Thirty years ago last June, Tony Benn and his wife skimmed along the Thames on a hydrofoil from Tower Pier to BP's Isle of Grain refinery in Kent. On his arrival, the then Secretary of State for Energy opened a valve and the first trickle of North Sea oil came ashore. Holding up a bottle of crude oil, Benn declared: 'I hold the future of Britain in my hand.'
Just a few miles from the Isle of Grain, government ministers, energy companies and planners are again talking excitedly about the future of Britain. This time the energy source is not oil but wind - the £1.5 billion construction of 270 turbines off the Kent coast. If planning permission is granted for the 'London Array', the world's biggest wind farm will be primed to generate 1,000 megawatts of electricity, supplying a quarter of the capital's needs.
Energy is the lifeblood of any developed economy, but alternatives to oil, gas and coal - so-called renewable energy sources such as wind and tide - have long been treated as a feeble joke, ringfenced for well-meaning but naive hairshirts and ethical investors.