Fusion would create no hazardous waste, and could be fuelled from the sea for millions of years. However, the main thing that fusion generates at the moment is bills: JET alone has an annual budget of pounds 54m. But scientists do not think a fusion power station will be feasible until the middle of the next century, 100 years after the concept was devised.
Europe's flagship nuclear fusion programme has achieved a new record power output, taking the world another small but significant step down the long road to a virtually unlimited, environmentally friendly fuel source. Earlier this week the Joint European Torus (JET) in Abingdon, Oxfordshire, set a new record by generating more than 12 megawatts of fusion power - the same process that fuels the sun. This set a record for the ratio of power generated to power input: JET achieved an "efficiency" of 50 per cent, double that achieved before.