DARPA Bets on Startup to Solve Fusion's Biggest Electricity Gap
Avalanche Energy secures a $5.2M DARPA contract to develop radiovoltaics, aiming to turn fusion radiation directly into electricity for military and space use.
A New Approach to Harvesting Energy
In the world of nuclear science, the "fusion contradiction" remains a defining hurdle: while initiating a fusion reaction is relatively straightforward (even a dedicated hobbyist can build a fusion device at home) efficiently extracting electricity from that reaction is not.
While current experimental fusion reactors can produce power, the industry is struggling to convert that power into usable electricity. Most traditional methods rely on heating water to drive steam turbines, a process that loses nearly 40% of the energy produced. Seattle-based startup Avalanche Energy is looking to bypass this inefficiency through the development of radiovoltaics.
Boosting Efficiency with Radiovoltaics
Radiovoltaics function similarly to the photovoltaic cells found in solar panels. However, instead of harvesting light, they use semiconductors to convert radiation directly into electricity. While the technology has existed for years, it has been plagued by two major flaws: low output and the tendency for the radiation itself to degrade the semiconductor material over time.
Avalanche Energy aims to solve these issues. On Tuesday, the company announced it has been awarded a $5.2 million contract from DARPA (the Defense Advanced Research Projects Agency) to develop high-durability radiovoltaics.
While current experimental fusion reactors can produce power, the industry is struggling to convert that power into usable electricity.
Beyond the Reactor: Military and Space Applications
The Pentagon is particularly interested in how these materials could revolutionize nuclear batteries. By using the radioactive decay of elements like polonium, DARPA hopes to create a new class of long-lasting power sources for:
- Spacecraft and Satellites: Providing reliable energy for years in orbit.
- Autonomous Systems: Powering drones or sensors in remote environments where traditional logistics and refueling are impossible.
For Avalanche, the DARPA project serves a dual purpose. Both nuclear batteries and fusion reactions produce alpha particles (high-energy radiation that can damage reactor walls. By developing a "sheathing" of radiovoltaic material, Avalanche hopes to protect its hardware while simultaneously capturing alpha particles to boost electrical output.
The Race for "Q>1"
The ultimate goal for fusion startups is "breakeven," or Q>1) the point where the energy generated by the reaction exceeds the energy required to sustain it. By effectively putting alpha particles to work, Avalanche could reach commercial viability much faster.
In addition to the DARPA contract, Avalanche has secured $1.25 million from AFWERX, the U.S. Air Force’s research lab, to utilize advanced computational modeling for rapid material discovery.
As the fusion sector matures, Avalanche’s success could see it move beyond reactor development to become a key component supplier for the wider industry. "A fusion reactor that makes electricity is better," says Daniel Velásquez, materials science lead at Avalanche. With the backing of the U.S. military, the company is betting that radiovoltaics are the missing link to making that a reality.
