With $10T on the line, 6 fusion investors explain why they’re all in

Fusion power could be considered the quintessential venture capital bet: It’s expensive and risky, but the potential rewards are enormous. The world paid $10 trillion for energy last year, according to the International Energy Agency (IEA), so even a single-digit percentage of that pie would generate revenues in the tens of billions. Oh, and a commercially successful fusion power plant would change the world.

But that’s just part of the reason why investors have been diving deep into fusion power in the last few years. “There is more confidence than before [in] fusion machines getting not only to ‘scientific breakeven,’ which is getting more energy out of the fusion reaction than the energy that it takes to get to the fuel, but also getting enough excess energy to make for viable commercial power plants,” Phil Larochelle, partner at Breakthrough Energy Ventures, told TechCrunch+.

The field achieved a milestone late last year when the Department of Energy’s National Ignition Facility announced that it had created a fusion reaction that produced more power than was required to spark the fuel pellet. There’s still a long way to go, but net-positive controlled fusion is no longer just theoretical. “The industry is slowly leaving the lab and moving into the engineering phase,” said Wal Van Lierop, founding partner at Chrysalix Ventures.


We’re widening our lens, looking for more investors to participate in TechCrunch surveys, where we poll top professionals about challenges in their industry.

If you’re an investor and would like to participate in future surveys, fill out this form.


Momentum has been building over the last decade, though. “This recent renaissance in fusion has seen a blossoming of diverse technologies,” said Thai Nguyen, partner at MCJ Collective.

Breakthroughs in superconducting magnets coupled with exponential advances in computing power and machine learning have transformed the field seemingly overnight. More powerful and efficient magnets helped breathe life into the field, and the computing advances allowed researchers to simulate a potential reactor’s conditions in a fraction of the time previously required. Suddenly, small teams could feasibly design and tweak reactors.

“All of this adds up to an increased pace of innovation across a range of fusion approaches,” said Alice Brooks, principal at Khosla Ventures.

As private funding has rushed in, it has also allowed teams to not only refine existing reactor designs, but also explore alternatives that had previously been dismissed. “The transition to private science funding with a focus on commercial relevance has put experimental (and physical) heft behind a lot of concepts that had been percolating in academia for years, but largely couldn’t get funded given the gravity of tokamaks and laser inertial fusion mega-projects,” said Joshua Posamentier, managing partner at Congruent Ventures.

That doesn’t mean commercially viable fusion is a sure thing or that investors can expect returns on the usual timelines. On the contrary, “if you have a traditional five- to seven-year time horizon venture fund, it is difficult for a fusion investment to make sense,” Katie Rae, CEO of The Engine, said.

Rather, firms are investing on much longer timelines, in part because it’s what the sector requires and in part because the potential market is enormous. “The economic opportunity justifies the timeline,” Rae said, adding that investment figures are likely to increase in the coming years. “I expect we’ll see bigger amounts going into startups as they accomplish their next set of milestones.”

Read on to learn more about what these investors expect from fusion, when they expect the technology to become commercially viable, and the balance that academia needs to strike with venture to truly push the envelope.

We spoke with:


Katie Rae, CEO and managing partner, The Engine

Fusion has broken a lot of promises in the past. What’s different this time? 

It’s easy to look from the outside and believe the adage of “fusion is always 30 years away.” But if you dig into the research, there has been a steady beat of scientific progress and accomplishments in fusion since research really began in the 1950s. In fact, the progress has actually progressed faster than Moore’s law. What’s different now versus earlier is the confluence of a few key workstreams.

There have been a few significant milestones achieved in the industry in the last few years. In September 2021, Commonwealth Fusion Systems demonstrated, at scale, an entirely new type of superconducting magnet technology that enables a new commercial pathway for fusion energy.

In December 2022, the National Ignition Facility at Lawrence Livermore National Lab demonstrated a fusion experiment that got more energy from the plasma than it took to heat it, or Q>1, for the first time in history. This is an example of the robustness and advancement of the simulation tools that exist; this was a long predicted result and confirms much about plasma and fusion physics. Additionally, there has been significant innovations and progress in ancillary technologies, such as materials, advanced simulation and computational capabilities, and electronic components, that enable new capabilities and technical development on more accelerated timelines.

Which approach to fusion do you think holds the most promise and why (e.g., tokamak, sheared-flow stabilized Z-pinch)?

