Nuclear fusion may still be decades away, but the latest breakthrough could speed up its development

Researchers in California fired the world’s biggest laser at a capsule filled with hydrogen fuel, causing it to implode and starting fusion reactions.

Nuclear fusion holds huge promise as a source of clean, abundant energy that could power the world.

Now, fusion researchers at a national laboratory in the US have achieved something physicists have been working towards for decades, a process known as “ignition”.

This step involves getting more energy out from fusion reactions than is put in by a laser.

But just how close are we to producing energy from fusion that can power people’s homes? While ignition is only a proof of principle and a first step in a very long process, other developments are also in the works and together they could spark renewed enthusiasm for making fusion a practical reality.

First it’s important to recognise that the latest result is indeed a real milestone.

The researchers at the National Ignition Facility (NIF) in California fired the world’s biggest laser at a capsule filled with hydrogen fuel, causing it to implode and starting fusion reactions that mimic what happens in the Sun.

The fusion energy released by the implosion was more than that put in by the laser, a massive achievement given that, just a few years ago, the NIF laser could only get out about a thousandth of the energy it put in.