When Will We Have Nuclear Fusion Energy?

June 4. 2021. 8 mins read

One of our most popular articles so far this year was on the current state of molten salt reactors, an advanced nuclear technology that promises to be a cleaner, safer, and cheaper source of nuclear fission energy. But like so many moonshot technologies, scalability and commercial viability always seem a decade away. That’s certainly the case for nuclear fusion energy, which has long been touted as a potential source for nearly limitless, clean renewable energy. All we have to do is figure out a way to replicate and harness the energy of the sun. Believe it or not, we’re getting closer.

How Fusion Energy Works

We last checked in on the moonshot promise of fusion energy a couple of years ago. A lot has happened since then. Fusion energy companies have raised a ton of money – much more, in fact, than has been raised by molten salt reactor startups during that time. Projects have also hit a few major milestones, which we’ll get into shortly. First, let’s do a quick recap on fusion energy that even an MBA can understand.

The nuclear power plants in operation today generate energy through nuclear fission, which releases energy by splitting atoms. On the flip side, nuclear fusion creates energy by forcing together atoms that naturally carry a strong electrical repulsion. You may remember from high school science (unless you had a football coach as your physics teacher) that the sun is just a giant fusion reactor. The galaxy’s enormous fireball fuses hydrogen atoms together through extreme heat and enormous gravitational forces that overcome electrical repulsion. The process creates helium atoms and releases massive amounts of energy. 

Now we just need a way to replicate that galactic forgery here on Earth by creating a machine capable of heating gases up to 100 million degrees Celsius (C) or more (among other technical feats) and then confining that superheated plasma in a way to fuse unstable atoms of hydrogen (usually isotopes of deuterium and tritium) together to form stable helium atoms, unleashing energy with little to no nuclear waste. Thermonuclear bombs operate on the fusion principle, but no one as yet has been able to beat that sword into a plow – at least not at the level of efficiency required to make it a viable technology.

Fusion Energy Powers Up

This year could represent a major step forward to finally demonstrating that a fusion reactor can produce more energy than it consumes to operate. In fact, beginning this month, scientists plan to fire up the Joint European Torus (JET), an experiment designed to find the right mix of fuel for the International Thermonuclear Experimental Reactor (ITER) which has consumed more than $50 billion in investment dollars. Expected to come online as early as 2025, ITER would be the world’s largest tokamak, a fusion device that uses powerful magnets to corral the plasma until fusion occurs. About 35 countries are involved in the effort, including the United States, China, and the European Union. 

The ITER tokamak reactor.
The ITER tokamak reactor. Credit: ITER

Late last year, the Korea Superconducting Tokamak Advanced Research program set the new world record as it succeeded in maintaining the high-temperature plasma for 20 seconds with a temperature more than 100 million degrees C. Just this month, China announced its Experimental Advanced Superconducting Tokamak peaked at about 120 million degrees C for 100 seconds, setting yet another record. Both efforts are also collaborating with ITER.

It seems really insane that any one company would tackle the challenge of fusion energy alone, yet there are at least a couple of dozen private ventures actively pursuing the goal. In the remainder of this article, we’ll check on the progress of eight startups that are leading the pack in developing fusion energy technologies.

Most Well-Funded Fusion Energy Startup

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Pretty much every list has to begin with TAE Technologies, a California company that has raised more than $880 million since it was founded way back in 1998. It was one of three companies that we wrote about in our first article on fusion energy. The most recent venture round brought in $130 million in April from Google (GOOGL), private equity firm Vulcan Capital, and Charles Schwab (the man himself), among others. The normally tight-lipped company made headlines in April beyond announcing another round of funding. Its latest fusion reaction platform – dubbed Norman, after the company’s late co-founder – produced stable plasma at more than 50 million degrees C. The milestone is pretty significant, as the company is betting big that its advanced beam-driven Field-Reversed Configuration (FRC) technology can improve plasma confinement as things heat up.