In the distant future, I think there will be a robust fusion industry where there are many different architectures. The question is, which has the most promise to be commercial today and to hit the timelines needed to meet 2050 decarbonization goals?

Ultimately, it comes down to which concepts are scientifically mature, where a commercial entity using that approach is focused on retiring engineering and execution risk, rather than more science risk. A useful tool to assess that is the triple product; it is a way to measure how mature a fusion concept is. There is a really useful ARPA-E paper that provides an overview on this. Ultimately, I believe that tokamaks using magnetic confinement are the leading design architecture. I also think stellarators are another concept that holds promise. I believe in supporting the continued research of a large variety of fusion approaches; it’s just a matter of which ones have hit a point where commercialization makes sense.

Given historically long time horizons, how do you fit fusion investments into a venture time scale? 

Certainly, if you have a traditional five- to seven-year time horizon venture fund, it is difficult for a fusion investment to make sense. A key piece to The Engine’s strategy was recognizing, however, that there are certain types of companies that are truly rooted in a deep scientific breakthrough and need longer time horizons to get to market — but that the markets they will address will be enormous. The argument around the fusion market is whether it is a $10 trillion market or a $30 trillion market. So, the economic opportunity justifies the timeline.

When do you think the first fusion power plant will become commercially viable? What makes you confident in that date? 

I am an investor in Commonwealth Fusion Systems and believe they will be first to market. They aim to have their first commercial fusion power plant on the grid in the early 2030s. I am confident in this approach because I have watched the team execute and build a track record of doing what they say they would.

They built their revolutionary full-scale magnet technology in three years, during the pandemic, right when they said they would. And they are now 2.5 years into building a large-scale demonstration plant that will demonstrate Q>1, and I get to track that as it’s happening. Ultimately, for things that are in the world of infrastructure, a big piece of risk retirement is not only your science and engineering, but [also] your ability to execute on time and on budget.

Finally, like many companies in tough tech, there is nothing like a multidisciplinary team that is laser-focused on a mission. When you have a mission worthy enough, people are capable of extraordinary things. This is a huge advantage that fusion and other tough tech companies have over many other corporations: a meaningful mission to continue to drive you day in and day out.

Fusion investment is down significantly this year after a blockbuster 2021 and a quieter 2022. What does that tell us about the industry? 

These companies are focused on heads-down work and reaching their next milestones before their next raise. Fusion companies have longer development timelines than the typical startup, and therefore their funding cycles are not typically in the 12- to 18-month time frame like other technologies. So I expect we’ll see bigger amounts going into startups as they accomplish their next set of milestones.

With that said, despite not [being] in the several hundred million or billion size, there was significant investment in fusion in 2022 and 2023 across many fusion companies, some at early-growth stage and others at seed stage. I think this is important, especially in the backdrop of the market: that even then, fusion investment continued.

Given recent regulatory comments from the U.S. government, are improvements to the fusion regulatory landscape a potential unlock for more investment? 

Undoubtedly, the regulatory decisions in both the U.S. and the U.K. are significant for two reasons: (1) They provide regulatory certainty for investors, whereas prior it was an unknown and therefore a different kind of risk, and (2) the decisions that have been made are hugely impactful on the economics and scalability of fusion power plants. The fusion license process will take one to two years and will cost a few million dollars. In contrast, the fission license process in the U.S. takes on the order of 10 years and $1 billion.

How much more money will fusion startups need to raise to get to commercialization? Do any have enough capital to get all the way there today? 

The first commercial deployments will likely cost in the few billions. Fusion companies could benefit from public-private partnerships to get there. DOE’s Loan Program Office can also be an asset in first-of-a-kind construction.

What’s driving the pace of progress in the fusion industry? 

A few things are driving the pace: The influx of private capital, open mindedness from government about non-ITER concepts (e.g., DOE Fusion Milestone program, Nuclear Regulatory Commission’s recent decision to regulate fusion reactors separately from fission reactors), companies like Commonwealth Fusion Systems paving the path forward to build an ecosystem around fusion startups.

What is the balance between academia and industry when it comes to pushing the envelope on fusion tech today?

Many startups are collaborating with academia to push technology development forward — for example, Commonwealth Fusion Systems with MIT or more recently, Proxima Fusion with Max Planck Institute. This absolutely needs to continue and deepen. I anticipate this will be amplified by the new DOE milestone program.

