Prime Movers Lab Webinar Series: Nuclear Fusion

A conversation with entrepreneurs and experts on trends and technologies in nuclear fusion

If we could design the ideal source of energy for mankind, what would it be? Ideally it wouldn’t take very much fuel to produce a lot of energy. The fuel would be equally distributed, so people wouldn’t have to fight over it. We’d like for the source of energy to never run out in the next billion or more years [even as energy demand grows].

Our ideal energy source would produce no CO2 or other emissions, or long-term radioactive waste. We could turn it off easily. It wouldn’t take up much land. It could run at night, and be located in any climate or part the world near where it is needed. This would be the last energy source that humans would ever need.

As Bob Mumgaard of Commonwealth Fusion Systems quite elegantly explained yesterday, nuclear fusion has this unique combination of attributes. This is why so many of us are excited by the prospect of fusion power, and the progress we’ve seen in this area.

In this episode of the Prime Movers Lab webinar series, we speak with experts from different corners of the fusion landscape on what drew them to fusion, where fusion is today, and what it will take for fusion power to become a reality. We hope you enjoy this conversation as much as we did!

[Click the link above to play the video]

Expert Panelists:

Michael Delage is the CTO of General Fusion, which is developing an economically viable path to fusion power through Magnetized Target Fusion. Founded in 2002, General Fusion is one of the first private companies established to commercialize fusion technology. Michael is an engineer and experienced technology entrepreneur passionate about solving the energy challenge. He previously co-founded and help build Energate Inc. into one of the leading home energy management technology companies in North America.

Bob Mumgaard is the CEO and co-founder of Commonwealth Fusion Systems, which was spun out of MIT in 2018. Commonwealth Fusion is using new high temperature superconductor technology to enable a significantly faster and lower cost path to tokamak (magnetic confinement) fusion systems.

Mary Woollen has spent her career managing public engagement and risk in the energy sector. She has worked with the Inertial Confinement Fusion (ICF) program at the DOE, and has deep experience working with many organizations on strategies for radioactive waste management. She has served on the Blue Ribbon Commission on America’s Nuclear Future.

Malcolm Handley left the software industry to focus on climate change, which led him to start a venture capital fund focused on investing in nuclear fusion startups. He served as Managing Partner at this firm, Strong Atomics, and most recently as a fusion technology-to-market advisor for the Department of Energy’s ARPA-E program.

Some Brief Highlights

While I highly recommend listening to the webinar and taking away what speaks to you, here are some highlights from our panelists’ responses:

Why now? What has changed the most since you began working on fusion?

• Fusion is different now because humans are focused on fusion for energy purposes. Not as a science experiment (e.g. ITER), or as a weapons project disguised as a science experiment, but with the goal of producing power in the fastest, most economical way.
• Modern computing to model fusion systems has created a toolset that universities and private companies as well as national labs can utilize. Other key technologies have evolved outside of fusion — modern controls systems, electronics, gigahertz processing capabilities —that weren’t possible 20 years ago but are now cheap. These and others have opened new pathways to commercial fusion.
• The emergence and initiative of private companies. Private companies are now working to commercialize both traditional branches of fusion, magnetic and inertial confinement, as well as the spectrum in between.
• The US government has invested $50B over the years in building up the science and technical expertise. For a period, the key figures of merit for fusion were improving faster than Moore’s Law for computing costs. What happened in the early 2000s is open to debate. However, there are reasons to believe that like the Wright Brothers at the turn of the century, we are just below a “threshold of believability”.

How should we think about what fusion technologies will look like?

