Good . Now we can dismantle all the wind mills , oil
platforms.
With fusion energy water can be turned into fuel by mixing it with
carbon dioxide.

excerpt guardian.co.uk

Iter began life in 1985, at a summit in Geneva between Ronald Reagan
and Mikhail Gorbachev. They called for scientists to prove that fusion
was a scientifically and economically viable way of producing
electricity. Europe and Japan soon joined Russia and the US as
partners in the project.

Eighteen years on, and countless designs, experiments and tests later,
the project now also involves China, Canada and South Korea, and the
plan is to build a huge ó4.5bn (£3bn), 17m high reactor by the end of
the decade.

Where the reactor will be built remains up for grabs. The shortlist
will be composed of three sites: Rokkasho in Japan, Clarington in
Canada and either Cadarache in France or Vandellos in Spain (the EU
wants to submit one of these sites to avoid splitting the final vote
later this year).

The competition is being fought fiercely - aside from the kudos of
having the world's largest fusion reactor on their doorstep, the
winning site will get an economic boost from more than a thousand
(highly-paid) scientists and support staff who will eventually live
and work there.

In the end the decision may be made for political, rather than
scientific, reasons. Rumours abound that, thanks to recent events, the
US wants Europe to put forward the Spanish rather than the French site
as its candidate. Whatever politics get in the way, though, they will
just be a temporary distraction from the burgeoning new era for the
scientists. Already, they are being asked to address the issues
related to generating large amounts of power, rather than the basic
aspects of whether or not their designs will work in the first place,
according to David Ward, a fusion physicist at Culham. "We've never
had to do that before," he says.

Llewelyn-Smith says that there's never been a better time for
believing that fusion will work. "There's been terrific progress not
least because of Jet, and technology has moved on," he says. "Fusion's
time has come."

How fusion works

At the heart of each star swim countless billions of hydrogen nuclei
(single protons). They fuse to form helium nuclei (two protons and two
neutrons), plus energy. This doesn't happen easily, however. Despite
the immense gravitational pressure and temperature at the core of
every star, it takes millions of years to fuse two nuclei together,
such is the repulsive force between two protons.

On Earth, generating energy using a reaction that takes so long would
be next to useless. So, instead of hydrogen, physicists fuse two of
its isotopes - deuterium and tritium. The nuclei of these heavier
elements can be made to fuse more easily.

Deuterium is abundant in sea water. Tritium is harder to come by and
has to be made inside a fusion reactor. Even so, we have enough
resources to last several million years. The fuel is placed inside a
torus (a donut-shaped chamber) at the centre of the machine and heated
to create plasma at 100m C. The deuterium and tritium fuse to form
helium, energy and spare neutrons (which are absorbed by a lithium
shield around the torus). When the neutrons hit the metal, more
tritium is produced, and this is fed back into the torus.

As well as virtually limitless fuel, physicists say fusion itself
produces no dangerous waste products. There are secondary reactions,
however, that produce radioactive materials. But these have short
half-lives and become safe in a few hundred years, as opposed to the
thousands of years with fission waste.