But how big of a deal is “net energy gain” anyway – and what does it mean for future fusion power plants? Here’s what you need to know.
Existing nuclear power plants are operational split – Splits heavier atoms to produce energy. During fission, a neutron collides with a heavy uranium atom, splitting it into lighter atoms, releasing more heat and energy at the same time.
Fusion, on the other hand, works in the opposite way – it combines two atoms (mostly two hydrogen atoms) together to form a new element (mostly helium)., The same way stars create energy. In that process, both hydrogen atoms lose a small amount of mass, which is converted into energy according to Einstein’s famous equation, E=mc². Because the speed of light Very very fast – 300,000,000 meters per second – even a small amount of mass is lost and a ton of energy is gained.
What is a “net energy gain” and how did researchers achieve it?
At this point, the researchers were able to successfully combine two hydrogen atoms, but it always takes more energy to react than to get them back. Net energy gain — where they gain more energy than the reaction produces — is the elusive holy grail of fusion research.
Now, researchers at the National Ignition Facility at Lawrence Livermore National Laboratory in California are expected to announce a net energy gain by firing lasers at hydrogen atoms. 192 laser beams compress hydrogen atoms to 100 times the density of lead and heat them to about 100 million degrees Celsius. The high density and temperature binds the atoms together into helium.
Other methods involving the use of magnets to control the superhot plasma are being researched.
“If this is what we expect, it’s like a Kitty Hawk moment for the Wright brothers,” said Melanie Windridge, a plasma physicist and CEO of Fusion Energy Insights. “It’s like a plane taking off.”
Does this mean fusion energy is ready for prime time?
No. The scientists refer to the current progress as “scientific net energy gain” — meaning that more energy has come out of the reaction than was input by the laser. This is the biggest milestone ever achieved.
But this is only a net energy gain at the micro level. According to Troy Carter, a plasma physicist at the University of California, Los Angeles, the lasers used at the Livermore lab are only 1 percent efficient. That means it takes about 100 times more energy to operate lasers than hydrogen atoms can provide.
So researchers still need to achieve an “engineered net energy gain,” or the entire process takes less energy than is released by the reaction. They also need to figure out how to convert the energy released, currently in the form of kinetic energy from helium nuclei and neutrons, into a usable form for electricity. It can be converted into heat, heating the steam and turning the turbine to drive the generator. That process also has performance limitations.
This means that the energy gain has to be pushed much higher for fusion to be really commercially viable.
At the moment, researchers can only do one fusion reaction per day. In between, they must allow the lasers to cool down and change the fusion fuel target. A commercially viable plant would need to do that several times per second, says Dennis White, director of the Center for Plasma Science and Fusion at MIT. “Once you have scientific credibility, you have to find engineering credibility,” he said.
What are the benefits of affiliation?
The possibilities of fusion are enormous. The technology is much safer than nuclear power split, since fusion cannot produce runaway reactions. It produces no radioactive by-products to be stored or harmful carbon emissions; It is simply inert helium and produces a neutron. And we’re unlikely to run out of fuel: the fuel for fusion is just heavy hydrogen atoms, which are found in seawater.
When will fusion really power our homes?
That is the trillion dollar question. For decades, scientists have joked that fusion is always 30 or 40 years away; Over the years, researchers have variously predicted that fusion plants will be operational in the 90s, 2000s, 2010s and 2020s. Current fusion experts argue that it’s not a matter of time, but of will — if governments and private donors actively fund fusion, they say a prototype fusion power plant could be available in the 2030s.
“The timeline isn’t really a question of timing,” Carter said. “It’s a question of innovation and taking the initiative.”
