Is the holy grail of energy finally within reach... and will it work?

Since the first demonstration in the 1930s, hundreds of reactors have been built all over the world. Not one has produced a single gigawatt of energy, nor will they for decades. But that’s not the point, writes Steven Cutts

The Tokamak nuclear fusion reactor design was first proposed in the 1950s, and is still used today (EPA/NFRI)

It’s been around for so long that it’s almost gone out of fashion. Nuclear fusion has been and remains the holy grail of energy research and it’s about to take a giant leap forward. In Provence, the world’s largest and most exciting nuclear fusion research facility is finally taking shape. The cost overruns are almost as astonishing as the engineering itself. At the beginning of the century, it was suggested that Iter, the world’s largest fusion experiment, could be built for around €6bn. By the middle of this decade, when it is fully operational, total costs will be at least 10 times greater than that. Big science has a habit of overrunning its initial budget but Iter is in a league of its own.

As long ago as the 1930s, nuclear fusion was demonstrated in a lab at the University of Cambridge. A team led by Ernest Rutherford achieved the impossible using equipment that would seem tiny and primitive to the modern physicist. Since then, over 100 fusion reactors have been built around the world. Not one of them has produced a single kilowatt of electricity. Neither will Iter. The option to generate electricity has not been engineered into the Iter project. Its purpose is to do something that no previous fusion reactor has ever done: gain.