A geothermal energy resource that could supply millions of people with heating for decades has been uncovered in the eastern part of Shandong province.

The province's No 1 Institute of Geology and Mineral Resources has detected rock temperatures as high as 110 C at depth of 1,240 meters beneath the earth's surface.

Jing Xiaodong, from the institute, said temperatures could reach 150-200 C once the drill hole has reached a depth of 4,000 meters.

"This hot dry rock resource can be used to produce power in a very environmentally friendly way and the cost of generating power from hot dry rock is much lower than with coal," said Jing.

The institute has located two regions of hot rock under the cities of Weihai and Yantai.

If even 2 percent of the heat contained in these regions was utilized, it could supply Shandong with heat energy for 38 years, said Jing.