Collaborations like this are critical, not only to continue to develop new innovations and improve understanding, but also to continue to build a talent pool for the fusion industry. It is interesting to observe more fusion research programs being stood up at universities, more cross-functional research happening across universities rather than purely in the nuclear engineering department, and more applied research being pursued.

Phil Larochelle, partner, Breakthrough Energy Ventures

Fusion has broken a lot of promises in the past. What’s different this time?

The key first step to commercial fusion is to prove that you can get more energy out of a fusion reaction than is required to drive the fusion reaction, also known as reaching “energy breakeven.” Starting in the 1960s, several concepts made steady progress toward breakeven. See this paper for a description of those historical results.

Breakeven was accomplished for the first time in December 2022 at the National Ignition Facility in California using lasers and inertial confinement. Other concepts in magnetic confinement have also made it close (tokamaks to within a factor of two) of energy breakeven.

The scaling laws for how these machines operate are now better understood, and so there is more confidence than before of these machines getting not only to “scientific breakeven,” which is getting more energy out of the fusion reaction than the energy that gets to the fuel, but also getting to enough excess energy to make for viable commercial power plants.

In addition to the breakeven milestone on lasers, component-level advances, such as high-temperature superconducting magnets, have changed the size and economics of these approaches to now provide a path to economical energy and electricity production. Increasing government support through a more favorable regulatory framework and a DOE cost-share program as well as more discussion of private capital financing models (see here) are all favorable tailwinds for moving toward commercialization and are part of the “why now” story.

Which approach to fusion do you think holds the most promise and why (e.g., tokamak, sheared-flow stabilized Z-pinch)?

We have made investments in four fusion approaches: high-temperature superconductor tokamak (Commonwealth Fusion Systems), high-temperature superconductor stellarator (Type One Energy), lasers (Xcimer Energy) and sheared flow stabilized Z-pinch (Zap Energy).

Each has the possibility of getting working commercial reactors to deliver electrons on the grid in the 2030s. All four of the companies were also recipients of the eight U.S. DOE milestone-based cost-share awards (see here).

Given historically long time horizons, how do you fit fusion investments into the venture time scale?

We see pathways for each company BEV has invested in to get to fusion electrons on the grid in the 2030s. It remains to be seen when that could lead to liquidity for investors, so investors have to decide whether that is a match for their time scale and requirements.

When do you think the first fusion power plant will become commercially viable? What makes you confident in that date?

Early to mid-2030s is the goal for first electrons on the grid. Cost will continue to decline after the first power plants get to scale and wide-scale commercial viability. This is expected to continue throughout the 2030s and 2040s.

Fusion investment is down significantly this year after a blockbuster 2021 and a quieter 2022. What does that tell us about the industry?

The overall news for fusion has been positive on a few fronts (National Ignition Facility, Nuclear Regulatory Commission, DOE cost-share program), so the quieter 2022 may be a function of market trends rather than a reflection on fusion.

How much more money will fusion startups need to raise to get to commercialization? Do any have enough capital to get all the way there today?

Each of our companies will likely require over $1 billion to get to commercialization. All will require additional capital.

What’s driving the pace of progress in the fusion industry?

Several factors:

  • Scientific progress: Results from the National Ignition Facility and Germany’s W7-X have been catalysts for laser and stellarator companies, respectively.
  • Government funding: DOE cost-share program and ARPA-E have helped advance several fusion projects.
  • Regulatory clarity will be an accelerant.
  • New sources of private capital (e.g., Japanese company investments in Kyoto Fusioneering) are helping move things along.

Joshua Posamentier, managing partner, Congruent Ventures

Fusion has broken a lot of promises in the past. What’s different this time?

Fusion has been a field of extremes for decades. On one side, you have huge government research programs like ITER and the National Ignition Facility. On the other side (at least until recently) you had amateurs and hobbyists claiming cold fusion in a basement. The dichotomy has been tough to get through.

