Each year, hundreds of millions of tons of overburden and waste rock are moved by mining operations nationwide. The Big Mass Battery Clinic team is developing a method to take advantage of this unused mass to store power from renewable energy sources. The proposed device stores renewable energy as potential energy by elevating this mass when excess grid power is available and releases energy by lowering the mass when demand exceeds baseload capacity. The team has demonstrated the feasibility of this device and developed models to inform its implementation.