Building a sun on earth

Scientists have unveiled the first piece of a massive nuclear fusion reactor, scheduled to be turned on in 2018. The international project, called ITER, will be a testing ground for the technology needed to make the world's first fusion power plants.

Efforts to harness the awesome power of nuclear fusion have been ongoing for decades, but have become ever more alluring as our demand for clean, abundant energy has soared. Fusion power - the energy source of the sun and stars - has the potential to produce massive amounts of energy, with no greenhouse gas emissions and only small quantities of nuclear waste.

ITER is, however, a fantastically expensive project, predicted to cost up to £18 billion. The UK puts £20 million into the kitty every year - almost half of our total energy research budget.

I wonder whether it's wise to invest so much in a single flagship project?

Image: NASA