TAE Technologies fusion energy platform.
TAE Technologies fusion energy platform. Credit: TAE Technologies

TAE Technologies will use some of its latest funds to build out its next-generation FRC platform. Copernicus, as the machine is called, will turn it up another notch, with temperatures reaching in excess of 100 million degrees C to simulate net energy production. The company is also funneling cash to commercialize its energy storage system technology for everything from electric vehicles to utility-scale electrical grid applications. It will need a way to keep the lights on until it figures out a way to keep the lights on with fusion energy.

Plasma Injector Technology

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General Fusion out of British Columbia, Canada is another fusion energy company that we’ve watched over the years. It took in a fresh round of funding back in January but didn’t offer any financial details. Total disclosed funding from more than two dozen investors (including billionaire bad boy Jeff Bezos) across the globe stands at about $192 million, but the war chest is probably much bigger than that. Founded in 2002, the company is developing a technology called Magnetized Target Fusion (MTF), a technique first developed by the U.S. Naval Research Lab in the 1970s. One key component in General Fusion’s version is the plasma injector, which sounds and looks like something out of Star Trek:

Plasma injector systems
Credit: General Fusion

The company has built and tested 24 different plasma injector systems for controlling the fuel’s temperature, density, and duration. It has conducted more than 200,000 tests to date. A new plasma injector called SLiC creates plasma within a liquid metal cavity, which captures the energy from the fusion reactor within the MTF power plant. The metal goes through a heat exchanger to produce steam, which then drives a turbine to generate electricity. The company expects to bring its fusion demonstration plant online in the next five years. Warp speed ahead!

Making the Most of Magnets

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Maybe Bezos is planning to build warp engines for his space company Blue Origin. He’s certainly covering his bases with a couple of investments by Breakthrough Energy Ventures in Commonwealth Fusion Systems (CFS). Founded in 2018 and spun off from MIT, CFS has now raised more than $200 million in funding from about two dozen investors, which also includes one of Silicon Valley’s biggest venture capital firms, Khosla Ventures. The company believes it can differentiate itself from the competition thanks to its high-temperature superconducting (HTS) magnet technology for its version of a tokamak fusion machine. As we described earlier, tokamaks use powerful magnets to confine the plasma in which fusion occurs. The HTS magnets are the largest of their kind in the world by a factor of 100 to 1000 in magnet performance, which helps shrink the size and cost of the tokamak reactor. 

The proposed tokamak from CFS.
The proposed tokamak from CFS. Credit CFS.

The company is also looking to commercialize the magnet technology for other applications, including wind turbines, MRI machines, and transportation.

Making the Most of Magnets II

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We actually wrote a deep dive into how tokamak fusion reactors work about four years ago and profiled a UK company called Tokamak Energy that had raised about $26 million at the time. Since then, the company has added another $140 million to bring total funding to about $165 million. Founded in 2009, Tokamak Energy is another academic spinout that also relies on HTS magnets made from rare-earth metal barium copper oxide. Another technological advantage, according to the company, is the spherical shape of its tokamak reactor. By moving from the standard doughnut-shaped plasma ring to an apple-shaped plasma ring, the tokamak can maintain a much higher plasma pressure for a given magnetic field. 

Hydrogen plasma in ST40 spherical tokamak.
Hydrogen plasma in ST40 spherical tokamak. Credit: Tokamak Energy

The company’s newly upgraded spherical tokamak, the ST40, is reportedly on track to hit fusion temperatures of 100 million degrees C in the coming months, which would make it the first private company to achieve that milestone if it can beat TAE Technologies.

No News is Good News?

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Another billionaire chasing fusion energy is Peter Thiel, whose investment firm Mithril Capital is among the half-dozen investors who have poured about $77 million in Helion Energy, a Seattle area startup founded in 2013. As far as we can tell, the company hasn’t been doing much since we last checked in. Even the graphics haven’t changed:

Helion Energy platform.
Credit: Helion Energy

The technology behind the Helion fusion engine somewhat resembles the FRC platform from TAE Technologies. One big difference is the choice of fuel. The latter is designed to use hydrogen-boron while the former will consume deuterium-helium-3 at much lower temperatures.

