Editor’s note: Marshall Brain – futurist, inventor, NCSU professor, writer and creator of “How Stuff Works” –  takes his weekly Doomsday column on an energy tack this week. Marshall is a contributor to WRAL TechWire.  Brain takes a serious as well as entertaining look at a world of possibilities for Earth and the human race.  He’s also author of “The Doomsday Book: The Science Behind Humanity’s Greatest Threats.” Brain has written several posts recently about the threat of climate change. His exclusive columns written for TechWire are published on Fridays. 

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RESEARCH TRIANGLE PARK – If we can figure it out, fusion could be the ultimate power source for humanity. It sounds so simple:

  1. Take some hydrogen atoms
  2. Compress them close together so they fuse with each other
  3. Extract a bunch of heat energy from that fusion process

The reason why fusion power would be such a breakthrough for humanity is because hydrogen is abundant, fusion power would not be intermittent like solar and wind, and fusion does not pollute the environment. Fusion does not produce carbon dioxide like coal and does not have the large “nuclear waste” problem that our existing nuclear power plants have.

The hurdle with fusion has always been the technical difficulty of creating a large-scale, working fusion reactor. Therefore, fusion has seemed like one of those technologies that is always 30 years away.

But this year things are starting to change on the fusion front. There has been a big announcement this week:

Microsoft is aligning with the company Helion. The company has raised $2+ billion to bring fusion to the marketplace with its new fusion technology. Given past history, a five-year timeline for fusion power sounds almost absurd. But Helion representatives sound confident. Why has fusion been so difficult?

The problem with Fusion

On the one hand, fusion is simple and common. Our sun is a giant fusion reactor, and every star we see in the sky is a fusion reactor as well. Given that there are approximately 200 billion stars in our galaxy alone, it is easy to see how common fusion is. A star becomes a fusion reactor in three steps.

  1. A star collects a gigantic amount of hydrogen gas in one place. Think about how big planet Earth is. Multiply by 1.3 million. This is how big our sun is. The sun weighs 300,000 times more than planet Earth does.
  2. All that hydrogen creates an immense gravitational field, far stronger than the gravity we feel on Earth.
  3. At the center of the sun, all that gravitational pressure forces hydrogen atoms to fuse together. All of the energy that gets created by these fusion reactions turns the sun into a giant furnace of heat and light.

Fusion is easy and natural inside a star.

The problem with creating a fusion reactor on Earth comes in two parts. First, we must create enough pressure to fuse atoms together. And second, we have to create a container that maintains its integrity despite the pressure and the heat produced by the fusion reactions. In the sun, the pressure is a natural byproduct of gravity, and then there is no need for a “container” – gravity holds everything together.

Scientists have been working on the tokamak system to create a fusion reactor for many decades. The best example of the idea today is called ITER in Europe. Here is a great explanation of ITER: https://www.youtube.com/watch?v=4BkOUOK0XzM

ITER is costing $20+ billion and maybe it produces power in 20 or 30 years? And then the question will be, “how do we replicate ITER? How do we scale to thousands of ITER reactors?”

China has also been doing tokamak fusion research called CFETR, as described here: https://www.youtube.com/watch?v=z3ontLP4lGI

Helion and other fusion startups are thinking differently

What is happening at Helion and other fusion startup companies is different. They propose fusion reactors that are:

  • Much smaller scale
  • Much less expensive
  • Quicker time to market
  • Not using tokamak technology

Helion describes its technology – which they call Trenta – in this video: https://www.youtube.com/watch?v=_bDXXWQxK38


The video summarizes Helion’s technology this way:

“A completely novel approach to nuclear fusion… The generator forms two mirrored rings of plasma at either end of the reactor. In a tenth of a thousandth of a second they fire them at each other. Sequentially activating powerful magnets to squeeze and compress the rings toward the center where they collide converting the astonishing kinetic energy of the ions traveling at 300 km/sec to thermal energy, raising the plasma temperature to tens of millions of degrees, hot enough to overcome the electromagnetic repulsion keeping them apart and allowing them to fuse, forming new atoms and releasing a tremendous amount of energy in the process. This is not the world of fairy tales. This is already happening.”

Meanwhile there is another company called General Fusion (https://generalfusion.com/) that uses a completely different approach to compress the hydrogen: https://www.youtube.com/watch?v=rdOfW6h77ZU

Meanwhile there is another company called NearStar Fusion (https://www.nearstarfusion.com/) with its HGFF fusion technology to compress capsules of hydrogen fuel one after another: https://www.youtube.com/watch?v=55fwPgVApDo

There is another company called TAE Technologies (https://tae.com/)  with its C-2W technology using boron rather than hydrogen: https://www.youtube.com/watch?v=EVlWUQ-UKa4

Meanwhile another company called Commonwealth Fusion Systems (https://cfs.energy/) has a system called SPARC: https://www.youtube.com/watch?v=-KEwkWjADEA

All of these technologies are fascinating, all completely different, and are all trying to achieve scalable fusion in just a few years:

  1. Helion
  2. General Fusion
  3. NearStar Fusion
  4. TAE Technologies
  5. Commonwealth Fusion Systems

Will any of these manage to succeed in their goals in this decade? If so, will a new fusion reactor technology change our world for the better? Over the next few years, we should be able to find out.