The transition to private science funding with a focus on commercial relevance has put experimental (and physical) heft behind a lot of concepts that had been percolating in academia for years, but largely couldn’t get funded given the gravity of tokamaks and laser inertial fusion mega-projects. The real breakthroughs were less about big projects like TAE Technologies or Commonwealth Fusion Systems and more focused on the novel architectures that could achieve either dramatic progress or else fail fast — all for a scale of investment tractable to VCs. This group comprises Helion Energy, Avalanche Energy Designs, Zap Energy, etc. There has also been an influx of engineering talent with a commercial focus as compared to the big government research projects staffed purely by academics whose focus was not commercialization but research.

Which approach to fusion do you think holds the most promise and why (e.g., tokamak, sheared-flow stabilized Z-pinch)?

I’m pretty biased toward Avalanche’s orbitrap architecture. It yields the smallest commercially interesting reactor design while ultimately enabling aneutronic reactions like PB11. Other architectures like Z-pinch and pulsed linear accelerators are also interesting, but because they’ve got the ability to demonstrate commercially relevant net gain with a relatively limited amount of investment.

In contrast, Commonwealth Fusion Systems, General Fusion, TAE Technologies, Realta Fusion and the other stellarator and tokamak designs have relatively high minimum power designs [that] require commensurately huge investment just to demonstrate, never mind scale. From a venture perspective, I think the mega-scale architectures are challenging on a risk-adjusted returns basis. Designs that are relatively cheap to test and fast to build and iterate are a lot more attractive to our investment model. Once proven, I think it’s also easier and more tractable to build smaller systems than large systems capable of generating 500 MW to over a gigawatt [enough to power 375,000–750,000 homes], especially given transmission congestion issues and siting challenges.

Additionally, I think there’s value to going beyond D-T [deuterium–tritium] fusion as well. It opens up the fuel source, potentially eliminating the need for tritium handling and dropping cost by using alternative fuels like Boron-11.

Given historically long time horizons, how do you fit fusion investments into a venture time scale?

Clearly opinions differ, but my take is that limited venture dollars need to direct new technologies materially at every round. If the quanta of dollars necessary for an early step are too big, then the venture math around dilution, valuation, ownership and future step-up won’t line up well with our returns expectations or our LPs’.

The difference in time between these small, modular reactor designs versus giant systems like tokamaks, stellarators or spinning balls of lead is huge. There may be forward progress, but if a net gain system for one topology is going to cost $500 million to $1 billion versus one-twentieth of that and time frames of years versus months, it’s easier to see where you’d want to steer those venture dollars.

When do you think the first fusion power plant will become commercially viable? What makes you confident in that date?

That’s a much better question than net gain. My best guesstimate is before 2032 for the first commercial operation. This could be earlier if the DOD decides to procure and deploy on-base for energy security.

Fusion investment is down significantly this year after a blockbuster 2021 and a quieter 2022. What does that tell us about the industry?

I think that’s more of an indicator of how extreme 2021 was rather than anything 2022/2023 specific. I expect, like any emergent hard tech sector, to see some fallout (bad pun!) from some of the earlier funded fusion companies that couldn’t make it to early milestones for whatever reason. But at least a handful that raised in ’21 and ’22 raised a war chest that will take them into late ’24 or even ’25. There’s not enough to make that a smooth investment deployment curve, so I expect it to continue to be lumpy.

Given recent regulatory comments from the U.S. government, are improvements to the fusion regulatory landscape a potential unlock for more investment?

I think these things all take time to percolate through the startup community and the investment community. But the fusion rules announced by the Nuclear Regulatory Commission a couple of months ago are groundbreaking and fundamentally reduce one of the biggest risks these companies face and that fission companies still struggle with.

How much more money will fusion startups need to raise to get to commercialization? Do any have enough capital to get all the way there today?

This is difficult to say. I think Helion is the only one even hinting that they’ve enough to get to a net gain commercially relevant (though probably not really commercial) demonstrator. I think Commonwealth Fusion Systems may have enough to show net gain operationally, but that plant won’t be commercially sensible. So it’ll take a lot more money, though with a huge range. Companies like Avalanche and Zap will need far less than Helion, which will need less than Commonwealth or any of the other stellarator/tokamak companies from what I’ve seen.

What’s driving the pace of progress in the fusion industry?

I think it’s a combination of ubiquitous compute democratizing nuclear simulations. When I studied physics in the ’90s and did HPC research, this capability was only found at the national labs and very scarce, usually used to simulate massive particle physics experiments and the aging nuclear stockpile. Now it’s an AWS click away (and there’s an incredible code base and talent base that’s come of age).