• Fusion entrepreneurs have great analogies to describe the systems that they are building. For magnetic confinement fusion (MCF) systems like Commonwealth’s, if you can get a plasma hot enough, dense enough and insulated enough, it will make more power from fusion than it took to heat the plasma up. Commonwealth is creating a magnetic “thermos” to keep the fusion reactions going. On the inertial confinement (laser) side of things, the goal is to make the fusion reactions happen so fast that the plasma can’t get out of it’s own way. Both follow the same physics.
• Rather than trying to keep the plasma hot and stable at low density with magnets, or create really high densities for short amounts of time with lasers, General Fusion is making the “diesel engine” of fusion systems. They start with a magnetized plasma and compress it in pulses. Like a diesel engine, compression heats the plasma fuel, the fuel ignites, and the cycle repeats. They also have a clever way of containing the fusion reaction inside liquid metal (you’ll have to listen to Michael’s description of that one).
• The amount of power that each fusion plant is designed to generate ranges from a few hundred megawatts (MW) to a gigawatt (GW). Bigger is generally better for fusion, from a cost and insulation perspective. However, bigger isn’t always better from a market point of view. There is a sweet spot in the 300–400 megawatt range (about half the size of an average natural gas power station in the US) that private fusion companies are incentivized to hit.
• The capital costs for a fusion power plant are expected to be a few dollars per watt, up to $5/watt at the high end. While at the upper end of this range, the upfront capital costs would be similar to nuclear plants, there many are reasons to think that nuclear fusion can be (and it must be) cheaper. With nuclear fission plants, there is an overriding safety concern of a runaway reaction driving every design decision. For a fusion power plant, the design starting point is totally different.

What work still needs to be done? What technical, economic or other challenges do you see?

• Most fusion companies are planning to use deuterium (common, in seawater and chemistry labs) and tritium (not common today, but produced or “bred” in fusion reactions) as fuel. More work is needed to de-risk tritium breeding, and the need for tritium breeding will require fusion plants to be a minimum size.
• Unlike the markets for other emerging technologies, the markets for fusion power—the world’s electricity markets — are well-known and established.
• In response to whether fusion will be able to compete with renewable forms of energy: we need as much low carbon energy as we can get from all sources. We also need to keep in mind that the lowest reported cost of producing power from renewables is not the same as distributing reliable electricity to all consumers. As the amount of renewables on the grid increase, the cost of associated storage and transmission increase (differently, depending on the region and locality). Many areas are difficult or impossible to serve with renewables alone. Fusion promises to be power dense, dispatchable and not tied to limited resources.
• In the past, people haven’t wanted to participate in (or be sited near) technologies that they see has high risk. Nuclear fission is notoriously hard from a PR perspective. On the other hand, the ICF program at Livermore didn’t have the same obstacles because the public were engaged and trust was built early. By starting early, we can engage and prevent the perception that fusion represents an extreme risk, like nuclear fission.
• Project economics, public perception and the regulatory pathways to operation ultimately all need to line up. If these can be achieved, the outlook looks really positive. Polls show that people want energy independence, decreased greenhouse gas emissions, and renewable energy sources.

If you’d like to dive deeper, many of the topics we touched on in this webinar are covered in more detail in our blog posts on different aspects of fusion. These include an overview on [what the heck is] fusion, and descriptions of the two main approaches to fusion: magnetic confinement fusion (fusion with magnets) and inertial confinement fusion (fusion with lasers). For a basic refresher for all in your household, check out Prime Movers Lab Kids Corner: Nuclear Fusion!

Fusion isn’t something a lot of people know much about. If you went out and polled people on the street, most people wouldn’t know about fusion or be able to explain it. You don’t want fusion to be the best kept secret, but at the same time you don’t want to over-promise and under deliver. Finding that space in the middle, while doing more outreach to increase understanding, is important.

A huge thank you again to our panelists for sharing their time and knowledge with the community — we are very grateful. Thank you for joining us in learning more about this space!

Note: In this post, I have done my best to paraphrase the panelists’ responses to questions while maintaining accuracy. The statements in italics, in particular, are owed to specific individuals. All responsibility for errors made paraphrasing and summarizing this conversation is mine and not theirs! Once again encourage you to listen to the webinar for the full context behind each comment.

Prime Movers Lab invests in breakthrough scientific startups founded by Prime Movers, the inventors who transform billions of lives. We invest in seed-stage companies reinventing energy, transportation, infrastructure, manufacturing, human augmentation and computing.