As one of China's top 10 iron bases and a top six copper producer, Daye was once renowned as a major national coal-producing county-level area.

It holds proven reserves of 63 minerals, with an estimated 183 million metric tons of ferrous metal ore and 84.6 tons of gold, according to the Daye government.

In 2024, the city's mines yielded approximately 4.07 million tons of iron-manganese ore, almost 2.8 tons of gold, and 8.19 million tons of nonmetallic minerals.

The intensive mining in Daye, however, took a heavy toll on its landscape, leaving behind numerous open wounds such as the Baosheng mining pit.

Songwan's project, a green electricity and green hydrogen base built on the remediated land of the mine, is a marriage of necessity and innovation.

"We saw that these abandoned mines had unique 'three-dimensional space advantages'," said Zhou Hua, general manager of Lyuye Hydrogen Energy Co, the firm behind the project.

The concept was to use the mountain slopes to lay solar panels, convert the abandoned mine shafts into natural hydrogen storage caverns, and build the factory on the leveled land, he said.

"This kind of three-dimensional use turns idle resources that were previously unusable into developmental assets," he added.