More Chinese cities are switching from coal to natural gas to fight smog.

The gas supply-demand gap, which has been widening in recent years, hit a record in 2013 at 22 billion cu m.

Wu Xinxiong, head of the National Energy Administration, said the government will strive to ease the shortfall this year by using multiple strategies.

He told the annual national energy work conference on Tuesday that unconventional natural gas development will assume a larger role in adding new gas supplies.

"By 2020, China's coal gas output will grow to more than 50 billion cu m, accounting for 12.5 percent of domestic natural gas production," said Wu.

Wu said the government will make greater efforts to build new gas storage facilities to achieve better control of gas utilization.

At least nine storage facilities were put into operation in 2013 with total capacity of 11.2 billion cu m, taking China's storage capacity to 15.9 billion cu m.

Several companies - including State-owned PetroChina Co Ltd and China Petrochemical Corp (Sinopec Group) - have gas storage projects on the drawing board, according to the report.

Duan said the investors in gas storage projects will become more diverse, as State capital, private and foreign investors all participate.

"Commercialized natural gas storage is in its infancy in China, but it will be more tightly regulated and diversified in the future," she said.

The report said China's natural gas storage capacity will exceed 30 billion cu m by 2020.

Including other means by which natural gas is stored, such as LNG, China's total natural gas storage will account for 10 percent of its annual consumption, which is the world standard.

In contrast to natural gas, the nation's oil use growth decelerated in 2013. Crude oil consumption was up 2.8 percent last year to 487 million metric tons. The growth rate was 1.7 percentage points lower than in 2012, according to the institute.

Imported oil accounted for 58.1 percent of the country's oil supply, said the report.

During the first decade of this century, China's oil consumption consistently rose, with average annual growth of 6.7 percent. That trend ended in 2011.