What is the balance between academia and industry when it comes to pushing the envelope on fusion tech today?

That’s actually a blurry line. I don’t think I’ve met a fusion startup that didn’t have deep ties (entanglements?) with a university or national lab. I think this is a huge win: Private efforts need an influx of talent and knowledge, and academic efforts need the oomph of entrepreneurs pushing the envelope. It’s a win-win for the field and will create a virtuous cycle.

Alice Brooks, principal, Khosla Ventures

Fusion has broken a lot of promises in the past. What’s different this time?

Historically, many efforts stalled due to technical limitations or lack of funding. Several factors are now coming together to accelerate progress across multiple fusion approaches: advances in HTS magnets and supercomputing, increased private and public funding, demonstrable proof in experiments and, most important, the most talented graduates are going into this area. All of this adds up to an increased pace of innovation across a range of fusion approaches.

Which approach to fusion do you think holds the most promise and why (e.g., tokamak, sheared-flow stabilized Z-pinch)?

We are excited about multiple approaches and have already backed two: Commonwealth Fusion Systems (tokamak) and Realta Fusion (mirror). We continue to evaluate others and see room to back additional complementary approaches.

Given historically long time horizons, how do you fit fusion investments into a venture time scale?

At Khosla Ventures, our investment philosophy is to come in early on bold and impactful bets. We were the first check into Block (Square), Impossible Foods and OpenAI. We have a very long-term horizon, often longer than 10 years. This gives us the ability to be patient in our investments to ensure they have a meaningful impact on society.

When do you think the first fusion power plant will become commercially viable? What makes you confident in that date?

Commonwealth Fusion Systems is on track to have ARC, the world’s first fusion power plant, operational in the early 2030s.

Fusion investment is down significantly this year after a blockbuster 2021 and a quieter 2022. What does that tell us about the industry?

Total investment doesn’t tell the full story — 2021 had a couple of mega rounds that boosted total VC funding in the space. However, in the past two years, we’ve seen the pace of new company formation accelerating dramatically. Many of these companies have raised early-stage rounds and should attract further investment as they make progress.

The DOE’s recent announcement about its milestone program is just the first of a large amount of public funding to come over the next few years. This was one that both Commonwealth Fusion Systems and Realta Fusion benefited from, and I expect to see more happening here.

Given recent regulatory comments from the U.S. government, are improvements to the fusion regulatory landscape a potential unlock for more investment?

Fusion is a massive leap in clean energy with the ability to transform the world. This effort will require private and public involvement; any moves made to get us on a positive trajectory with fusion are worthwhile and valuable.

How much more money will fusion startups need to raise to get to commercialization? Do any have enough capital to get all the way there today?

Fusion is expensive, and depending on the approach, it could cost in the hundreds of millions to billions of dollars for any approach to get to commercialization. This is why we need all of the support the field can get from private to public, from academics to industry. Only then can we make a meaningful change in energy.

What is the balance between academia and industry when it comes to pushing the envelope on fusion tech today?

Both of our bets in fusion have been on companies with strong academic ties: Commonwealth Fusion Systems with MIT and Realta Fusion with the University of Wisconsin–Madison. CFS was started by Bob Mumgaard from MIT and Realta by Cary Forest from University of Wisconsin. They both are able to attract the smartest talent from these places to join their companies.

Wal van Lierop, founding partner, Chrysalix Venture Capital and board member, General Fusion

Fusion has broken a lot of promises in the past. What’s different this time?

Lots of the science has been proven. General Fusion has proven out most individual elements of their system; now we need to bring it all together. The industry is slowly leaving the lab and moving into the engineering phase.

Increasingly more energy transition specialists are convinced we cannot achieve net-zero by 2050 with just solar, wind, biomass and batteries. The world needs more to electrify megacities and the hard-to-abate industries (chemicals, steel, concrete, aviation, etc.).

The race is on to replace many gas-fired power plants in Europe, which under the Paris Agreement will have to be replaced by the 2030s. Plus to ensure we stop the still rapid growth of coal-fired power plants in China and India.

Significant money has been raised for private fusion companies in the past years, and many proven entrepreneurs have joined fusion startups, while machine learning and AI are helping accelerate development.

