Nuclear fusion, or fusion for short, is what powers the Sun: deep in the Sun’s core, the nuclei, or central parts, of hydrogen atoms smash together, releasing energy in the process.
If we got this going on Earth, it could provide us with clean energy for millions of years. From just one gram of hydrogen, which we could extract from water, fusion could produce more energy than 15,000 tonnes of petrol, with zero greenhouse gas emissions.
However, fusion in labs has always taken more energy to get started than it produced.
But in 2014, the internet erupted with news. A team from the National Ignition Facility (NIF) in the U.S. had managed to get nuclear fusion going by using a giant laser to supply energy to a sample of hydrogen fuel.
The fuel released more energy through fusion than it received – a scientific first, and an achievement the team described as “a key step on the way” to making fusion a practical energy source.
So are we on the verge of tackling climate change and solving the world’s energy problems?
In short, no.
A closer look:
The team published a report about their experiment in Nature. If you look closely, you can find some signs that their results aren’t as promising as they first sound.
Firstly, the fuel released 17 kilojoules of energy, after receiving 10 kilojoules from the laser. But running the laser took 1,900 kilojoules.
Since it consumes more energy than it produces, it’s still not an effective way of generating power.
In addition, the team used a pellet of hydrogen the size of a flea – nowhere near what a full-fledged power station would need.
Simply ncreasing the amount of fuel is easier said than done – getting nuclear fusion started in this tiny sample still required the most powerful laser in history.
So before the team’s method can become feasible for electricity generation, they need a hundredfold increase in efficiency and a revolution in laser physics. Given that it has taken scientists almost 70 years of fusion research to get to this point, that’s not going to happen any time soon.
Fusion is not the solution:
Fusion is decades away from being a practical power source. But to stop climate change, we need to make big cuts to emissions way before then.
Research funding would be much better spent on improving renewable energy. Yet governments are still putting massive amounts of money into fusion research, such as the multibillion dollar ITER fusion project, which is being funded by 35 countries.
You may well be appalled by these facts. And you may also feel that you are powerless to change the situation.
But you’re not. You can speak up, and let your government know that you would like your taxes to be spent more effectively.
You can also raise awareness – many people don’t even know what fusion is.
You can’t change this all by yourself. But if you speak out, you can make a difference.