The country, the world's biggest energy consumer after the US, currently ranks sixth among wind-power markets, according to Vestas CEO Ditlev Engel.

China wants sources including solar, wind and biomass to account for 10% of energy supplies by 2010 and 15% a decade later. Vestas last month reiterated a forecast for sales to climb about 17% this year as it boosts production capacity in China and the US, two of the company's biggest growth markets.

Vestas will complete its seventh China factory by the first quarter of next year, bringing total investment to $80m according to Engel. The company's China workforce has risen 20-fold to 1,000 from 50 in 2005, he said.

Higher oil and gas prices, as well as state subsidies and incentives worldwide, have encouraged investment in energy from renewable sources such as wind.

The Chinese government will give tax breaks, subsidies, fiscal incentives and establish special funds to boost the development of renewable energy, Chen Deming, vice chairman of the National Development and Reform Commission, said this month.

The nation plans to have one gigawatt of wind-power capacity by 2020 in offshore areas, according to the commission, the country's main economic planning body. Total wind farm capacity will have 30 gigawatts by then, it said.

ARTIC SEA OPENS Arctic sea ice shrank to the smallest area on record this year, covering 22 percent less of the ocean than the previous low in September 2005, scientists said.

Sea ice covered 4.1m sq km on 16 September 16, the US National Snow and Ice Data Center said in a statement on its Web site, using a "ve-day rolling average. That's 1.2m sq km less ice than the previous record . . . or an area roughly the size of Texas and California combined.

The retreat of ice has added urgency to the debate on climate change, and prompted a scramble by countries including Russia and Denmark for ownership of the Arctic seabed and its mineral deposits. The decline also threatens to unbalance Arctic habitats, posing a danger to species including polar bears.

This year's sea ice matched the 2005 record in August, with a month of melting left to go, an indication an ice-free North Pole may occur in coming years.