US coal mines to turn into underground water batteries with new method

Researchers at Oak Ridge National Laboratory (ORNL) have developed advanced hydrodynamic and chemical modeling tools that enable the repurposing of thousands of abandoned US coal mines into underground reservoirs for Pumped Storage Hydropower (PSH). This innovation addresses a key limitation of traditional PSH, which requires significant elevation differences typically found only in mountainous regions. By utilizing deep mine shafts as lower reservoirs, the approach allows energy storage facilities to be built in flatter areas, reducing construction costs and accelerating deployment timelines. This method offers a sustainable solution for long-duration energy storage essential for a carbon-neutral grid while revitalizing former mining communities. The ORNL team’s models also tackle significant technical challenges such as chemical erosion and structural stability within the chemically active and complex mine environments. These simulations predict how water interacts with native minerals to assess corrosion risks and ensure the integrity of mine walls under high-pressure water movement, mitigating potential fractures or collapses. Moving forward, the researchers plan to conduct comprehensive techno-economic and system efficiency analyses to