Helion Energy

Helion Energy is a fusion power company aiming to build the world's first fusion power plant. Helion's approach utilizes a pulsed non-ignition fusion system called a plasma accelerator that directly recovers electricity rather than using heat to create steam and turn a turbine. The system uses deuterium and helium-3 (D-³He) as fuel, with the helium-3 produced by fusing deuterium in its plasma accelerator via a patented closed-fuel cycle. Helion's accomplishments include the following:

• Becoming the first private company to reach fusion-relevant plasma conditions of 9+ keV ions (100M ^oC)
• Demonstrating magnetic energy recovery with 95% efficiency
• Exhibiting compression fields greater than 10 Tesla
• Sustaining plasma with lifetimes greater than 1ms

Helion plans to start producing and selling electricity from its first fusion power plant by 2028, dramatically shortening the timeline for commercially viable fusion energy. In May 2023, Helion announced an agreement to provide Microsoft electricity from the company's first fusion power plant. The deal marks the first time a fusion company has signed a deal to sell electricity. As part of the agreement, energy company Constellation will serve as the power marketer, managing transmission for the project. The plant is expected to go online by 2028 with a target power generation of 50MW or greater after a one-year ramp-up period.

While the idea for Helion started in 2010, the company was officially founded in 2013 by four scientists working at MSNW, a company spun off from the University of Washington working on plasma physics for aerospace and power generation purposes. The founders of Helion are David Kirtley (CEO), Chris Pihl (CTO), George Votroubek (Director of Research), and John Slough (founder of MSNW). In November 2021, Helion announced a $500 million Series E round with an additional $1.7 billion of commitments tied to specific milestones. The round was led by Sam Altman (CEO of OpenAI), with participation from previous investors in the company Dustin Moskovitz, Peter Thiel’s Mithril Capital, and Capricorn Investment Group. Altman has been involved with Helion since 2015 as an investor and chairman.

The idea behind Helion's technology dates back to the 1950s and the three-stage Toy Top device developed by Dr. Coensgen at the University of California Radiation Lab (UCRL). The device compresses plasma in three staged chambers producing a high-density, high-temperature plasma achieving ion energies several hundred times higher than their initial value.

Most prototypes for fusion electricity generation combine deuterium (hydrogen-2) and Tritium (hydrogen-3), releasing energy in the form of neutrons (accounting for 80% of energy production). The heat that results from the fusion reaction is then used to produce steam that powers a turbine. Helion's technology takes an aneutronic approach to fusion, combining deuterium (hydrogen-2) and helion (helium-3) to produce helium-4 (the common isotope of He) and a single proton. This reaction releases energy without creating radioactive byproducts. The proton's momentum interacts with the reactors containing magnetic field directly generating electricity with projected efficiencies of 85-95%.

Representation of Helion's Plasma Accelerator design.

Helion's plasma accelerator creates two separate plasmas at opposite ends of the 40-foot prototype. This is done by heating deuterium and helium-3 to plasma conditions and using magnets to confine the plasma in a field reversed configuration (FRC), a shape similar to a donut or torus. Magnets then accelerate the two FRCs to one million miles per hour, colliding at the center of the device. At the point of collision, the resulting plasma is further compressed using powerful magnets, reaching a fusion temperature of 100 million degrees Celsius. At this temperature, the deuterium and helium-3 ions are moving fast enough to achieve fusion, releasing more energy than is consumed. As the new fusion energy is generated, the plasma expands, pushing back against the magnetic field. As described by Faraday's law, the change in field induces a current which directly recaptured as electricity.

Helion has built six prototypes and is expecting to complete the seventh in 2024. The sixth prototype, named Trenta, was completed in 2020 and ran until 2022 creating fusion reactions almost every day. It completed almost 10,000 high-power pulses and operated under a vacuum for sixteen months. Trenta became the first private organization to reach plasma temperatures of 100 million degrees Celsius (9 keV), the temperature at which large amounts of fusion start to occur, enough to generate commercial electricity.

Helion's sixth prototype Trenta.

Helion's seventh fusion prototype, Polaris, will demonstrate the production of electricity from fusion and will also demonstrate helium-3 production through deuterium-deuterium fusion. The construction of Polaris will also show how to scale up technology from previous prototypes to commercial levels. While Trenta ran fusion pulses once every ten minutes, Polaris aims to achieve a higher repetition rate during continuous operations.

In comparison to the Tokamak fusion reactor ITER in France, which cost over $50 billion, Helion Energy's reactors are significantly smaller and are estimated to cost in the low tens of millions. Helion CEO David Kirtley has stated these reactors should produce 50 MW of electricity, enough to power ~40,000 US homes.