By Laura Paddison, CNN
OpenStar Technologies' nuclear fusion reactor in Wellington. Photo: OpenStar Technologies
In a commercial warehouse overlooking the ocean in Wellington, a startup is trying to recreate the power of a star on Earth using an unconventional "inside out" reactor with a powerful levitating magnet at its core.
Its aim is to produce nuclear fusion, a near-limitless form of clean energy generated by the exact opposite reaction the world's current nuclear energy is based on - instead of splitting atoms, nuclear fusion sets out to fuse them together, resulting in a powerful burst of energy that can be achieved using the most abundant element in the universe: hydrogen.
Earlier this month, OpenStar Technologies announced it had managed to create superheated plasma at temperatures of around 300,000C - one necessary step on a long path toward producing fusion energy.
The company hailed it as a breakthrough. "First plasma is a really important moment," said Ratu Mataira, OpenStar's founder and CEO, it's "the moment that you know that everything works effectively".
It took the company two years and around US$10 million (NZ$17m) to get here, he told CNN, making it cheap and fast compared to many of the decades-long, government-led efforts that have dominated the fusion energy space.
OpenStar is one of a number of startups pushing the world toward the nuclear fusion finish line by seeking ways to commercialize the futuristic power source, even before it's even been proved viable.
They come with big promises and wads of investment - fusion companies have attracted more than $7.1 billion in funding, according to the Fusion Industry Association. But experts warn there's still a long, complex road ahead of them.
Fusion - the same process that makes the sun and other stars shine - is often called the holy grail of clean energy: it's near limitless, produces no planet-heating pollution and doesn't have the long-term radioactive waste problem that plagues fission, the nuclear technology the world currently uses.
An illustration of the inside of OpenStar Technologies' "levitated dipole" nuclear fusion reactor. Photo: OpenStar Technologies
It's a moonshot for tackling the escalating climate crisis. A baseload power able to use existing grid infrastructure, it offers what people want: a climate solution that involves little change to the world as it is now.
But recreating it on Earth has proved fiendishly tricky.
The most popular technology involves a donut-shaped machine called a tokamak, which is fed with two forms of hydrogen gas - deuterium, found in seawater, and tritium extracted from lithium.
The temperature inside the tokamak reaches 150 million degrees (C), 10 times hotter than the sun's core. Under this extraordinary heat, the hydrogen isotopes smash together within a plasma, causing them to fuse in a process creating enormous amounts of energy.
Strong magnetic coils in the tokamak confine the plasma, a task scientists describe as like holding Jell-O together using rubber bands.
OpenStar's technology flips this on its head, essentially turning the tokamak inside out. Instead of having plasma inside magnets, it has a magnet inside the plasma.
Its reactor features a single, extremely powerful magnet levitating inside a vacuum chamber about 16 feet (five metres) wide, which looks like a steel donut on legs. The design is modelled after the plasma in planetary magnetic fields, including Earth's.
The physicist Akira Hasegawa came up with the concept in the 1980s, based on his study of plasma around Jupiter. The first machine using these principles was built at MIT, in collaboration with Columbia University, and turned on in 2004. But it closed in 2011.
"It wasn't going to scale with the technology that they had," Mataira said. By swapping out some of this technology and using newer types of magnets, OpenStar says they have cracked the problem.
The advantage of this reactor is it's easier and faster to engineer than a tokamak, Mataira said. This "allows you to rapidly iterate and improve performance very, very quickly." It's also less complex than a tokamak - which he compares to "building a ship in a bottle" - meaning it's much faster to fix if something goes wrong.
The fusion reactor looks like a steel donut on legs and is housed in a warehouse in Wellington, New Zealand. Photo: OpenStar Technologies
OpenStar, which has already raised US$12 million (NZ20.2m) and is now embarking on a much bigger funding round, plans to build two further prototypes over the two to four years, to work out how to scale it and make it viable.
OpenStar is one of a constellation of fusion companies has sprung up over the past five years, pursuing diverse technologies, said Gerald Navratil, a professor of fusion energy and plasma physics at Columbia University.
"The maturity of the field is such that now private venture capitalists are willing to put up money to try to see if they can get to fusion a little faster," he told CNN.
One of the largest commercial ventures, Commonwealth Fusion Systems, which uses high-temperature superconducting magnets within a tokamak, has raised more than US$2 billion (NZ$3.4b).
Others, like OpenStar, are exploring more unusual tech. Seattle-based Zap Energy is trying to build a compact, scalable reactor that doesn't use magnets at all, but instead fires pulses of power into a stream of plasma.
The billion dollar question is still: when will fusion power be ready? OpenStar says six years. Commonwealth Fusion says it can deliver fusion power to the grid in the early 2030s. Zap Energy foresees a similar timeframe.
Other players are more cautious. The UK Atomic Energy Authority, a government body developing fusion, said fusion isn't likely to become a commercial reality until the latter half of this century due to the significant scientific and engineering challenges.
Sometimes startups "tend to be a little aggressive in what they're promising," Navratil said. There's a big difference between producing energy from fusion and having a practical system that puts power on the grid and is safe, licensed and operating, he added.
Mataira remains buoyant and confident in the ability of agile startups to push the world further and faster toward a tantalising clean power, which for decades has seemed just out of reach.
"Not all of the fusion companies will be successful, OpenStar might be one of those," he said, "but we as a society will learn faster."
-CNN
