Nuclear Fusion Startup Zap Energy Makes Progress and Gets $160 Million

Zap Energy creating the first plasmas in their FuZE-Q prototype. They achieved Q=1 where the process of nuclear fusion inside a plasma yields more energy than was consumed to create the plasma.

In 2021, Zap Energy used sheared-flow stabilization to extend the lifetime of Z-pinch plasmas at 500 kiloamps (kA) of current. Zap’s sheared-flow-stabilized Z-pinch technology might be a fast path to commercially viable fusion. It requires orders of magnitude less capital than traditional approaches. Zap Energy has over 60 employees based in Seattle, Everett and Mukilteo, Washington.

Following a $27.5 million Series B in May 2021, Zap Energy’s oversubscribed $160 million Series C funding round was led by Lowercarbon Capital with participation by a new set of investors that includes Breakthrough Energy Ventures, Shell Ventures, DCVC and Valor Equity Partners. Existing financial and strategic investors who have backed the new raise include Addition, Energy Impact Partners (EIP) and Chevron Technology Ventures.

Zap Energy’s technology does not require any superconducting magnets or high-powered lasers.

The conceptual basis for the technology was developed at the University of Washington (UW) together with collaborators from Lawrence Livermore National Laboratory. UW professors Uri Shumlak and Brian A. Nelson teamed up with entrepreneur and investor Benj Conway to co-found Zap Energy in 2017 to accelerate and ultimately commercialize the research.

FuZE-Q is the fourth generation of Z-pinch device that Zap Energy has built.

AIP – Physics of Plasmas – Thermonuclear neutron emission from a sheared-flow stabilized Z-pinch

The fusion Z-pinch experiment (FuZE) is a sheared-flow stabilized Z-pinch designed to study the effects of flow stabilization on deuterium plasmas with densities and temperatures high enough to drive nuclear fusion reactions. Results from FuZE show high pinch currents and neutron emission durations thousands of times longer than instability growth times. While these results are consistent with thermonuclear neutron emission, energetically resolved neutron measurements are a stronger constraint on the origin of the fusion production. This stems from the strong anisotropy in energy created in beam-target fusion, compared to the relatively isotropic emission in thermonuclear fusion. In dense Z-pinch plasmas, a potential and undesirable cause of beam-target fusion reactions is the presence of fast-growing, “sausage” instabilities. This work introduces a new method for characterizing beam instabilities by recording individual neutron interactions in plastic scintillator detectors positioned at two different angles around the device chamber. Histograms of the pulse-integral spectra from the two locations are compared using detailed Monte Carlo simulations. These models infer the deuteron beam energy based on differences in the measured neutron spectra at the two angles, thereby discriminating beam-target from thermonuclear production. An analysis of neutron emission profiles from FuZE precludes the presence of deuteron beams with energies greater than 4.65 keV with a statistical uncertainty of 4.15 keV and a systematic uncertainty of 0.53 keV. This analysis demonstrates that axial, beam-target fusion reactions are not the dominant source of neutron emission from FuZE. These data are promising for scaling FuZE up to fusion reactor conditions.

SOURCES- Zap Energy, AIP Physics of Plasma
Written by Brian Wang,

12 thoughts on “Nuclear Fusion Startup Zap Energy Makes Progress and Gets $160 Million”

  1. It’s a pity this approach cannot be combined with Helions method of extracting energy through the expanding cloud of charged particles pushing on the magnetic field.
    Since this fusion reactor uses steam and turbines just like a tokamak reactor, it would need to reach similar Q-values as them to reach commercial viability. That is, a Q>200. This is not easy.

    The Helion approach requires far lower Q-values due to it’s energy extraction method..

    • Is there a specific reason they can’t use the same approach as Helion or is it just intellectual property issues? I agree that if you combine the two innovations it would be the obvious winner.

      • So far at least, Zap is just attempting D-T fusion, where 80% of the energy is released as neutron radiation, requiring a turbine. Helion’s approach is only possible with some form of aneutronic fusion, where the energy is released mostly as fast-moving charged particles. They’re using a combination of D-He3 (aneutronic) and D-D (to make the He3), releasing only 6% of energy as neutron radiation.

  2. So, they pump a liquid metal over the “edge” so that it runs down the central core of the fusion chamber, right?

    But if liquid metal is a prerequisite for absorbing neutrons, should there not be liquid above the central shaft? Why should there be no neutron flux upwards?

    So if some parts of the chamber (top parts) can survive the neutron flux without resorting to liquid metals, would it not make sense to skip the liquid metal altogether? They will be forced to change some parts of the chamber as it gets brittle or when it becomes radioactive, so why not just change the whole chamber and not have to worry about plasma contamination by the metal vapor pressure?

    • I believe that the liquid metal is meant to absorb neutron energy and to convert it to thermal energy to spin a turbine. The metal isn’t neutron protection so much as it is for energy collection.

    • These guys are doing Z pinch fusion. You run a current through a plasma, and self-interactions cause it to pinch down to fusion density and temperature. That’s why sparks look like lines, not fat tubes…

      But Z pinches are unstable, they’re non-linear, so they tend to pinch and bulge.

      They’re using shear stabilization to counter that: The plasma is flowing through the pinch, and some parts of the plasma are moving faster than other parts, so the instabilities get averaged out along the length of the pinch.

      LLP goes in the opposite direction, they USE the instabilities to cause a kink in the discharge where energy gets concentrated, and the fusion happens in really exotic conditions, ultra-high temperature and density.

      This Z pinch approach isn’t just easy to pull off, (I think it was the original approach to fusion reactors, decades ago, before they discovered instabilities.) it’s also very well suited to exploiting for fusion rocket engines. So if they get this working, you’ll have nuclear rockets for use in space shortly afterwards.

      • Neat to see another commercial approach using pinches.

        Plasma purity can be an issue, not sure how they will address that with all the molten metal lining the chamber. Much of LPP’s grief has been tied to high Z impurities in the filaments, which is also why they have transitioned to a plasma with a record low level of impurities.

        Side note: LPP has mentioned on their Facebook account that once they get their switches firing correctly that they are willing to take a diversion from p-B fusion and do some D-T pinches.

        • Realistically, the chances of achieving engineering breakeven with D-T fusion are enormously better than with P-B fusion. If they got even that working they’d be flooded with money.

          • “If they got even that working they’d be flooded with money.”

            I think that is what is motivating their thinking. If they had Q near 1 then they could raise their valuation by 20x and raise money.

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