In Lower Hutt, a half-tonne magnet levitates - a key step toward an era of clean, super-abundant nuclear fusion energy
A Kiwi, Sir Ernest Rutherford, split the atom on the smell of an oily rag, in 1908.
In a warehouse in light industrial Lower Hutt, OpenStar is working towards a breakthrough that would arguably be of even greater significance, building on Rutherford’s later work on fusing atoms - a process that holds the promise of cheap, clean and abundant energy.
Late yesterday, Prime Minister Christopher Luxon hit a big green button to trigger the final stage for OpenStar’s first reactor, “Junior”, to levitate a 550kg superconducting magnet in 40 square metre cloud of superhot plasma for around 20 seconds as a “lifter” electromagnet at the top of the chamber counteracted gravity.
It was the first public demonstration of OpenStar’s technology and was billed as a crucial step on the path to producing “virtually limitless power” through fusion.
Nuclear fission – used by today’s nuclear reactors – smashes atoms apart, producing radioactive waste. Nuclear fusion works by replicating the process that stars use to generate energy. At the star’s core, conditions of high temperature and pressure force nuclei of lighter atoms to fuse into larger atoms and release tremendous amounts of energy without any carbon emission or radioactive waste.
“Junior” is designed to produce plasma at temperatures close to one million degrees centigrade.
A series of four reactors is envisaged as OpenStar builds up to support 100m centigrade plasma – the temperature needed for fusion, a process that involves taking two light atomic nuclei, usually isotopes of hydrogen called deuterium and tritium, and forcing them together to form a heavier helium nucleus. The process releases a high-energy neutron and “staggering amounts of energy”.
All going well, its successor, Tahi - which is still on the drawing board -will produce plasma at around 11 million degrees in around two and a half years. Tahi will be the same dimensions as Junior, and do the same things, just more efficiently on every level.
And the envisaged third reactor, Maui, will produce plasma at 100 million degrees - the point where OpenStar founder Dr Ratu Mataira says fusion can potentially become economic. Some proponents see it producing power at a quarter of the cost per megawatt hour of today’s fission plants.
Maui could be online by 2031.
Mataira says while Maui might not be making commercial power, the neutrons it would produce would still be very valuable. OpenStar could sell isotopes for medical science - a market potentially worth several hundred million dollars per year.
The fourth reactor, Tama-nui, is seen as being the first to supply power to the national grid. It could potentially be online in 2030s.
When could we see nuclear fusion?
OpenStar’s chief science officer, Dr Darren Garnier, says he thinks nuclear fusion will be cracked in the 2030s, with the first fusion power plants in the 2040s.
Junior was built, tested and reached the internationally recognised milestone of “first plasma” within two years for less than US$10m ($16.5m), demonstrating a comparatively fast and cost-efficient approach to fusion, Garnier says.
Various players in Europe have already achieved fusion, but only fleetingly - sometimes only for milliseconds.
US firm Helion, for example, briefly achieved 150m degrees centigrade this month with its seventh-generation Polaris reactor.
Mataira’s reaction: “There’s science and then there’s engineering. You’ve got to put less energy in than you get out.” Helion and other rivals are some distance, he says, though he also stresses the cooperative nature of the industry, often pointing out that the “open” in OpenStar is a reference to collaboration.
What will it cost?
OpenStar has raised around US$18m in venture capital so far, Mataira says.
Earlier this month, it received a $35m loan through the Government’s Regional Infrastructure Fund, driven by Regional Development Minister Shane Jones (who was also on-hand for the demo).
“That is the absolute bare minimum to build Tahi, and the government funding is critical to making sure that happens in New Zealand,” Mataira says.
The money will be used to triple staff numbers from 70 today. Garnier - an American who splits his time between Boston and Wellington - says most will be in NZ, but some will be in the US.
‘West Coast money’
For the medium term, OpenStar wants to raise US$120m to US$150m. Mataira says the Government’s $35m forms part of that total.
“The fundraising process is underway at the moment,” he says.
OpenStar’s investors so far include Auckland-based Icehouse Ventures - which holds a 25% stake, the largest outside of Mataira’s 54% - Australia’s largest VC fund, Blackbird, the Crown via NZ Growth Capital Partners’ Aspire Seed Fund (2%) and Outset Ventures, which numbers Sir Peter Beck on its investment committee (0.8%)
Mataira says the startup will have to look beyond Australasia to hit its US120m to US$150m target.
“The reality of the world is that that kind of capital exists on the west coast of the United States. And it’s not just about the amount of money. It’s also about the types of opportunities that money is willing to chase and bet on.”
In October last year, Mataira (Ngāti Porou, Ngāti Kahungunu and the grandson of the late Dame Kāterina Te Heikōkō Mataira, credited with sparking a te reo Māori renaissance in the 1970s) backed a roadshow that sought to raise $8.5m for OpenStar from iwi investors. There was no immediate success, but Mataira says he’s still hopeful in the medium term. He sees “deep tech” investments as a point of diversification for tribes who have traditionally focused on primary industries and property.
(OpenStar already has one iwi investor onboard: Ngāi Tahu New Economy, which holds a 0.41% stake.)
Other efforts
Private and Government-funded fusion start-ups and projects in the US, Japan, Korea and Europe often measure their funding in the billions. The EU allocated €5.61b ($11b) for its ITER fusion project for 2021 to 2027 for example.
But none have achieved “power positive” fusion - outputting more power than it takes to obtain their plasma.
Matairi says the “levitating dipole” technology he’s helped pioneer from his PhD at Victoria University’s Robinson Research Institute onwards (building on the work of Garnier and others with MIT and Columbia’s LDX project between 1998 and 2014 and the late Dr Akira Hasegawa who proposed the dipole - or a magnet floating in mid-year between two charges - in 1987 while at Bell Labs in New Jersey) is far more cost-efficient than the huge “tokamak” designs favoured by most fusion contenders offshore, where the plasma is surrounded by a non-levitating fixed magnet in a donut shape.
Junior is a noisy beast pic.twitter.com/mirSoPDRKK
— Chris Keall (@ChrisKeall) February 17, 2026
Junior used the equivalent of 20 microwaves’ worth of power for yesterday’s demo. A superconducting circuit, operating in a vacuum with a billionth of an atmosphere, acted as a wireless charger for minimum energy loss.
Mataira sees networks of “hundreds of thousands” of fusion plants.
Luxon told the audience the demonstration was “very much a glimpse of what New Zealand can become if we back ourselves in advanced technology”.
“Access to abundant energy has determined which nations lead and which ones fall behind.
“Energy powers industry. It drives productivity. It lifts living standards, and in a world that is increasingly competitive and reliant on AI, it underpins both prosperity and also our security. So we need as much safe, reliable and affordable energy as we can possibly get.”
Large-scale fusion power is Mataira’s aim, but he also stresses that the Government’s $35m will help create a local fusion industry. For example, key components of Junior were built by Palmerston North firm E-Tech.
“We need to start exporting technology, not people,” Mataira says.
Chris Keall is an Auckland-based member of the Herald’s business team. He joined the Herald in 2018 and is the technology editor and a senior business writer.