A Shot in the Dark

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Most of the fusion energy technologies we’ve discussed so far rely on some form of magnetic confinement to hold the super-heated plasma until fusion occurs. A second method called inertial confinement involves firing a projectile at a pellet of fuel so the atoms inside it are instantly heated and fused together. The fuel burns before it can blow apart, so its own mass (and therefore inertia) is effectively what confines it. This is the approach adopted by First Light Fusion, a UK company founded in 2011. The company has raised $62 million in disclosed funding, including a $25 million venture round at the end of last year. No doubt some of that money helped pay for the company’s new 55,000 pound two-stage gas gun for shooting projectiles at 20 times the speed of sound. 

55,000 pound two-stage gas gun for shooting projectiles at 20 times the speed of sound.
First Light CEO and his big gun. Credit: First Light

These hyper velocity devices are typically used by astrophysicists to simulate meteorite impacts rather than light the fusion fuse. For example, a similar gun used the International Space Station for target practice to test the panels against impacts from space debris. Fusion experimental test shots are expected to begin this month. 

Going with the Flow

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A Seattle-based startup called Zap Energy suddenly gained relevance last month after it raised a $28.5 million Series B, bringing total funding to $42.8 million. Chevron (CVX) is among the investors. Founded in 2017, the company has developed a magnetless confinement technology pioneered at the University of Washington and Lawrence Livermore National Laboratory. The technique to stabilize the plasma uses sheared flows rather than magnets. Driving electric current through the flow creates the magnetic field, which confines and compresses the plasma. The higher the current, the greater the pressure and density in the plasma. 

Zap Energy fusion device.
Credit: Zap Energy

The company claims to have achieved fusion in 2018 and is targeting breakeven energy production by 2023.

The Spheromak

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Another spinout from the University of Washington, CTFusion has raised about $3.2 million for its technology, which it calls Imposed-Dynamo Current Drive (IDCD). IDCD forms and sustains compact, magnetically confined fusion plasmas using a spheromak, as opposed to a tokamak. A spheromak arranges plasma in a shape similar to a smoke ring, which mimics astrophysical events like coronal loops on the surface of the sun. Spheromaks have been studied since the 1970s, fell out of favor, but are making something of a comeback thanks to companies like CTFusion, which was founded back in 2015.


We’re probably looking at about $2 billion in private investments between these eight companies, which still seems small compared to the international efforts underway by dozens of nations. However, the space industry, especially companies like SpaceX, has proven that innovative startups can reach the stars as well as any government-backed venture. Maybe some of these fusion energy companies will also be able to harness the power of the stars back on Earth – in about 10 years.


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  1. In this paper, it is written “The $22 billion International Thermonuclear Experimental Reactor (ITER)” :
    – This is not exact, $22bn is only the contribution of the EU to the project between 2007 and 2032.
    This is 45% of the shared costs of the projets (see:https://www.iter.org/proj/Countries ).
    So the total cost is more than $55bn , not included the decommissioning costs. Prof. Thiery PIERRE, Plasma Physics, France.

  2. Regarding Helion Energy:
    They are quiet on purpose, part of it has to do with investor relations.
    What we do know is that they have had a full scale prototype operational for at least 18 months and are working on upgrades to it’s divertor.
    See tweet here:
    They are also hiring A LOT.

    Another company pursuing the Z- Pinch is MIFTI. They are using a different technique to make it viable (Staged Z- Pinch) and are aiming for break even experiments in the next 18 months. They have funding from US Nuclear, if I am not mistaken.

    1. Thank you for the comment Elmar. There’s no way we can monitor all the social media accounts of companies we write about so if they have something to say, it needs to be in a press release on their site. (No public relations people, we don’t need you to send us press releases thank you). Thank you for the additional name as well and for taking the time to comment. We learn a lot from people who comment such as yourself.

