Helion Raises $425M to Build Fusion Reactor for Microsoft

Helion Secures $425 Million in Series F Funding for Fusion Reactor Development

Helion, a fusion energy startup, has garnered significant attention within the industry. The 12-year-old firm benefits from backing by Sam Altman and has established a contract to provide Microsoft with electricity, projected for 2028 – a timeline surpassing many competitors.

A Unique Approach and Recent Progress

The company’s distinctive methodology in pursuing fusion power, coupled with a degree of operational secrecy, has attracted both supporters and skeptics. However, its investor base remains confident in its potential.

Helion recently announced a $425 million Series F funding round, elevating its valuation to $5.245 billion. Furthermore, the company activated its latest prototype, Polaris, last month, anticipating it will be the first fusion reactor capable of generating electrical power.

Polaris and the Path to Commercialization

Located within a 27,000-square-foot facility in Everett, Washington, Polaris represents Helion’s seventh prototype. Its construction, completed in just over three years, is relatively swift for the fusion sector. Meeting the 2028 deadline for Microsoft, however, necessitates an accelerated pace for the development of a commercial-scale power plant.

The challenges faced by Helion mirror those encountered in other pioneering industries.

The Semiconductor Bottleneck

“The primary obstacle in AI is chip acquisition. Similarly, in fusion, the critical challenge revolves around securing the necessary chips,” explained CEO David Kirtley in a recent TechCrunch interview. “Polaris incorporates 50,000 large-scale, pulse-power semiconductors, and their procurement dictated the project’s timeline.”

The proposed solutions are aligned with this understanding. The new investment will be directed towards establishing substantial in-house specialized manufacturing capabilities. For instance, capacitors, a type of short-term energy storage device, previously required ordering three years in advance.

“Our objective is to transition from a three-year wait for capacitor delivery from suppliers to manufacturing our own, but with increased speed – aiming for production within a year or less,” Kirtley stated.

Optimism and Site Selection

Despite the complexities of building a supply chain from the ground up, Kirtley expresses optimism regarding Helion’s ability to deliver electricity to Microsoft within the projected timeframe.

“We have been actively working on site selection for the Microsoft facility for several years,” Kirtley revealed. While he refrained from disclosing a specific location, he confirmed ongoing efforts related to permitting and grid interconnection – processes that can extend over multiple years.

A Distinctive Fusion Approach

Helion’s appeal, and a source of concern for some critics, lies in its divergence from the strategies employed by most other fusion startups.

Conventional Fusion Methods

Typically, two primary approaches dominate the field. Magnetic confinement utilizes powerful magnets to compress plasma, achieving the necessary heat and density for fusion reactions, designed to operate continuously and generate steam for turbine power. Inertial confinement employs high-powered lasers to compress fuel pellets, inducing fusion. To produce sufficient heat for a steam turbine, these reactors must fire multiple times per second.

Helion’s Field-Reversed Configuration

Helion is developing a fundamentally different system, known as a field-reversed configuration reactor. Resembling an hourglass shape with a central bulge, the device is encircled by robust magnets. These magnets guide and compress the plasma during each reaction, termed a “pulse” by Helion.

Initially, a mixture of deuterium and helium-3 is injected into each end of the reactor and heated to form plasma. Magnets then mold each plasma into a doughnut shape and accelerate them towards each other at speeds exceeding 1 million miles per hour.

Upon collision within the fusion chamber – the hourglass’s bulge – the plasmas are further compressed by additional magnets. This process elevates the plasma temperature to over 100 million degrees Celsius, initiating a cascade of fusion reactions. This is analogous to the function of a spark plug in an internal combustion engine.

Energy Conversion and Efficiency

The energy released by the fusion reactions generates a surge in magnetic force, exerting pressure on the reactor’s magnets. This amplified magnetic force is then directly converted into electricity. If successful, Helion’s reactor will produce more electricity from this magnetic burst than was required to power the magnets initially. Furthermore, by harvesting electricity from magnets rather than generating steam, the system is expected to be more efficient, reducing the threshold for achieving energy breakeven.

Reactor Design and Future Potential

The current design for a commercial Helion reactor will pulse several times per second, according to Kirtley. A single reactor will generate 50 megawatts of electricity, and a power plant could incorporate multiple reactors.

The company’s laboratory systems currently achieve firing rates exceeding 100 times per second, suggesting the possibility of future reactors operating at 60 pulses per second – matching the frequency of electricity on the grid. “However, significant engineering hurdles remain to attain these high repetition rates at the substantial pulse powers involving millions of amps,” Kirtley cautioned.

Investment and Manufacturing Expansion

The new funding will accelerate work on the power plant, specifically expanding in-house machining and capacitor manufacturing capabilities. “A key factor in the Polaris timeline was the in-house fabrication of all the magnetic coils. I aim to replicate this for all components,” he explained.

Investor Details

This funding round is smaller than the startup’s previous $500 million raise. New investors include Lightspeed Venture Partners, SoftBank Vision Fund 2, and a prominent university endowment. Existing investors, including Sam Altman, Capricorn Investment Group, Mithril Capital, Dustin Moskovitz, and Nucor, also participated.