MGE Energy, Inc., through its subsidiaries, operates as a public utility holding company primarily in Wisconsin. It operates through Regulated Electric Utility Operations; Regulated Gas Utility Operations; Nonregulated Energy Operations; Transmission Investments; and All Other. The company generates, purchases, and distributes electricity; owns or leases electric generation facilities located in Wisconsin and Iowa; and plans, constructs, operates, maintains, and expands transmission facilities to provide transmission services. It also generates electricity from coal-fired, gas-fired, and renewable energy sources, as well as purchases power under short and long-term commitments. As of December 31, 2021, the company generated and distributed electricity to 159,000 customers in Dane County, Wisconsin; and purchased and distributed natural gas to 169,000 customers in seven Wisconsin counties. MGE Energy, Inc.is headquartered in Madison, Wisconsin.