China's Shenhua Group will build the largest coal-fired power station in Asia over the next five years, the official Xinhua news agency said Tuesday, as the country struggles to meet its energy needs.

China's biggest coal company and officials in the Guangxi Zhuang Autonomous Region signed a deal for the 8-gigawatt thermal plant on Monday, according to Xinhua and the local government's website.

The plant would be built in the southern port city of Beihai to help ease power shortages caused by drought, which has strained power supplies.

China relies on coal for nearly 70 percent of its energy needs, which have soared in recent years as the country's economy grew at a blistering pace.

Power outages and rationing have been imposed in 17 provinces this year and shortages could worsen if coal supplies are not increased or if the country's north sees particularly harsh winter weather.

Shenhua's plans come days after local governments were ordered to reduce emissions of "major pollutants" by as much as 10 percent by 2015, amid growing public anxiety over bad air.

China is the world's biggest greenhouse gas emitter with many of its cities cloaked in a polluted haze.

Shenhua and the Guangxi government will ensure the new plant's eight power generators get a steady supply of coal from company mines in Indonesia and Australia by building four 100,000-tonne deepwater loading docks, Xinhua said.

Beihai city will also build a coal storage facility capable of handling 30 million tonnes a year in the nearby port of Tieshan.