Microsoft just made a big, far from safe bet on nuclear fusion

Microsoft has just signed a striking deal to buy electricity from a nuclear fusion generator. Nuclear fusion, often called the holy grail of energy, is a potentially limitless source of clean energy that scientists have been chasing for more than a century.

A company called Helion Energy believes it can deliver the holy grail to Microsoft by 2028. It announced a power purchase agreement with Microsoft this morning that would see it connect the world’s first commercial fusion generator to a power grid in Washington. The goal is to generate at least 50 megawatts of power – a small but significant amount and more than the 42 MW that America’s first two offshore wind farms have the capacity to generate today.

To say it’s a tall order would be the understatement of the year. “I’d say that’s the boldest thing I’ve ever heard,” says theoretical physicist Robert Rosner of the University of Chicago. “In such matters, I will never say never. But it would be amazing if they succeed.”

Experts’ optimistic estimates for when the world could see its first nuclear fusion power plant have ranged from the end of the decade to several decades from now. Helion’s success depends on achieving remarkable breakthroughs in an incredibly short time and then commercializing the technology to make it cost-competitive with other energy sources. Still, Helion is unmoved.

“This is a binding agreement that has financial penalties if we can’t build a fusion system,” says Helion founder and CEO David Kirtley The Verge. “We have committed to being able to build a system and sell it commercially [Microsoft].”

How might a fusion system work? Simply put, nuclear fusion mimics the way stars create their own light and heat. In our Sun, hydrogen nuclei fuse together, creating helium and generating an enormous amount of energy.

Scientists have been trying to recreate this process in a controlled way since the 1950s. (They have been able to recreate it in one uncontrolled way, also known as a hydrogen bomb.) This is the opposite of the nuclear power plants we have today which release energy through fission, or the splitting of atoms. A major disadvantage of fission is that it leaves unstable nuclei that can remain radioactive for millions of years. Fusion avoids the problem of radioactive waste because it essentially just creates new helium atoms.

The most advanced attempts to generate electricity through nuclear fusion involve firing powerful laser beams at a small target or relying on magnetic fields to confine superheated matter called plasma with a machine called a tokamak.

Helion uses none of these methods. The company is developing a 40-foot device called a plasma accelerator that heats fuel to 100 million degrees Celsius. It heats deuterium (an isotope of hydrogen) and helium-3 into a plasma and then uses pulsating magnetic fields to compress the plasma until fusion occurs. (The company has a Youtube video that illustrates the process in much more detail.)

Helion claims that the machine will eventually be able to recapture the electricity used to trigger the reaction, which can be used to charge the device’s magnets. “We electrically recover all the energy we put into fusion, so we can actually build systems that are smaller and cheaper, and we can iterate on them much faster,” says Kirtley.

“This is an exciting announcement and many in the community will be interested to see the technical details,” MIT School of Engineering Distinguished Professor Anne White said in an email to The Verge. “Forthcoming publications and results will help clarify the approach and understand the timeline.”

Figuring out how to be energy efficient is crucial to making fusion power a reality. After all, you need extreme heat and pressure to force atoms to fuse together. And until recently, scientists had been unable to do this without burning through more energy than the fusion reaction actually produced. In December, lasers achieved a major breakthrough called “fusion ignition” – meaning that for the first time scientists could trigger a fusion reaction that resulted in a net energy gain. It is an important milestone Helion has yet to achieve.

Getting enough helium-3 fuel could be another big challenge, Rosner says, without a way to produce commercial quantities of it. It is a very rare isotope used in quantum computing and medical imaging. However, Helion says it has patented a process to make helium-3 itself by fusing deuterium atoms together in the plasma accelerator. Part of the appeal of nuclear fusion in the first place is that it can run on hydrogen, the simplest and most abundant element in the universe.

Assuming Helion can pull off all of this, it still needs to make sure it can do so affordably. The cost of the electricity it generates for consumers must be comparable to or cheaper than today’s power plants, solar energy and wind farms. The company is not sharing the price they agreed to in the power purchase agreement with Microsoft, but Kirtley says the company’s goal is to one day get costs down to one cent per kilowatt hour.

Helion’s funders include OpenAI CEO Sam Altman. Microsoft has invested several billion dollars in OpenAI to boost the development of popular tools such as ChatGPT. Altman is Helion’s chairman and largest investor, Washington Post reports, and may have been involved in brokering Helion’s power purchase agreement with Microsoft. Kirtley narrates The Verge his company has worked closely with Microsoft’s data center group in recent years to better understand their energy needs and get Microsoft comfortable with the technology.

“Helion’s announcement supports our own long-term clean energy goals and will advance the market to establish a new, efficient method to bring more clean energy to the grid, faster,” said Brad Smith, vice president and president of Microsoft, in a press release.

But as has been the case with dreams of nuclear fusion for decades – we will have to wait and see.

Update May 10, 10 a.m. ET: This story has been updated with information about Sam Altman’s involvement with Helion and the deal with Microsoft.