Cracks are starting to form on fusion energy’s funding boom


It happens in every emerging industry: founders and investors push toward a common goal, until the money starts to roll in and that shared vision begins to diverge.

Cracks are emerging in the fusion power world, which I saw firsthand at The Economist’s Fusion Fest in London last week. It didn’t dampen the overall buoyant mood, lifted by fusion startups’ fundraising haul of $1.6 billion in the last 12 months. But people had differing opinions on two key questions: When should fusion startups go public? And are side businesses a distraction?

Going public was at the top of everyone’s minds. In the last four months, TAE Technologies and General Fusion have announced plans to merge with publicly traded companies. Both stand to receive hundreds of millions of dollars to keep their R&D efforts alive, and investors, some of whom have kept the faith for 20 years, finally see an opportunity to cash out.

Not everyone is in agreement. Most of those who I spoke to were worried these companies were going public far too early and that they hadn’t achieved key milestones that many view as vital in judging the progress of a fusion company.

First, a recap: TAE announced its merger with Trump Media & Technology Group in December. Though the deal isn’t yet completed, the fusion side of the business has already received $200 million of a potential $300 million in cash from the deal, giving it some runway to continue planning its power plant. (The remainder will reportedly land in its bank account once it files the S-4 form with the U.S. Securities and Exchange Commission.)

General Fusion said in January that it would go public via a reverse merger with a special purpose acquisition company. The deal could net the company $335 million and value the combined entity at $1 billion. 

Both companies could use the cash.

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Before the merger announcement, General Fusion was struggling to raise funds, and around this time last year it laid off 25% of its staff as CEO Greg Twinney posted a public letter pleading for investment. It received a brief reprieve in August when investors threw it a $22 million lifeline, but that sort of money doesn’t last long in the fusion world, where equipment, experiments, and employees don’t come cheap.

TAE’s position wasn’t quite as dire, but it still required some funds. Pre-merger, the company raised nearly $2 billion, which sounds like a lot, but keep in mind the company is nearly 30 years old. What’s more, its valuation pre-merger was $2 billion, according to PitchBook. Investors were breaking even at best.

Neither company has hit scientific breakeven, a key milestone that shows a reactor design has power plant potential. Many observers doubt they’ll hit that mark before other privately held startups do. One executive told me, if they were in those shoes, they’re not sure how they would fill time on quarterly earnings calls if the companies didn’t hit scientific breakeven soon.

If TAE or General Fusion doesn’t deliver results, several people feared the public markets would sour on the entire fusion industry.

Now, not all may be lost. TAE has already started marketing other products, including power electronics and radiation therapy for cancer. That could give the company some near-term revenue to placate shareholders. General Fusion, though, hasn’t revealed any such plans.

And therein lies another divide: fusion companies remain split on whether they should pursue revenue now or wait until they have a working power plant.

Some companies are embracing the opportunity to make money along the way. Not a bad strategy! Fusion is a long game, so why not improve your odds? Both Commonwealth Fusion Systems and Tokamak Energy have said they’ll be selling magnets. TAE and Shine Technologies are both in nuclear medicine.

Other startups are worried that side hustles could become a distraction. Inertia Enterprises, for example, told me that they’re laser-focused on their power plant. That jibes with what another investor told me months ago: — they were worried that fusion startups could get distracted by profitable, but tangential businesses and fall off the lead. 

There wasn’t consensus on the right time to go public either. I heard a few proposed milestones. Some believe startups should first reach that scientific breakeven milestone, in which a fusion reaction generates more energy than it needs to ignite. No startup has achieved that yet. The other possibilities are facility breakeven — when the reactor makes more energy than the entire site needs to operate — and commercial viability — when a reactor makes enough electrons to sell a meaningful amount to the grid.

We may have an answer to that question sooner than later. Commonwealth Fusion Systems expects it will hit scientific breakeven sometime next year, and some think the company might use that as an opportunity to go public.

Struggling fusion power company General Fusion to go public via $1B reverse merger


Last year, fusion power startup General Fusion was struggling to raise funds, laying off at least 25% of its staff before receiving a $22 million lifeline investment while it figured out how to keep the company afloat.

Today, General Fusion revealed its survival plan: it will go public through a reverse merger with an special purpose acquisition company, Spring Valley III, combined with additional investment from institutional investors. It’s a significant change in fortunes for a company whose CEO wrote a public letter just last year pleading for funding.

If the deal closes as planned, General Fusion could receive up to $335 million from the transaction, more than double what it was reportedly seeking to raise last year before it landed the $22 million lifeline.

The transaction will value the combined company at about $1 billion, General Fusion said. Before the merger was announced. The fusion startup, which was founded in 2002, had previously raised over $440 million, according to PitchBook.

General Fusion plans to use the money to complete its demonstration reactor, Lawson Machine 26 (LM26). The device uses an approach called “inertial confinement,” which works by compressing a fuel pellet until its atoms fuse together, releasing energy in the process. The National Ignition Facility used inertial confinement in its successful fusion experiments, using lasers to bombard the fuel pellets to unleash the compressive force.

LM26 eschews the lasers, though. Instead, it uses steam-driven pistons that drive a wall of liquid lithium metal inward to compress the fuel pellet. That liquid lithium then circulates through a heat exchanger, which generates steam to spin a generator. By avoiding expensive lasers or superconducting magnets, which are required in other fusion reactor designs, General Fusion hopes to build a fusion power plant for less money. But first the company has to prove its approach is viable.

Last year, before it revealed its financial problems, General Fusion said that in 2026, LM26 would hit scientific breakeven, in which a fusion reaction generates more power than was required to start it. Scientific breakeven is a key milestone, though distinct from and easier to attain than commercial breakeven, in which fusion reactions release enough energy to export electricity to the grid. General Fusion did not reply to a request asking if its timeline had change.

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The acquisition company, Spring Valley, is something of a specialist in reverser mergers with energy companies. It previously took NuScale Power, a small modular nuclear reactor company, public in a deal whose stock price has since fallen more than 50% from its peak last year. The firm is also in the midst of completing a merger with Eagle Energy Metals, a uranium mining company that’s also supposedly developing its own SMR.

General Fusion isn’t the first fusion company to go public. In December, TAE Technologies announced it would merge with Trump Media & Technology Group in a deal valuing the combined company at more than $6 billion.

The common thread connecting these deals is data centers, of course. They’re expected to consume nearly 300% more power by 2035, according to BloombergNEF, and General Fusion explicitly points to rising data center energy demand in its merger announcement

But the company also pointed to broader electrification trends, including EVs and electric heating, that could increase overall electricity demand by up to 50% by 2035. It’s a reminder that, while the Trump administration has cast doubts on an electrified future, other countries are charging ahead. While General Fusion may face technological challenges, trends in the energy world suggest that if it can deliver fusion power at a reasonable cost, it will find plenty of willing buyers.