A process similar to the one that powers the sun is used to produce fusion energy. Instead of splitting the atom, as nuclear fission does, atoms are pushed together, the ‘fusion’ part, and it runs on hydrogen extracted from the sea, making that the easy bit. A lot of energy is required to kickstart the reaction though, and magnetic fields that pack plenty of power are needed to contain the plasma: its charged state.
It will be several years before this technology is able to supply electricity to the public, though a breakthrough announced today by MIT researchers, and partner startup company Commonwealth Fusion Systems(CFS), might speed things up when it comes to making magnets powerful enough to hold the plasma. After three years of research and design the MIT team has been able to successfully trial the most powerful magnet of its type ‘ever created on earth’.
“Fusion in a lot of ways is the ultimate clean energy source,” said Maria Zuber, MIT’s vice president for research and E. A. Griswold Professor of Geophysics. “The amount of power that is available is really game-changing. The fuel used to create fusion energy comes from water, and the Earth is full of water — it’s a nearly unlimited resource. We just have to figure out how to utilise it.”
Overcoming the technological hurdles posed by the need to develop extraordinarily strong magnets, puts the MIT-CFS collaboration ‘on track to build the world’s first fusion device that can create and confine a plasma that produces more energy than it consumes’. The demonstration device – called SPARC – that will prove it is due to be ready by 2025.
“The challenges of making fusion happen are both technical and scientific,” explained Dennis Whyte, director of MIT’s Plasma Science and Fusion Center, which is working with CFS to develop SPARC. “But once the technology is proven it’s an inexhaustible, carbon-free source of energy that you can deploy anywhere and at any time. It’s really a fundamentally new energy source.”
“None of us are trying to win trophies at this point. We’re trying to keep the planet liveable.”
There is still much work to be done but the potential of SPARC is exciting those working on it.
Zuber said: “I now am genuinely optimistic that SPARC can achieve net positive energy, based on the demonstrated performance of the magnets. The next step is to scale up, to build an actual power plant. There are still many challenges ahead, not the least of which is developing a design that allows for reliable, sustained operation. And realising that the goal here is commercialisation, another major challenge will be economic. How do you design these power plants so it will be cost effective to build and deploy them?”
The scientists behind the innovation envision a future with ‘thousands of fusion plants powering clean electric grids around the world’.
Zuber added that when that day arrives ‘we’re going to look back and think about how we got there, and I think the demonstration of the magnet technology, for me, is the time when I believed that, wow, we can really do this’.
Nuclear fusion took another step forward last month when America’s National Ignition Facility (ANIF) announced it had successfully used laser technology to trigger a reaction in a tiny pellet shaped target containing hydrogen. An outcome, which was achieved through a process called inertial confinement fusion (ICF), that puts the world on the ‘threshold of fusion ignition’ the scientists at the facility said.
“It is a testament to the innovation, ingenuity, commitment, and grit of this team and the many researchers in this field over the decades who have steadfastly pursued this goal,” LLNL Director Kim Budil was quoted as saying on the ANIF website.
Further experiments are now underway to further develop the laser technology.
There is no getting away from the fact that nuclear power in any form is unlikely to win many popularity contests. The Fukushima disaster and Chernobyl are etched into the consciousness, but with global grand challenges as far as the eye can see, it would be dangerous to cancel potential solutions before they are given a fair hearing. Especially as engineers and scientists have been busy exploring innovative ways to prevent some of the causes of these previous tragedies.
Talking about the development of future nuclear facilities in his recent book, Bill Gates said that the design proposed for its fission reactor by TerraPower, a company he is founder and chairman of, would mean ‘accidents would literally be prevented by the laws of physics’.
“The design would be inherently safe, using some ingenious features to control the nuclear reaction,” he wrote. “For example, the radioactive fuel is contained in pins that expand if they get too hot, which slows the nuclear reaction down and prevents overheating.”
Despite recent advances though, there is a long way to go before it will even be possible for fusion power to be a source supplying electricity to homes but with every new milestone the challenge may well turn more to effectively communicating the implications and progress of new nuclear.
“What’s most important is that the world gets serious once again about advancing the field of nuclear energy. It’s just too promising to ignore.”