China, which has rattled energy markets with its ravenous appetite for oil, declared on Friday that it would generate 10 percent of its power through renewable sources by 2010.
The pledge, made at a conference on renewable energy held here, surprised experts with its ambition. If China achieves its goal, they said, it will become a world leader in developing alternatives to fossil fuels, rather than just a world-class consumer.
"The Chinese want to do this on a massive scale," said Christopher Flavin, the president of the Worldwatch Institute, an environmental research organization in Washington. "They're very serious about it."
China faces an urgent need to diversify beyond oil and coal, he said. There are already sporadic power shortages in its teeming cities. The bill for Chinese oil imports is skyrocketing, as its economy grows at nearly double-digit rates and cars and trucks choke Chinese streets.
"China is saying that it sees the rapid development of renewable energy as being in its strategic interest," Mr. Flavin said.
China's initiative is part of a draft law on the use of renewable energy. In setting a numeric goal, Beijing has lined up with the European Union, which has pledged to generate 22 percent of its electricity, and 12 percent of all its energy, from renewable sources by 2010.
The United States rejects benchmarks for the adoption of renewable energy, and the Bush administration has rejected the Kyoto Protocol, the environmental treaty that imposes strict reductions on greenhouse gas emissions linked to global warming.
Critics note that these targets are purely voluntary, with no sanctions if they are missed and no well-established review process to determine how well they are being met. The European Union warned recently that its 25 member states might fall short of their target for 2010.
Moreover, energy consumption in China is rising so rapidly that even a national campaign to build windmills or solar-powered houses will barely reduce the country's dependence on fossil fuels.
The Chinese government said it planned to generate 60 gigawatts of energy from renewable sources by 2010 - most from small-scale hydroelectric projects - and 121 gigawatts by 2020. But the share of total electricity from renewable sources will rise to only 12 percent, from 10 percent.
"This is a problem in all industrializing countries," said Janet L. Sawin, a research associate at Worldwatch. "We haven't been doing as much with energy efficiency as with energy production."
Still, China's announcement allowed the German officials who played host at the conference to claim a victory.
"This commitment was amazing," said the minister for economic cooperation and development, Heidemarie Wieczorek-Zeul.
The timing of the conference could not have been more propitious. Crude oil prices surged to highs this week after a terrorist attack in Saudi Arabia, while ministers from the Organization of the Petroleum Exporting Countries held an emergency meeting to lift production quotas.
But amid a recognition that renewable energy ought to be a priority again, there were troubling signs. The International Energy Agency released a study that showed renewable energy actually lost ground, as a percentage of the total supply of power, from 1970 to 2001.
And while some countries, notably Denmark and Germany, have made big strides in wind energy, the progress has not spread widely. In 2001, about 86 percent of the world's capacity for wind generation was in Denmark, Germany, Spain and the United States, the report said.
The German chancellor, Gerhard Schröder, announced 500 million euros ($610 million) in low-interest loans to support renewable-energy projects and energy efficiency in developing countries. The World Bank said it would increase lending for projects by 20 percent a year over the next five years.
The United States kept a low profile, sending an assistant energy secretary, while most countries sent ministers. It promised research money to make solar and geothermal energy more cost-efficient.
If the United States is not a favored guest at such gatherings, however, it is also no longer a pariah. Most delegates avoided criticizing the Bush administration - at least outside of hallway chatter - and German officials said the American delegation played a "constructive role."