The consumption of coarse coal in rural areas of Beijing fell by about 3 million metric tons in 2017, as authorities helped switch homes to clean energy alternatives, according to official data released on Tuesday.

Some 369,000 households in 901 villages went coal-free last year, taking the total since 2013 to 950,000, figures from the Beijing Commission of Rural Affairs showed.

Coarse coal is larger than 12.5 millimeters and contains impurities, as opposed to smaller fine coal.

Authorities across northern China have been phasing out coal-fired boilers in rural residences and replacing them with boilers that run on natural gas or electricity as part of efforts to reduce air pollution.

According to Li Ganjie, minister of ecology and environment, pollution caused by burning just 1 metric ton of coarse coal in a rural area is equal to that of a power generator burning 15 tons, as generators filter out much of the particulate matter in emissions.

Last year in Beijing, roughly 272,000 households shifted from coal to electricity, while 97,000 shifted to gas, according to the commission.

Amid efforts to switch homes from coal to cleaner alternatives, families across northern China were left without heat over the winter due to a shortage of natural gas, which prompted the central government to order local authorities to "ensure a warm winter" for families.

"All villages that completed the switch in Beijing received heating services as per normal this past winter," Kang Sen, deputy head of the commission, said in a statement.

The central government has issued a plan to have all villages nationwide abandon coal in favor of clean energy heating sources by 2020.

Kang said all rural communities on Beijing's plains will be coal-free by the coming winter, while work in the mountainous areas will start in villages near venues for the Beijing 2022 Winter Olympics.