Ministers or senior officials from 154 countries vowed to "substantially increase with a sense of urgency" the share of renewables in meeting world energy needs.

"Renewable energies, combined with increased energy efficiency, will become a most important and widely available source of energy and will offer new opportunities for cooperation among all countries," they said.

The communique, described as a political declaration, did not give a timetable for this nor set any other specific targets.

Delegates said this was a concession to the United States, an opponent to government intervention in the market place and which faces the biggest bill of all for weaning its economy off oil.

The meeting also issued a document of policy guidelines and an "action plan" -- a raft of 165 detailed promises by governments and corporations for promoting renewable sources.

Renewable energies comprise solar, wind, geothermal, biomass, wave and hydro power.

Today, they have just a tiny share of the world's energy mix. Much of the infant technology is still outgunned by fossil fuels, whose long reign has given them a huge cost edge in infrastructure, efficiency and lobbying power.

Interest in renewables has surged in the light of this year's dramatic rise in oil prices, driven in part by fears over supplies from Saudi Arabia and Iraq.

German Cooperation and Development Minister Heidemarie Wieczorek-Zeul said developing countries faced an estimated 60-billion-dollar increase in their oil bill, and this helped explain their support in Bonn.

"This conference was a success," she said. "There are sometimes in politics, big successes."

The four-day meeting, hosted by Germany, gathered around 3,000 ministers or senior officials, corporate executives, energy users and green activists.

The declaration said countries were "committed to achieving tangible progress as well as substantive followup" and planned to "continue the high-level political dialogue begun in Bonn."

When and where this meeting will take place was not spelt out, but it is expected to take place by the end of 2006, and China -- lauded in Bonn for its renewables policy -- is rumoured as a possible venue.

Green activists, relentless foes of fossil fuels whose pollution is blamed for global warming, were ecstatic at the outcome.

They were delighted there would be monitoring of the action plan, thus setting a benchmark to which pledgers would be held accountable.

And, they believed, further meetings would guarantee that the cause of renewables would not wither away, as happened in the 1980s when oil prices tumbled and undercut green power.

"One of the main breakthroughs is that renewable energy, instead of being an odd technology in the corner, is now recognised as playing a major part of the world's energy future," said Jennifer Morgan, director of WWF's climate-change programme.

"The Sun has just cracked the horizon on the dawn of the renewable energy revolution," said Greenpeace International's political director, Steve Sawyer.

But he stressed governments urgently had to give renewables help through tax breaks, regulatory support and political backing.

Renewables contributed just five percent of world energy supplies in 2000, but accounted for 19 percent of electricity production, mainly through hydro plants, according to the Paris-based International Energy Agency (IEA).

By comparison, oil accounted for 38 percent of energy supplies, coal and gas 50 percent, and nuclear seven percent.

Margaret Beckett, Britain's secretary of state for the environment, said the task ahead was huge.

Quoting IEA estimates that the world needed to invest 16 trillion dollars to meet its energy needs by 2030, she warned "we need a transformation of unprecedented scale and urgency" to give renewables a central role.

SPACE.WIRE