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Duke Energy is one of the largest US utilities, with regulated utilities in the Carolinas, Indiana, Florida, Ohio, and Kentucky that deliver electricity to more than 8 million customers. Its natural gas utilities serve more than 1.6 million customers.

WEC Energy Group's electric and gas utility businesses serve electric and gas customers in Illinois, Michigan, Minnesota, and Wisconsin service territories. The company also owns a 60% stake in American Transmission Co. WEC's asset mix is approximately 49% electric generation and distribution, 30% gas distribution, 10% electric transmission, 9% unregulated renewable energy, and 2% LNG distribution and generation.

Alliant Energy is the parent of two regulated utilities, Interstate Power and Light and Wisconsin Power and Light. Together, IPL and WPL serve nearly 1 million electric customers and 425,000 natural gas-only customers. Both subsidiaries engage in the generation and distribution of electricity and the distribution and transportation of natural gas. Alliant also owns a 16% interest in American Transmission.

NRG Energy is one of the largest retail energy providers in the US, with 6 million customers. Vivint Smart Home, which NRG acquired in 2023, has 2 million home-services customers. NRG also is one of the largest US independent power producers, with 13 gigawatts of coal, gas, and oil power generation capacity primarily in Texas. The LS Power asset acquisition adds 13 GW of gas-fired power plants mostly in the Eastern US. NRG exited Chapter 11 bankruptcy as a stand-alone entity in December 2003.