Which approach to fusion do you think holds the most promise and why (e.g., tokamak, sheared-flow stabilized Z-pinch)?

General Fusion’s Magnetized Target Fusion, and/or Zap Energy’s Z-pinch seem to be the front-runners. They both are attractive approaches that have received interesting third-party validation. All others will likely run into significant problems, in particular because of “first wall” problems (contamination of the wall of the reactor that causes mass failure not allowing continuous operation).

Given historically long time horizons, how do you fit fusion investments into a venture time scale?

This is not for the faint of heart. Even today, while many people talk about fusion, there are very few check writers. It is like carbon until about five years ago: Many people talked about it, but very few wrote significant checks. It is still hard to get significant funding without the involvement of a Silicon Valley billionaire.

When do you think the first fusion power plant will become commercially viable? What makes you confident in that date?

In about 10 years. Governments will soon realize the urgency of finding a real solution for the gap toward net zero by 2050. As a result, we will, in the next few years, probably see the emergence of national fusion champions in the U.S., U.K., Canada, China. More money and intense competition to be the first to market will help achieve the early 2030 timeline.

Fusion investment is down significantly this year after a blockbuster 2021 and a quieter 2022. What does that tell us about the industry?

Not a lot about the industry. It’s more about capital markets. After the recent stock market collapse and interest rate hikes, investors have become more cautious again.

Given recent regulatory comments from the U.S. government, are improvements to the fusion regulatory landscape a potential unlock for more investment?

The regulatory development separating fusion from fission last year in the U.K. and now the U.S. will have an important impact, but [it won’t] unlock much capital shortly.

How much more money will fusion startups need to raise to get to commercialization? Do any have enough capital to get all the way there today?

On average, the costs are coming down, but most fusion startups are still quite capital intensive and need at least $1 billion to a demo-plant, followed by at least another billion to commercialization, but more likely a multiple of that. Many fusion startups will need to become much more capital efficient, not just to bring their first plant to the market, but in particular to ensure they can do that with low-cost power. Three to 5 cents per kWh is where they need to be. (For comparison, the SMR NuScale recently reported their construction cost had more than tripled compared to their budget and now seemed to have a price outlook of ~70 cents. If true, that would price them out of most markets.)

What’s driving the pace of progress in the fusion industry?

The realization that climate change is real, and the world needs more than solar, wind, biomass and batteries for a successful energy transition. Purpose-driven scientists and businesspeople. Scientific progress in related subjects: plasma science, computer science innovation, sensors, AI and machine learning.

What is the balance between academia and industry when it comes to pushing the envelope on fusion tech today?

The biggest push comes from the startup part of the industry. Academia is slower, more often playing roles in validation and advice than being in the thick of the most exciting developments.

Thai Nguyen, partner, MCJ Collective

Fusion has broken a lot of promises in the past. What’s different this time?

Foremost, the escalating climate crisis has created renewed context and a raison d’être for fusion energy, despite the technical challenges that have made commercial-scale fusion elusive. While historically academia and governments — through global efforts like ITER — have been the driving force behind fusion development, we’re now seeing these efforts complemented by a new crop of private-sector fusion startups.

This recent renaissance in fusion has seen a blossoming of diverse technologies, and the role of private capital, ideally, ensures only the most demonstrably promising solutions continue to receive financial backing. In addition, improvements in superconducting magnets (e.g., in magnetic fusion confinement) and high-compute simulations are some of the material developments paving the way for advancements in the field. And of course, last year’s watershed milestone at Lawrence Livermore National Laboratory represents not only a major scientific achievement, but also a catalyzing event that will galvanize public interest in fusion for years to come.

Given historically long time horizons, how do you fit fusion investments into a venture time scale?

We consider what key milestones are achievable within the typical life of a fund and whether those are significant enough [to open] the path toward commercial-scale fusion further down the line. While fusion is inherently a high-risk category, if the ultimate outcome is achieved, it offers uncapped upside from both a returns and impact perspective.

Fusion investment is down significantly this year after a blockbuster 2021 and a quieter 2022. What does that tell us about the industry?

Given venture investment at large, including in climate tech, is lower than the highs seen in 2021, it shows that fusion, as a category, is not immune to the broader effects of the macroeconomic environment. Notwithstanding, I don’t believe this signals that investors have become disinterested in the space, and I would expect a rebound over time.