  3. Forgot to add another thing about Helion Energy.
    Their reactor design differs from TAE’s in several aspects.
    The biggest is that Helion’s design is pulsed, while TAE’s is steady state.
    Both merge FRCs, but Helion also accelerates the FRCs to high speeds and magnetically compresses them at the same time to greatly increase the density and temperature within a very short time to achieve fusion. The fusion products are mostly charged particles that then rapidly expand which induces a current in the compression and acceleration magnets. This means that they do not require expensive and complicated steam plants, which lowers the cost of deployment (among other benefits).
    The pulsed nature of their reactor also allows them to extract and separate fusion products and “unburned” fuel between pulses. That is another big advantage of their design.
    I am sure I am forgetting a few things, but these are the ones that come to my mind right now.

    1. Thank you for this additional color. This technology can become very complex, very quickly, so appreciate your explanation.

  4. Science is looking for quark plasma, not fusion. Fusion is part of the conversation of energy. Once quark plasma is started, it is the dark matter of space that continues the reaction. The dark matter of space can go through any normal matter to attack the reaction. Once it is started, it will require no energy input at all, only containment of the energy. It is quark plasma that makes our universe live indefinitely, not fusion. Black holes are made of this plasma. Eventually, they create light when the quarks form neutrons on the surface.

    1. It’s this sort of hardcore comment that makes us nod our heads and pretend like we understand what’s being explained. Thank you for taking the time to comment! We always enjoy reading all the interesting comments that inevitably follow a piece like this one.

  5. I think the author should add also more companies in this list like LPPfusion, Pulsar Fusion, Renaissance Fusion and etc.

    1. This is always tricky Dr. because if you claim to have an exhaustive list, you’ll always have someone saying “you missed us!” More importantly, people won’t engage the same if you publish a 4,000-word piece documenting every single player in the space. What we’ve done here is try and look at who might be closest to making fusion a reality. We’ll note the names you’ve listed and thank you for taking the time to comment!

  6. November 5, 2021 : Helion secures $2.2B to commercialize fusion energy – a $0.5 billion Series E, with an additional $1.7 billion of commitments tied to specific milestones. The round was led by Sam Altman, CEO of OpenAI and former president of Y Combinator. Existing investors, including co-founder of Facebook Dustin Moskovitz, Peter Thiel’s Mithril Capital and notable sustainable tech investor Capricorn Investment Group.

  7. I would add to the list: “First Light Fusion Limited”. I came acrosss it as it is no 2 position in IP Group portfolio – position worth £114.5M.
    IP Group plc, which develops world-changing science and technology businesses across life sciences, technology and cleantech, notes that portfolio company First Light Fusion Ltd (“First Light” or “the Company”) has confirmed that it has achieved fusion which has been independently validated by the UK Atomic Energy Authority (UKAEA).
    This is the first time fusion has been achieved using a projectile-based approach, harnessing the unique target technology developed by First Light. Projectile fusion is a new approach to inertial confinement fusion that is simpler, more energy efficient, and has lower physics risk. First Light has achieved fusion having spent less than £45m, and with a rate of performance improvement faster than any other fusion scheme in history.
    IP Group believes achieving this world-first will at least result in an initial doubling of the value of the Company with recent comparatives and third party valuation work suggesting a doubling to quadrupling may be achieved at the next funding round.
    Our preliminary assessment, based upon the lower end of the range, implies a carrying value of the asset that will generate an initial net fair value gain of at least £57m (or approximately 5 pence per share). As at December 31 2021, IP Group’s undiluted beneficial holding of 27.4% in First Light was valued at £57.3m.

    1. We do an updated list about every several years after which time we always report what everyone knew already – fusion is 5-10 years away 😉

      Thank you for the heads up and we’ll note this name for our next fusion update!

  8. See YT video at Real Engineering channel: “A New Way to Achieve Nuclear Fusion: Helion”.
    It explains in great details how Helion’s idea works. Very impressive. I like everything about it.