Building Trust in Fusion Energy

An Open Letter from Commonwealth Fusion Systems CEO, Bob Mumgaard

The clean energy transition is the mission of our generation. Fusion energy is the solution at the scale of the climate problem we face.

Like any transformational technology, particularly one that has an unimaginable potential to impact humanity, fusion has a strong base of advocacy. But it also faces healthy skepticism from stakeholders, which is warranted given its as-yet unproven nature. Commonwealth Fusion Systems and our larger fusion industry have a collective interest in deepening credibility and trust in fusion as we advance toward commercialization and impact.

I’m writing this open letter to our peers in the fusion industry and to those commentators and journalists who watch and report on us. The title of this letter is not a mandate to “trust in fusion,” but rather a call to action for our peers to take meaningful steps with us to earn that trust and align toward basic principles.

On communicating progress

We're pursuing something so big and important that we need to measure and communicate our progress in transparent, repeatable ways. From the beginning, CFS has been committed to holding itself accountable to science, engineering, and commercial progress — and to talking about our inevitable missteps and failures as well. I want all fusion companies, research organizations, and partners to hold each other accountable in constructive ways. Press releases without proof will do more harm than good to stakeholders’ trust in fusion.

Fusion is hard. It is deeply technical, progress takes time, and results require diligent interpretation. We must all work to move away from every advance being a breakthrough, and toward a common understanding and language about where we are and where we’re heading. The industry can reduce the uncertainty and confusion by publishing research plans and results and allowing for the best minds in the world to scrutinize and criticize the findings.

CFS will continue backing up our claims with evidence. We will publish that evidence, and we’ll make that evidence available to peers, researchers, and media outlets. We’ll put that evidence into context, sharing if this is an anticipated advance or an unexpected outcome. All fusion companies should do the same to earn credibility and trust. I encourage journalists to ask for evidence from any company when they’re publishing and promoting news and breakthroughs.

The industry must not give into marketing hype. We must communicate clearly, openly, and accurately with investors, regulators, policymakers, and the general public. I encourage peers and journalists to ensure claims of progress are:

• Easy to measure: Milestones and progress should be straightforward to measure using standard techniques that are easy to interpret. When achieved, it should be unequivocal.
• Peer reviewed: Claims should be submitted to peer review and withstand the scrutiny. The norm should be peer-reviewed data.
• Public: Important, publicity-worthy developments should be demonstrable in ways that the public can observe. They should be celebrated in public.
• Easy to understand: They should signify that progress is being made in a concrete way.

Building a universal understanding of the stages

The landscape has several types of fusion power machines, but every company or concept is going to go through concrete development milestones in controlling a hot plasma effectively and then bringing power to the grid economically.

I’ve outlined below the six key milestones that all fusion concepts and companies will need to follow so that commentators and journalists can separate marketing hype from real innovation.

1. Can you produce plasmas that are stable enough to be a fuel for the fusion power machine, or is the plasma an unstable blip? The plasma must be fully ionized. Photos and data traces of the plasma provide evidence.
2. Can you heat the plasma to 10,000,000° C? This is 1keV, for electrons and ions, for those steeped in the science. There are established ways to measure this, but they’re tricky and need to be reviewed.
3. Is it a serious plasma, confined and dense enough that collisions necessary for fusion are starting to play a serious role (10^19 keV/m^3/s for those following along)? This is routinely measured with a metric called the triple product.
4. Can your plasma make actual fusion reactions that produce net energy gain? That threshold, denoted as Q>1, shows that, at the plasma level, a machine makes more heat than it took to heat it up. The plasma is an amplifier. Getting Q>1 shows a fusion machine is actually making meaningful fusion happen, not just reaching the right plasma conditions.
5. Can your fusion machine make enough power to sell the excess? This isn’t just at the level of the plasma, but rather considering the whole plant. Typically this is about electricity, and is called the “net electric” milestone. Importantly, this means the plant has to cover all its own needs and then some, it can’t just convert incoming electricity to “fusion-ified” electricity as a pass-through. This is measured in megawatts (MW).
6. Is your fusion power plant economical enough to eventually be a competitive option in any market in the world? This is about all the costs that go into building and operating the plant. This is typically measured in a levelized cost of electricity. If your power costs $50 per megawatt-hour (MWh), you win the market. If you can make $100/MWh you can at least enter it.

At CFS, we track all the concepts and companies’ progress on these stage gates. So do the national labs and many academic researchers. These milestones are similar to what the National Academies have issued and that ARPA-e has used to judge applicants. Right now there are many 1s, several 2s (mirrors, pinches, FRCs, tokamaks, stellarators, laser inertial, magneto-inertial fusion), four 3s (tokamaks, stellarators, laser inertial, MagLIF), one 4 (NIF at Lawrence Livermore National Laboratory), and no 5s or 6s. Any concept or company advancing from one level to another deserves to be celebrated. It’s a real accomplishment. The fact that in the last few years we’ve seen major movement on this scale is a huge reason those in the field are excited. Coupled with more money (public and private), helpful technologies (magnets, simulation), and great science and engineering, we should see more, including at the forefront of the scale.

On holding ourselves accountable

As fusion grows, more and more people will enter the market. This is a good thing. But it also means more pressure and more voices. Importantly, we need voices that can help distinguish the progress from the hype. There is a growing role for communicators, for influencers, and for editorialists to track the progress and check the claims. We shouldn’t expect the companies to fact-check each other — they should provide evidence for other parties to do so.

Importantly, this is one reason why CFS participates in the DOE Milestone program. This program requires companies to write down a roadmap with key objective milestones, and then the government researchers check when each milestone has been achieved. If they agree a milestone is complete, the government cuts a check. This provides the whole ecosystem with the validation that progress is indeed being made. We’re excited to start checking off milestones now that this program is announced, and we encourage everybody to publish and celebrate their milestones.

At CFS we are in a race against time, not any one company. To succeed in the energy transition, trillions of dollars will need to be deployed. This will be a huge market with room for multiple successful approaches. We’ve made tremendous progress in our brief journey. CFS has the largest base of investors who believe in fusion and believe in the approach that we’re taking. We regularly publish research so that the entire community can evaluate our approach. And as part of the community, we regularly provide tangible evidence that we’re advancing in our journey to commercialize fusion. We want and need the same credible innovation and progress coming from across the fusion industry, beyond our company alone. When earning trust in fusion, a rising tide lifts all boats.

Bob