This report, prepared for Sierra Club, analyzes the cost of a U.S. Department of Energy (DOE) mandate that Unit 1 at the Craig coal-burning power plant in Colorado remain available and operate beyond its December 31, 2025, retirement date. Grid Strategies’ analysis predicts that a DOE order that requires Craig Unit 1 to remain available and operate for 90 days would cost at least $20 Million. That equates to approximately $85 Million per year. If DOE’s order effectively requires Unit 1 to operate in must-run status, these costs would likely increase to around $150 Million per year. The costs, and similar costs associated with renewals each 90 days, would likely be passed on to ratepayers.