Helion Energy, a U.S.-based startup focused on generating zero-carbon electricity from fusion, has raised $500 million in a Series E funding round, with an opportunity for an extra $1.7 billion investment if the company meets certain milestones.
The funds will be used to develop Polaris, Helion’s seventh-generation fusion prototype, to be located in a facility already under construction in Everett, Wash. The generator scales performance beyond previous versions, using Helion’s pulsed, non-ignition fusion technology. Polaris is forecast to achieve net-energy generation in 2024, a milestone that could pave the way for the future development of fusion power plants.
Helion CEO David Kirtley and CTO Chris Pihl said the latest investment eliminates funding as a barrier to further development. “Transistors had not been invented yet, nor did we have high-power magnets or power electronics. However, with the advent of more advanced technology in the last 20 years or so, the main barrier has been funding. That means we can demonstrate net electricity from fusion as soon as possible,” Kirtley said.
Fusion aspires to provide a plentiful and dependable source of energy to help address expanding global energy demand. Fusion technology also addresses challenges posed by climate change. Helion and other fusion energy startups argue that renewable sources alone can’t meet growing energy.
The latest version of Polaris prototype expands on advances achieved with Helion’s sixth-generation “Trenta,” platform built in 2020. “Where Trenta is capable of running fusion pulses once every 10 minutes, Polaris will vastly increase this rate to one pulse per second,” Pihl said. Polaris is expected to generate net electricity as a byproduct of its fusion reactions in 2024, making it the first fusion generator to do so. Polaris also will demonstrate helium-3 production via a deuterium-deuterium fusion process.
Trenta completed more than 10,000 high-power fusion pulses, running continuously for more than 16 months.
Unlike traditional reactors, Helion’s reactor runs in pulsed mode without igniting a plasma. That approach simplifies reactor construction and operation, including installation in a standard container. The fusion reactor also generates electricity by induction, achieved by the interaction of a plasma magnetic field with magnets.
Helion Energy announced a global record for plasma temperatures this past summer, making it the first private fusion company to breach the 100-million°C barrier. Trenta generated 10,000 intense plasma pulses, nearly once every 10 minutes, with a length of 1 ms. Helion claims its electromagnets operate at 95-percent energy efficiency. It plans to leverage that efficiency to directly recover electricity, eliminating the need for turbines.
Fusion energy development has a checkered history, and many obstacles remain. Among them are substantiating claims of net-energy production and recycling fuel.
For example, deuterium and a helium isotope are used as fuel in Helion’s fusion system. The ideal fusion temperature is 200,000,000°C, although Helion said its process allows the system to operate at much lower temperatures. While building new generators, Helion has been able to maintain thermal capacity.
The most difficult technological challenge is recycling fuel. Helion’s process injects fuel to power a fusion reaction and generate power, then discharges the fuel, separating helium isotopes and repeating the process. Each cycle currently takes 10 minutes to complete. The goal is one cycle per second. Helion has managed to accelerate that process incrementally, but much higher speeds are needed.
“The main challenge will be increasing the pulse [repetition] rate,” said Pihl. “Our 2024 date is not a key demonstration of the science at this point.” Instead, Helion seeks to “demonstrate that fusion will be an answer to the world’s zero-carbon energy needs. After that, the goal is for Helion to commercialize electricity from fusion. There’s a huge market, and we want to be able to get this out in the world as soon as possible,” Kirtley said.