Northern Indiana Public Service Company LLC, a subsidiary of NiSource Inc., on Oct. 31 filed its 2018 integrated resource plan with the Indiana Utility Regulatory Authority, detailing a strategy to retire its coal-fired generation portfolio over the next decade and transition to more cost-efficiency renewable energy. The resource plan charts a path to meet customer electric needs over the next 20 years. The utility plans to close the 1,780-megawatt R.M. Schahfer Generating Station in Wheatfield by 2023 and 469-megawatt Michigan City Generating station in Michigan City by 2028. The changes are expected to result in over $4 billion in cost savings for customers over the long term and lower carbon emissions by more than 90 percent by 2028. To replace the coal plants, the company plans to pursue renewable energy resources such as wind, and solar, as well as battery storage technology. NIPSCO’s current resource portfolio consists of hydroelectric, wind, demand-side resources, and natural gas-fired sources in addition to the coal-fired plants.