American scientists at the National Ignition Facility (NIF) in California made a giant leap in the quest for net energy gain with a major nuclear fusion breakthrough.
The US has finally unleashed an infinite source of clean energy that could help end dependence on fossil fuels. Scientists achieved more energy out of a nuclear fusion reaction than they put in.
The NIF had been pursuing nuclear fusion for more than a decade and it struggled to meet its goal. But that changed on the night of December 5 when researchers used laser beams to zap a tiny pellet of hydrogen fuel. The energy produced exceeded the energy the lasers put in.
The energy produced could one day provide clean, safe electricity without greenhouse gas emissions.
What is Nuclear Fusion?
According to the International Atomic Energy Agency (IAEA), nuclear fusion is the process by which two atomic nuclei combine to form a single heavier one while releasing massive amounts of energy. Fusion reaction occurs when in a state of matter called plasma, which is a hot charged gas made of positive ions and free-moving electrons with unique properties distinct from solids, liquids or gasses. In other words, it involves smashing together light elements such as hydrogen to form heavier elements, releasing a huge burst of energy in the process. This gives rise to the heat and light of the sun and other stars.
Dr Robbie Scott, of the Science and Technology Facilities Council's (STFC) Central Laser Facility (CLF) Plasma Physics Group, believes fusion can potentially provide a near limitless safe, clean, source of carbon-free baseload energy. "This seminal result from the National Ignition Facility is the first laboratory demonstration of fusion energy-gain where more fusion energy is output than input by the laser beams." Scott says the scale of this breakthrough for laser fusion research cannot be overstated.
He explained the experiment shows unambiguously that the physics of Laser Fusion works. "In order to transform NIF's result into power production, a lot of work remains but this is a key step along the path."
Challenges Remain
While the major breakthrough and milestone is celebrated, the dream of harnessing this energy and using it remains many decades away. Tony Roulstone, a nuclear engineer at Cambridge University in the UK, believes fusion is unlikely to play a major role in power production before the 2060s or 2070s. "I think the science is great. But many engineering obstacles remain. We don't really know what the power plant would like."
The big challenge is sustaining the fusion energy long enough so that it can power electric grids and heating systems around the world. The US scientists' breakthrough is on a far smaller scale than what's needed to generate enough energy to run one power plant. Jeremy Chittenden, co-director of the Centre for Inertial Fusion Studies at Imperial College in London, said it's about what it takes to boil 10 kettles of water. He explained that in order to turn that into a power station, there is a need to make a larger gain in energy – substantially more.
Scientists also have to determine how to eventually reduce the cost of nuclear fusion for it to be used commercially. "At the moment we're spending a huge amount of time and money for every experiment we do. We need to bring the cost down by a huge factor."
