SINGAPORE - China's coal output hit record highs in December and in the full year of 2021, as the government continued to encourage miners to ramp up production to ensure sufficient energy supplies in the winter heating season.

China, the world's biggest coal miner and consumer, produced 384.67-million tonnes of the fossil fuel last month, up 7.2% year-on-year, data from the National Bureau of Statistics showed on Monday. This compared with a previous record of 370.84-million tonnes set in November.

For the full year of 2021, output touched a record 4.07-billion tonnes, up 4.7% on the previous year.

Since October, authorities have ordered coal miners to run at maximum capacity to tame red-hot coal prices and prevent a recurrence of September's nationwide power crunch that disrupted industrial operations and added to factory gate inflation.

The most-active thermal coal futures contract on the Zhengzhou Commodity Exchange, for May delivery, was up 2.82% at 708 yuan per tonne at 02:39 GMT on Monday. Prices have more than halved since hitting record highs in October last year.

Coal traders in China shrugged off an Indonesian coal export ban as stockpiles at power plants were strong and power demand was set to weaken for the upcoming Lunar New Year holidays.

Coal inventory at Chinese utilities exceeded 162 million tonnes on January 21, or 21 days usage, about 40-million tonnes higher than the same period last year, the state planner National Development and Reform Commission said on Friday.

Coal supply was guaranteed, the state planner has said, even as coal inventories were "slightly fluctuating" from a record high of 168-million tonnes struck on December 22, it added. They remained above 160-million tonnes, exceeding levels in the prior year.

Meanwhile, China's 2021 power consumption rose 10.3% year-on-year to 8.31 trillion kilowatt hours (kWh), the National Energy Administration said in a separate statement on Monday.