Fusion powers ahead

 By Amanda Saint

In December 2015, the Max Planck Institute for Plasma Physics in Germany turned on the Wendelstein 7-X nuclear fusion reactor — the largest stellerator fusion reactor ever built. Researchers are now moving into advanced testing stages and hope to prove that nuclear fusion can be developed into a safe, reliable and commercially viable source. The findings may help dramatically cut carbon emissions while ensuring power supplies remain in place as the global population grows…

(Cover Photo by

Led by Professor Thomas Klinger, the team at the Max Planck Institute has been working to design and develop the W7-X stellarator for 15 years. Now that the reactor has been switched on (and if it delivers on expectations), nuclear fusion may emerge as a new primary energy source, with potential to significantly contribute to the global energy supply.

Previously, the promise of nuclear fusion was hampered by the difficulty in keeping the machines in continual operation. This is due to the fact that in order for it to work, super-hot plasma needs to be contained inside. Klinger said: “The W7-X stellerator is so magnetically efficient that it’s the first nuclear fusion reactor that can contain the plasma for more than 30 minutes at a time.”

The first plasma creation tests have been very short, just a tenth of a second, but have achieved a temperature of around one million degrees celsius. The timings will now be gradually increased throughout the testing stage.

(Wendelstein 7-X Nuclear Fusion Reactor, imagine by


A Viable Energy Option?

Understandably, Klinger and his team are excited about the potential, but the World Nuclear Association (WNA) is taking a more cautious approach. Dr Jonathan Cobb, Senior Communications Manager at WNA said: “It’s a promising step, but this is still an experimental reactor. In terms of contributing to future mainstream energy generation, we are probably looking at the second half of the century before any fusion technology, should it be possible to develop such technology to commercial deployment, starts generating electricity in substantial quantities that could contribute to clean energy generation.”

The W7-X has taken a year to build and the project has cost many millions of dollars so far. The components needed to make it work are heavy and the construction of the stellarator is tricky, but despite these obvious drawbacks the first signs from the testing phases show promise.

Cobb said: “There will be a need for new low carbon capacity to be built in significant quantities post-2050, so nuclear fusion could play an important part of meeting our long-term emissions goals. But there is also a need to reduce emissions much sooner, with the majority of electricity generation coming from low carbon sources by 2050, if we are to achieve the temperature stabilization goals recently set at COP21. So, nuclear fission, rather than fusion, will have a very important role to play in helping to achieve this goal and contributing, potentially alongside fusion, beyond 2050 as well.”

Nuclear fusion by

Fission or Fusion?

Nuclear fission, which is the nuclear power we’re already using, provides affordable, predictable and reliable low carbon electricity for many countries worldwide. Cobb added: “Statistics from organizations such as the International Energy Agency project that nuclear fission could supply more than 17% of global electricity by 2050, more than any other individual generation technology.” To achieve this percentage we will require nearly 1000 GWe of nuclear capacity. Figures from the Nuclear Energy Institute show that in 2015 global capacity was just over 379GW.

Klinger was quick to point out that the W7-X is just a step towards the ultimate goal of nuclear fusion being a primary energy source. He said: “One of our goals is to maintain fusion relevant plasma parameters for about thirty minutes and thus to prove that an optimized stellarator can be operated under high-power steady-state conditions.”

“This is an ambitious program that intends to position the optimized stellarator as a candidate for a future fusion power plant. However, W7-X cannot address all scientific and technical questions alone,” he continued.

As the scientific community works to answer these questions, there is another issue that is always at the forefront of people’s minds when it comes to nuclear — safety.

Cobb said of this: “It is important to distinguish safety concerns from the actual safety of any generation technology. Whether the safety of fusion reactors is perceived any differently to that of fission reactors today remains to be seen. Current nuclear technology is among the safest of any generation technology, fossil or renewable, so new fusion technology will have a very high level of safety if it can match or exceed current nuclear generation.”

With its impressive safety and environmental credentials, it seems that nuclear is going to be an increasingly important source of energy in the years to come. Whether the W7-X will help to make nuclear fusion a viable option remains to be seen.

about the author
Amanda Saint
Journalist and content writer, specialised in engineering and technology with a focus on environmental sustainability, urbanisation and biotechnology.