Part 2 of 2 Parts (Please read Part 1 first)
     The Century demonstration device stands about one and half tall stories tall. The liquid bismuth-lined reaction chamber inside the device is the size of a domestic water heater. The key components occupy as much space as a double-decker bus. Zap thinks its commercial-scale module, which should produce fifty megawatts of electricity, will occupy a similar volume.
     In order to stay on track to a commercial power plant, Zap needs to hit three milestones. First, it needs to be able to produce high-voltage pulses frequently and continuously. A few weeks after it was turned on this summer, Century fired one thousand and eighty consecutive pulses. So far, so good.
     The second step is to demonstrate the technology for the U.S. Department of Energy (DoE). They will run the device for more than two hours by firing at ten-second intervals to generate at least one thousand plasma pulses. In order to operate as a commercial power plant, Zap’s reactor will have to spark ten pulses per second for months on end.
     After Zap completes the Century demonstration for the DoE, the team will add more liquid bismuth to the reaction chamber. The molten metal protects other parts of the device while absorbing heat that can be used to generate electricity. Century will be able to hold over one metric ton of the liquid metal, though for now it’s starting with one hundred and fifty-four pounds.
     In the third phase, the company needs to ensure that its electrodes, the parts that generate the electric pulses, can withstand the heat and particles produced by each fusion reaction. Those parts won’t survive forever. All commercial power plants must undergo maintenance at some point. The question is primarily how frequently and for how long. Zap needs to ensure its most vulnerable parts can last long enough to make financial sense for owners of fusion power plants.
     By 2025, Zap will increase the amount of electricity that’s delivered to the reaction chamber until it hits one hundred kilowatts. Conway expects that the company will evolve the Century reactor bit by bit. He added, “Even though Century is one platform, one name, within it are multiple generations. We iterate within the iterations.”
     If Century works as expected, Conway said that “my hope would be that we’re building a demo well in this decade. If that goes well, commercial fusion power plants should follow in the early 2030s.”
     Conway acknowledges that’s a lot of “ifs”. He added that “I’m convinced that when we cut the ribbon on our first power plant and we think about the hardest problems we’ve had to solve in the last five years, my guess is plasma physics and gain is on the list. But I bet there’s a lot of other stuff on the list as well.” That “other stuff” might be what makes or breaks commercial fusion power.
     Conway continued, “Fusion needs to compete with other ways of making electricity and heat. If fusion power plants cost a lot more than other ways of making electricity, there’s not going to be many of them. There may be one that we take our kids to and show on a school field trip, and that’s it. The economics of these things is going to be really important.”

Zap Energy 

Part 1 of 2 Parts
     For fusion power researchers, hitting “breakeven” is something of a Holy Grail. It is the point at which a fusion reaction produces more power than was required to ignite it. Only one scientific experiment, at the U.S. National Ignition Facility (NIF), has accomplished that feat. It took over a decade of tweaking the system to achieve the monumental result.
     The National Ignition Facility (NIF) is a laser-based inertial confinement fusion (ICF) research device located at Lawrence Livermore National Laboratory in Livermore, California, United States. Its mission is to achieve fusion ignition with high energy gain.
     Zap Energy is constructing a seriously cheap, compact, scalable fusion energy technology with potentially the shortest path to commercially viable fusion and orders of magnitude less capital than traditional approaches. This breakthrough technology confines and compresses plasma without costly and complex magnetic coils.
     Benj Conway is the co-founder and CEO of Zap Energy. He said, “The day of the NIF result was, obviously, this incredibly celebrated scientific result. They all deserve Nobel Prizes. But you know, the day after, the question is, well, so what? What next?”
     While the NIF has managed to improve upon its first result, its device is considered to be a dead end. It was only meant to probe the limits of physics, not sell power to the grid.
     Zap’s answer, so far, is a new device it calls Century. It recently raised a one hundred and thirty million dollars Series D. After keeping the details of the Century project under wraps for several months, the startup gave reporters a peek under the hood recently. They shared exclusive details about its operation and what they hope to learn by using it.
     Zap is taking a unique approach to fusion power known as sheared-flow-stabilized Z-pinch process. Instead of using magnets or lasers to squeeze the plasma, it sends a bolt of electricity through a stream of plasma. That current generates a magnetic field that compresses the plasma and ends up creating a fusion reaction. The company has been researching the phenomenon through a series of devices at its facilities in Washington state.
     Z-pinch fusion has been around since the 1950s, but it was deemed ineffective because the plasma created fizzles out incredibly quickly. The company claims that its sheared-flow stabilization can extend the lifespan of the plasma produced almost indefinitely. This allows it to continue to generate energy for as long as needed. 
   Century is designed to simulate fusion power plant operation by firing high-voltage pulses of power every ten seconds for more than two hours. This will permit Zap to test power supplies, plasma-facing circulating liquid metal walls, and its technology to try to reduce electrode damage in the reactor.
     Conway said that Century isn’t just another physics testbed. He continued, “Our focus is not just on physics, but also on systems engineering. We’re not just a plasma physics company. We’re developing all of the key enabling technologies that we’re going to need to deliver commercial fusion. We think that doing all of this in parallel — everything all-together, all-at-once type thing — is the fastest way to actually deliver a commercial product. Century is the incarnation of that.”

National Ignition Facility