German Fusion Reactor Reaches 40 Million Degrees

Germany’s Max Planck Institute for Plasma Physics just took a big step towards building the world’s most powerful fusion reactor.

The Wendelstein 7-X stellarator heated plasma to 40 million degrees Kelvin, Science Alert reported. That’s apparently the highest temperature ever set in a laboratory on Earth. That was four times hotter than the last operating temperatures.

Such temperatures would be necessary to generate a sustained fusion reaction stable enough to serve as a power source. The stellarator achieved those temperatures by using 18 times more energy than used in earlier tests. That indicates a stable and sustainable fusion reaction is possible.

Far more power and heat will be needed to achieve fusion around 100 million degrees Kelvin. That means the stellarator might be 40% of the way to a hot fusion reaction.

Stellarator on the Road to Fusion

The stellarator in Greifswald, Mecklenburg-Vorpommern, uses a radically different design than tokamak reactors like MIT’s Alcator C-Mod and the hideously expensive International Thermonuclear Experimental Reactor (ITER) in Cadarache, France. Tokamaks use electromagnetic fields to contain the super-hot plasma while a stellarator utilizes magnetic coils to contain the plasma.

The stellerator’s design offers more control and safety, because machines are in control of the process. Stellarators have a very funny shape; they look like a steampunk version of the Millennium Falcon, in order to keep super-hot hydrogen jelly swirling around in a giant loop.

This keeps the plasma a little more stable but it has a long way to go achieve anything contract. Currently the Wendelstein 7-X stellarator can generate reactions for six to 25 seconds. That’s far from what is needed for commercial power generation but it is a start.

Stellarator Lags behind MIT

Despite that power production with a stellarator is probably years away. There’s not even a schedule for commercialization yet. This puts the stellerator behind its most visible American competitor.

Researchers at MIT’s Plasma Science and Fusion Center (PSFC) are so confident in the Alcator C-Mod; that they have set up a company called Commonwealth Fusion Systems to commercialize their technology. Commonwealth has received a $50 million investment from the Italian oil company Eni S.P.A. (NYSE: E). Eni’s head of development and technology Robert Casula thinks a fusion reactor capable of generating 200 million watts; or 200 megawatts of electricity, might be built by 2033.

The Commonwealth Fusion Systems team has plans for a 100 megawatt (100 million watt) demonstration reactor called the SPARC that might be up and running within a decade. Unfortunately, Commonwealth Fusion has no presented any evidence for its claims.


Still it will probably be a matter of time before somebody tries to commercialize the Stellerator technology.

Would Hot Fusion be a Good Energy Source?

A vast amount of work will have to be done before hot fusion might become a viable energy source. An obvious question is how will the super-hot plasma be contained without setting everything around it on fire?

The Wendelstein 7-X utilizes special tiles and support structures developed by the Max Planck Institute for Plasma Physics to contain the heat Phys.Org reported. These have to be specially designed and custom-built to specifications so they are expensive.

A more important question is how to convert all that heat into power. An obvious solution is to generate steam to run turbines. Another fascinating possibility is to use photovoltaic cells like those in solar panels to convert the light created into electricity.

More difficulties include the use of exotic elements including a super rare variety of hydrogen called tritium. Tritium has to be created in another reactor which is super expensive.

Fusion is a Technology to Watch

Fusion is still years away but it is a technology to watch because of its potential. Theoretically fusion can generate unlimited amounts of energy at a low cost without generating pollution.

We have already seen the havoc wreaked by cheap oil and cheap natural gas. Some experts think super-cheap photovoltaic solar panels will be even more disruptive because they can make vast amounts of electricity almost anywhere.

Fusion’s potential to disrupt markets is greater. One of its effects might be to make it possible to give electricity away for free or at very low prices. Another would be to make to close to unlimited amounts of computing power available which would be incredibly disruptive. Other uses would be to greatly reduce the cost of industrial processes such as plastics manufacturing and oil refining.

Understanding fusion’s potential might be critical for investors.