What is nuclear fusion?

Originally conceived in the 1920¡¯s, the idea of nuclear power was taken straight from the stars. Scientists wondered how the sun could self-sustain large amounts of energy for millions of years. Ultimately, they discovered that the sun and other stars are powered by nuclear fusion.

Generally, the process of fusion involves combining two small atoms¡ªlikely two hydrogen isotopes¡ªto create one large atom, helium. The kicker? The process of fusion also creates bountiful energy as a result. This energy can be used to generate electricity, sustainably.

Fusion is not to be confused with nuclear fission, which splits large atoms (likely of uranium or plutonium) while releasing energy in the process. Right now, the nuclear power plants in operation use fission to produce electricity. Fission produces heat that is used to boil water, creating steam that spins a generator and produces electricity. But the process also produces radioactive waste as a biproduct, which has to be stored or reprocessed (and in rare circumstances can lead to an uncontrolled reaction). This has led some to oppose its use.

That¡¯s why there is surging interest in fusion: It has more energy potential than fission but does not have the potential for an uncontrolled nuclear reaction or the issue of long-lived radioactive waste. The process can be shut down immediately in the event of a failure by removing the input of fuel¡ªunlike the disaster at Chernobyl that burned for more than a week.

If the energy industry hopes to replace fossil fuels with fusion, the practical first step is to help the world understand how it¡¯s more sustainable¡ªand safer¡ªthan fission.

What¡¯s holding us back from fusion?

As any energy expert will tell you, fusion technology has always been 30 years away from practical application. And every time it seems like progress has been made, other issues pop up and extend the timeline. So, what are the barriers to sustainable fusion?

As outlined above, the primary barrier to fusion energy is perception. People have often felt skeptical about fusion¡ªsome may find it a risky proposition (associating it with the problems of nuclear fission) while others may believe the technology is impossible to achieve. Either way, when there is this lack of buy-in from the public it generally leads to slower research and development and a lack of resources to hit its full potential.

Another barrier to fusion is creating a completely controlled environment that can contain the process. This is called a nuclear fusion reactor and it¡¯s absolutely essential for sustainable fusion. Look no further than the creation of the hydrogen bomb, which unleashed the power of fusion in an uncontrolled environment.

Generating fusion in a controlled environment is a tall order. Why? Because the process requires an environment that can withstand temperatures over 100 million degrees Celsius¡ªthat¡¯s more than 180 million degrees Fahrenheit! A fusion reactor also requires a series of high-temperature superconducting magnets. These create an energy field of electrostatic force so that the fusion reaction can be safely contained. Recent breakthroughs in this area may lead to much more rapid advancement of the practical application of this technology. (1)?

And then there are the barriers of time and talent. Will fusion energy be possible within the next 30 years, in time for our 2050 net zero goals? And will we have enough experts working on fusion to make that possible? These are questions that still need answering.

Is there a working fusion prototype today?

The short answer here is: Sort of. While there have been successful fusion reactions, current technology has had its limitations. How so? Well, so far fusion reactors haven¡¯t been able to produce more energy than is needed for the process. Experts call this Q=1, or in some instances, Q<1 when more energy is needed to create the reaction than comes out of it. This must change if we hope to practically apply fusion technology on a large scale. But it is possible.

In fact, there is an ongoing effort at the Massachusetts Institute of Technology (MIT) by Commonwealth Fusion Systems (CFS) that has been steadily working towards their 2025 goal of creating a working fusion prototype. And inspiringly, they have been hitting their scheduled goals for the past several years!

In September 2020, CFS published seven peer-reviewed papers in the Journal of Plasma Physics that detail their approach. Unlike in past times when a research group would mysteriously allege that they could accomplish a Q>1 fusion system, CFS outlines how their plan will actually work.

By using the world¡¯s strongest high-temperature superconducting magnets, CFS believes their fusion reactor can not only work, but function at a rate of Q=10. This is an incredible breakthrough! Essentially, it means that if CFS inputs 10 megawatts (MW) of energy into their reactor, they can generate 100 MW of energy. The best part? Most of the independent physicists and engineers who study fusion believe that CFS¡¯ plans may actually work.

Now wielding the most powerful magnetic field ever created on Earth, CFS is on schedule to complete a working protype by 2025. If they are successful, they hope to build a commercial facility by 2030. Mass deployment of these facilities would be incredibly complex and take decades to achieve, but it could be possible by 2050 if we give the industry the resources and financing it needs to succeed. For the first time, we are starting to see private investment in fusion technology on the billion-dollar scale. This is a sure sign that there are real possibilities for practical application. (2)

The path to a fusion future

Nuclear fusion is an ambitious goal. But we must be bold and take strong, deliberate action if we hope to reach net zero by 2050. Nuclear fusion could eventually be the primary pillar of our energy infrastructure, and it would transform the world in a historic way.

The demand for electricity is expected to increase exponentially as we electrify our vehicles, buildings, and other technologies. So, clean and affordable electricity generation is a critical factor in meeting our global sustainability and climate action goals.?

Fusion energy is not only a clean and self-sustaining form of energy, but it could also be the cheapest energy since chopped wood. Yes, an incredible amount of capital will be needed for research and innovation. But once we have a working facility ready for mass deployment, energy prices could be significantly reduced.

The energy transition will be a massive, multi-decade undertaking. And our understanding of the combination of energy resources and innovations that will allow us to succeed is still emerging. A lot of sustainable energy, like solar and wind, is more distributed and requires different electricity system infrastructure. Nuclear fusion would follow a more centralized model like current fossil fuel and nuclear generation plants. Our teams have the skills to develop both of these energy system models, and we are always adapting and learning about new technological innovations when they become available.?

How would the economy change if everyone¡¯s power bill was significantly reduced? What if we applied those power costs to every other industry like manufacturing and agriculture? How would engineering designs change? What about home designs?

Fusion is an untapped resource with almost limitless potential. A big idea? Sure. But we need to be thinking big these days if we hope to successfully develop sustainable, clean, and cheap energy.

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