Geological workers in East China's Shandong province have found four reserves of hot dry rock, which equal about 18.8 billion tonnes of standard coal, local authorities said Wednesday.
A geological team managed to dig into the rock in the cities of Rizhao and Weihai, according to the Shandong Bureau of Coal Geology.
Covering an area of 1,500 square km, the rocks can be used in fields such as power generation, heating and oil exploitation.
Hot dry rock is a kind of geothermal energy that contains no water or steam. It is usually found 3 km to 10 km below the earth's surface, with temperatures higher than 180 degrees Celcius.
The renewable and pollution-free resource, with rich reserves and stable output, is believed to have great potential to replace fossil fuels in the future, according to the bureau.