Chinese hydro capacity up 50 per cent by 2015

National Energy Administration director Zhang Guobao said the expansion was necessary for China to meet its target of reducing carbon intensity by 40-45 percent by 2020 based on 2005 levels, Internet portal Sina.com said.

Carbon intensity measures the amount of greenhouse gas emitted per unit of economic activity.

China has also pledged to generate 15 percent of its energy from renewable sources — mainly wind and water — by 2020.

"We will take the initiative to deliver that promise even though the task is not easy at all," Zhang said in an interview with Sina.com. "We still have a lot of basic work to do."

State media reported last year that China expected to boost its hydropower capacity to 300,000 megawatts by 2020.

China is dependent on high-polluting coal for 70 percent of its energy needs, and the government is developing renewable sources such as wind and hydropower in a bid to improve the environment and to secure future supply.

It will host an extra round of climate talks in October before a UN summit in Mexico at the end of the year, as nations attempt to devise a successor to the Kyoto Protocol, which expires in 2012.