BEIJING - China will substantially improve its shale gas yield in the next decade and beyond, according to official guidelines.

Annual output is expected to reach 30 billion cubic meters by 2020 and then jump to a range of 80 to 100 billion cubic meters in another ten years, according to a document released by the National Energy Administration (NEA) Friday.

The goal represents a huge increase from the current level, 4.5 billion cubic meters last year, according to NEA data.

To realize this ambition, China will ramp up government subsidies, introduce more investors to the cash-starved sector and encourage cooperation with foreign companies in advanced prospecting technology.

China's exploitable shale gas reserves are estimated at 21.8 trillion cubic meters, with 544.1 billion cubic meters discovered.

Currently, only the United States, Canada, China and Argentina commercially produce shale gas.

The world's biggest energy producer and consumer, China is promoting the use of clean energy for greener growth.

The government has vowed to increase the proportion of natural gas used in its energy consumption to more than 10 percent from the current 5.9 percent. The global average is 24 percent.