Old coal mines are hiding a clean energy secret, and this one town just figured it out

The former coal-mining town of Cumberland is becoming a powerful example of how abandoned fossil-fuel infrastructure can be repurposed for clean energy. After more than 80 years of coal extraction, the underground tunnels beneath the town may now help heat and cool buildings using geothermal energy. Researchers working with the University of Victoria’s Accelerating Community Energy Transformation (ACET) initiative are studying how water trapped inside the old mine shafts can function as a massive underground thermal battery.