Leading article: A watershed for clean energy

Two events this week will set out very different visions of Britain's future in an age of accelerating climate change and diminishing supplies of oil – and very different views on how this country can lead the world. On Thursday Gordon Brown and Nicolas Sarkozy will meet amid much ballyhoo in the unlikely environment of Arsenal's Emirates Stadium, where they are expected to sign an agreement to build a new generation of nuclear power stations and to export the technology around the globe. And on Saturday, as we report today, a barge is set quietly to slip out of Belfast to install the world's first-ever commercial tidal power turbine in the much more attractive surroundings of Strangford Lough.

There are no prizes for guessing which will get the most attention, but in 20 years' time the story may be very different, for the low-key event in Northern Ireland may then well be seen either as the beginning of something radically new, or as a tragically missed opportunity. Which will depend on the decisions taken by Brown and Sarkozy, and by their counterparts around the world.

This is not merely an issue of nuclear versus renewables. True, Britain's record in this area is appalling. Blessed with by far the best renewable resources in Europe – tide, wave, and wind – we remain near the bottom of the European league when it comes to exploiting them.

True too, the nuclear industry – and, more particularly, a treacle layer of atavistic atomophiliacs in the civil service which seems to persist and reproduce despite changes in the departments dealing with energy – is largely responsible for this scandalous situation. There is plenty of evidence that the proper development of renewables in Britain has been stifled lest it pose the slightest threat to the nuclear dream. But this is about something even more fundamental, the whole direction in which society should develop.

Time and tide, they say, wait for no man, but tidal energy has been waiting for an awful long time for the men (and too few women) who run the country to realise its importance. Now, finally, they appear belatedly to have caught on and ministers have become enthusiastic converts to the Severn Barrage which, it is estimated, could by itself supply 5 per cent of Britain's electricity from an utterly predictable and dependable renewable source.

But they still have fully to realise the potential of the turbine which is about to start generating power, 12 years from the earliest date at which the barrage could possibly do so. Espousing a totally different technology – which draws energy from the currents as they run past, rather than impounding them behind a dam – is much cheaper, more flexible and faster to construct and get into operation. And its potential to supply Britain with power is just as great, maybe greater.

The issue is the same as with the nuclear obsession, whether to centralise or decentralise energy supply. Ever since Britain became the first country to develop a national grid in the 1930s, governments have sought to maximise centralisation. Ministers far prefer to make a few major decisions on building big power plants, than relying on a large number of smaller ones to save energy or to install small plants. But this will now have to start to change. One reason is that – apart from a few a typical instances like the Severn Barrage – renewables come in small packages: the sun, winds, waves, and tides are diffuse, distributed by nature for free, and they are best exploited accordingly. Decentralised energy is more efficient, as it suffers fewer distribution losses. It is cheaper, as the International Energy Agency has itself pointed out. And in an age of terrorism and disruption it is also, counterintuitively, more secure.

Gordon Brown has done well to resist pressure from John Hutton, his Secretary of State for Business, to scrap Britain's commitment to a European target to get 15 per cent of our energy – and thus 40 per cent of our electricity from renewable sources. It may be the only issue where he has recently stood up to the Blairites who were once his bitterest foes.

The Government has also gone part of the way to embracing the new imperative in its welcome plans to insist that all new homes are zero-carbon, generating their own energy. But the Prime Minister still falls far behind Chancellor Merkel of Germany, or even Mr Sarkozy, who are vigorously expanding decentralised programmes of small-scale renewables in their own countries. What is needed is balance, which so far the Government has woefully failed to provide – and a vision that stretches far beyond the Arsenal stands to the sea.