| Country | Germany |
| Status | Operating |
| First plasma | 2015 |
| Target date | none stated |
|---|---|
| Power target | none stated |
| Energy gain target | none stated |
| Net electricity | No. no fusion device has produced any |
Other stellarator projects
| Project | Status |
|---|---|
| Infinity Two | Planned |
| Large Helical Device |
Fusion needs tritium, and the world's civilian stock comes mostly from CANDU fission reactors. See the fusion overview.
Wendelstein 7-X in context
3 of the 24 fusion projects on record use the stellarator approach: 2 operating, 0 under construction, 1 planned.
Its first plasma is dated 2015, 11 years ago: the 8th earliest of 15 projects on record with a first-plasma date.
| Measure | Wendelstein 7-X | Median of all projects | Standing |
|---|---|---|---|
| First plasma | 2015 | 2015 | 8 of 15 (earliest first) |
Worked out from the entries on this site only, so a figure compares Wendelstein 7-X with what is recorded here, not with everything that exists. An entry with no value for a measure is left out of that measure's ranking and median.
Sources
- World Nuclear Association, Nuclear Fusion Power · retrieved 2026-09-07
How these sources are used, including the corrections applied on top of them and what is deliberately left blank · download the underlying data