Editor’s note: This article is adapted from a 6 June post on FYI, which reports on federal science policy. Both FYI and Physics Today are published by the American Institute of Physics.
The Department of Energy’s Fusion Energy Sciences program announced last month it is soliciting proposals for projects dedicated to inertial fusion energy (IFE). For decades DOE has supported research into inducing fusion by compressing small hydrogen fuel targets, but it has done so through its nuclear weapons program. Interest in funding R&D on energy generation has compounded in the wake of Lawrence Livermore National Laboratory’s achievement last year of ignition in a laser fusion experiment.
The department expects to award a total of $45 million in grants through its solicitation, creating a series of IFE Science and Technology Innovation Hubs that will each receive between $2 million and $4 million annually over four years. DOE leaders have cautioned that it will likely take decades to determine whether IFE can be a practical power source, and its solicitation accordingly stipulates that hub proposals focus on foundational research.
The IFE initiative is part of a larger pivot the Fusion Energy Sciences program is making to pave the way for building a pilot power plant. For instance, the program is ramping up support for private fusion ventures through a new “milestone-based” funding initiative. That effort just awarded eight grants supporting concepts for a pilot fusion plant, including two IFE concepts, with the promise of larger sums as the companies receiving grants make progress. Given the direction of recent negotiations over federal spending, however, it is questionable how much money Congress will provide going forward.
A new push for fusion funding
The hubs funded through DOE’s new IFE grants will address several goals, such as deepening understanding of the physics of fuel targets and improving methods of manufacturing the targets and rapidly focusing beams on them. Other goals include improving the “scalability, modularity, survivability, compactness, and cost” of lasers and other fusion drivers and performing experiments that validate “high-gain target designs on large-scale facilities.”
The hubs are further expected to contribute to developing an IFE workforce through internships and exchange programs. Each hub proposal may include multiple institutions but will have a lead institution that must be based in the US and have "demonstrated experience” in inertial fusion methods.
DOE’s solicitation is the first in a new initiative called IFE Science and Technology Accelerated Research, or IFE-STAR, which fulfills congressional direction from the DOE Research and Innovation Act of 2018. Congress has called for DOE to spend $25 million annually on IFE while setting an appropriations target of more than $1 billion for the Fusion Energy Sciences program as a whole. This year Congress has appropriated $763 million to the program.
On top of congressional direction, the momentum behind DOE’s support of IFE was increased by the fact that the ignition milestone had been identified in a 2013 National Academies report as the optimal point at which to launch a "national, coordinated, broad-based" IFE program. DOE is committing up to $10 million to IFE this fiscal year after initially proposing only $3 million, but it is planning to keep funding relatively limited going forward, requesting $15 million for FY 2024 as part of an ask of more than $1 billion for the entire Fusion Energy Sciences program.
Congress presses for fusion technology development
Authorizing the IFE program is part of a broader change of direction that Congress has outlined for Fusion Energy Sciences. Other elements of the push include the milestone-based program, an expansion of R&D efforts in materials that would be used in fusion reactors, and support for concepts that depart from the most prevalent, tokamak-based approaches to fusion energy generation.
Among the top backers in Congress of this change of direction is House Science Committee ranking member Zoe Lofgren (D-CA), whose district is close to Livermore and who has been pressing DOE to accelerate its implementation of new fusion activities. At a recent hearing, Lofgren lauded DOE’s $1 billion request and the IFE solicitation, which Energy secretary Jennifer Granholm announced at a Livermore event celebrating the lab’s achievement in laser fusion. “I’m just wondering whether we ought to think bigger on this in terms of R&D now that we’ve got ignition,” Lofgren said.
Energy Subcommittee chair Brandon Williams (R-NY), who is new to Congress, also suggested that fusion needs more federal funding, saying, “It appears to me that the commercial partners, the private partners, seem to have been left behind in the fusion industry and have received an inadequate amount of federal funds compared to other energy sources.”
Milestone program to complement private capital
Private investment in fusion is well outstripping federal support at the moment, totaling $4.7 billion as of 2022, according to the Fusion Industry Association. DOE’s milestone-based program is the agency’s first major foray into supporting private efforts, with its initial awards totaling $46 million spread across eight companies. One of those companies, Commonwealth Fusion Systems, has already raised more than $2 billion in venture funding to build a compact tokamak that can achieve ignition before moving on to a power-generating reactor. Another award went to a US subsidiary of the British company Tokamak Energy, which, like Commonwealth, is progressing quickly with the development of a compact tokamak design.
The six other awards were granted to companies with less-developed fusion concepts, including Xcimer Energy and Focused Energy, which are pursuing IFE designs. Two awards went to stellarator concepts, which are similar to tokamaks but employ a more complicated geometry. The remaining awards support a “Z-pinch” system and a “compact magnetic mirror” approach. “By funding such a diverse portfolio, our ultimate goal is for the strongest solutions to rise to the top and to help us chart a clear path forward to bring clean fusion energy to American homes and businesses,” Granholm said in announcing the awards.
DOE has requested to ramp up its annual support for private–public fusion ventures to $135 million for FY 2024, largely to further sustain companies as they achieve new technological and programmatic milestones. Notwithstanding congressional support for fusion energy, such increases may be less likely to materialize in the wake of the recent debt ceiling negotiations, which resulted in Republicans and Democrats agreeing to keep nondefense discretionary spending essentially flat for the next two years.
