This photo shows Jangseong Coal Mine in Taebaek, Gangwon Province, March 3, 2022. Yonhap

Korea's biggest coal mine, Jangseong Coal Mine, formally closed Friday, 88 years after it opened, as coal output declined with the nation shifting toward greener energy sources.

The anthracite coal mine in Taebaek, some 180 kilometers east of Seoul, began operations in 1936 during Japan's colonial rule of the Korean Peninsula and went on to produce 94 million tons of coal.

Run by the Korea Coal Corp., the state-run mining firm, the mine's closure was decided last year.

In 2012, the mine produced 566,000 tons of coal, but its annual output plunged to 67,000 tons last year.

With Jangseong Coal Mine closed, Dogye Coal Mine in Samcheok, some 195 kilometers east of Seoul, will be the only remaining mine maintaining operations under Korea Coal.

Dogye Coal Mine is also scheduled to be closed next year.

"The government plans to provide support so that regions with closed coal mines, including Taebaek, continue to play a key role even in the era of carbon-free energy," Industry Minister Ahn Duk-geun said in a statement.

Meanwhile, the city of Taebaek seeks to establish production facilities for clean methanol at the site by 2029. (Yonhap)