MIT researchers tackle the economic realities of fusion power

For the past decade, scientists have proven that fusion energy is physically possible. Now, the big question is: Can it be economically viable?

MIT professors Dennis Whyte and Andrew W. Lo have created a new framework. It helps understand what's needed to make fusion energy work in the market. Their method looks at the physical resources needed for fusion and the cost of building power plants that can compete.

Making Fusion Economically Viable

Whyte, a professor of nuclear science and engineering at MIT, explained that this framework covers "all the things that come along with finding, allocating, and spending money at this scale." He stressed the importance of looking at the economics if fusion technology is to have a real impact on the world economy.

Fusion energy uses the same reaction that powers stars: light nuclei fusing together. This process creates fuel in a plasma state, often held in place by magnets or started by powerful lasers. Whyte's goal is to produce a lot of energy while also offering safe, easy-to-license, and well-located power options.

In 2022, researchers at the National Ignition Facility in California achieved a fusion reaction that produced more energy than it consumed. Venture capital has also invested heavily in the field. However, building commercial fusion energy plants still faces many challenges.

Lo noted that it's hard to turn complex scientific and engineering needs into economic outcomes. But he added, "if we don’t do that, we’re not going to get the funding we need to achieve the impact we want.”

The study, "Criteria for the economic viability of fusion power plants," is available in the Journal of Fusion Energy. The authors include Whyte, Lo, Rachel Bielajew, Maria Hancock, Riley Moeykens, and Guinevere Shaw.

Whyte is a co-founder of Commonwealth Fusion Systems, an MIT spinoff. He and Lo also co-founded Rutherford Energy Ventures, a consulting and investment firm.

The 10 Parameters for Success

The framework proposed by Whyte and Lo uses ten parameters to judge if a fusion power plant can be economically viable. Some parameters are scientific, focusing on the energy consumed and produced. Most, however, are about engineering and economics, like construction costs.

The framework draws inspiration from the 1950s Lawson Criterion. This criterion describes the conditions (temperature, plasma density, and energy confinement time) needed to get net energy from plasma fusion. It calculates "plasma Q," which is the ratio of fusion power produced to the external power needed to maintain the plasma.

Whyte explained that while the Lawson Criterion measures scientific success, their framework describes "economic Q." This is the ratio of capital gained to capital spent. For basic viability, this economic Q must be greater than one.

The parameters cover engineering aspects like power density, how efficiently fusion power turns into an economic product, and the durability of components. They also include costing and market parameters that look at expenses and returns on investment. Whyte said the framework focuses on what it takes to achieve a net-positive economic return, "but applied to practical power plant design.”

Whyte emphasized that the framework works for any fusion concept. "The physical reality of fusion is that you expend money to build the capability to produce fusion power," he said. The parameters also scale to any project size. Lo added, "It doesn’t matter whether the fusion power plant is a small or large, the bottom line is: In both cases you better have money coming out that exceeds the money going in, otherwise it’s not going to be around for very long.”

Whyte and Lo hope their paper highlights the importance of carefully accounting for all costs in fusion research. Estimating the costs of a fusion reactor is different from basic experiments, but it's something leaders in the field need to focus on more.

A Path Forward for Fusion

The authors note that new funding is entering the fusion energy industry. Commonwealth Fusion Systems recently secured a billion-dollar funding round. They aim to open their first working power plant in the 2030s in Virginia.

Lo believes that while the first commercial fusion reactor will involve uncertainties, the industry could learn by doing. This approach has helped other industries become more economical over time. He pointed out that sequencing a human genome is now a million times cheaper than it was 25 years ago. "We’re going to see the same thing, but maybe not to the same degree, in fusion energy,” Lo said.

Lo has worked to help scientific research get financial support in biotechnology. He is also launching a new MIT Sloan program called CATAPULT. It will help people translate their research into products.

For fusion, Lo said, "It’s pretty clear that economic viability is something we can start assessing now.” The authors believe their approach will help quantify the many decisions involved in building a commercial fusion plant. Whyte concluded, "When you’ve got a framework to evaluate it in a quantitative way, it tells you about the literal worth of making a particular design decision. That seems to me at this moment of fusion development absolutely critical, and what we’ve been missing.”

Deep Dive & References

Criteria for the economic viability of fusion power plants - Journal of Fusion Energy, 2024