ARPA-E Bets Big on Fusion: Director Conner Prochaska on the Agency's Record $135 Million Commitment

At the ARPA-E Energy Innovation Summit last week, ARPA-E Director Conner Prochaska announced a $135 million commitment to fusion over the next 18 months, the largest fusion funding commitment in the agency's history and roughly equal to everything ARPA-E has directed towards fusion since it entered the space with the ALPHA program in 2014. I sat down with Prochaska on the sidelines of the summit to discuss the announcement.

Why the big bet? "The question is no longer whether fusion is possible," Prochaska said. "The question is how fast we get fusion-generated power on the grid, and whether America leads that achievement." The remaining technical barriers, he noted, "are often risky or pre-competitive for any single company to tackle alone," which is exactly the space ARPA-E was built to fill. "Private capital scales what it can already see," Prochaska said. "ARPA-E funds what the market can't yet price or predict."

The track record supports the case: ARPA-E's $134 million in prior fusion funding helped unlock over $1.5 billion in private capital and spun out seven companies (and counting). Andrew Holland, head of the Fusion Industry Association, put it simply: "It's not an exaggeration to say that much of the growth in private fusion investment and ambition can be traced back to ARPA-E."

Following the Playbook That Works

The natural first question: does ARPA-E already know what it wants to fund?

Prochaska said the agency has identified promising areas (power conversion, spin-polarized fuels, and advanced materials among them) but stressed that no decisions have been locked in. The proven ARPA-E model, where program directors develop and shape specific programs, will remain the driving force.

"We didn't go into this blindly. I wanted to make sure that the program directors we had in fusion at DOE and at ARPA-E thought there was a 'there' there," Prochaska said. "I didn't want to just throw this out there without anybody saying there's a need for ARPA-E-type research still to be done. And the answer was a resounding yes."

Prochaska was clear that it's about finding the right talent, not filling slots. "It's not a pure number, It's the right people to come in." He added that, "ARPA-E continually recruits Program Directors. The position is designed with term limits to ensure a steady flow of new ideas and new perspectives and to enable the agency to engage experts who can tackle the most pressing energy challenges of the day.”

As for why the ARPA-E process matters: "It doesn't make a whole lot of sense to say this process got a great result, and now we're going to match that funding but not use the process we used."

Exit Ramps Off the Roadmap

ARPA-E has always charted its own course relative to DOE's Office of Fusion Energy Sciences (FES), which recently published its Fusion Science & Technology Roadmap. Prochaska said the two offices are in regular contact and that nothing on the FES roadmap was a surprise. But ARPA-E's mandate remains distinct: by statute, the agency can't duplicate FES activities, which means it has to know what FES is doing in order to go somewhere different.

"We don't ask permission, but we also statutorily can't duplicate their activities," Prochaska said, invoking a favorite ARPA-E metaphor: "It's the analogy of the highway versus the exit ramp. We're going to go explore the exit ramps off of the roadmap."

That means pursuing high-risk enabling technologies that don't fit neatly on any official timeline. "If there's something unbelievable and unexplored, yeah, we'll go check that out. But if it's unknown just because it's not on the roadmap, we're also going to do that."

Innovating How Government Funds Fusion

Beyond technology, Prochaska signaled ambitions to rethink the mechanics of federal funding itself: expanding the use of ARPA-E's other transaction authority and speeding up how money gets to performers.

"I'm a big believer that ARPA-E shouldn't just be pursuing new technologies, but also pursuing how we fund those technologies and the administrative piece of it," he said.

What It Means

The U.S. fusion sector has grown from a handful of companies in 2014 to over 60 today. ARPA-E's new commitment is a bet that the agency's approach, small catalytic federal investments guided by empowered program directors, can keep accelerating that trajectory. With $135 million and a mandate to take risks, ARPA-E is positioned to push the boundaries of what the fusion community tackles next.