This report analyzes pathways for decarbonizing Indian Railways (IR), the world’s second largest railway network and India’s largest electricity consumer. The study finds that complete decarbonization through a mix of solar and wind power would be 17-32% cheaper for traction operations and 40-61% cheaper for non-traction operations compared to business-as-usual by 2030. The authors recommend an accelerated captive generation pathway targeting 100% renewable energy by 2020, while prioritizing implementation in states with favorable net metering and open access policies. The report concludes that decarbonization would not only help India meet its climate targets but also bring significant cost savings to IR.