Alliant Energy (“Alliant” or “the Company”) provides regulated energy service to approximately 1 million electric and 425,000 natural gas retail customers across Iowa and Wisconsin. Alliant Energy has two public energy companies that are principally engaged in the generation and distribution of electricity to retail electric customers, along with the distribution and transportation of natural gas to customers in primarily rural communities. This RFP may be used to meet capacity and energy needs for either of Alliant Energy’s regulated utilities – Wisconsin Power and Light or Interstate Power and Light. (1) Interstate Power and Light Company (IPL) provides electricity to approximately 500,000 retail electric customers and transports natural gas to approximately 225,000 customers across Iowa. (2) Wisconsin Power and Light Company (WPL) provides electricity to approximately 500,000 electric retail customers and transports natural gas to about 200,000 natural gas retail customers across Wisconsin. For more information, refer to Alliant Energy at www.alliantenergy.com.

In 2024, Alliant Energy will issue two (2) separate RFPs issued for MISO resources as detailed below. These two concurrent RFPs will be considered an All-Source solicitation process.

This RFP will target up to 1,500 MW of renewable resources. The Company will accept proposals from standalone renewable resources, hybrid renewable resources (renewable facilities paired with on-site storage) and standalone renewable resources that may be amenable to storage expansion at a later date.

This RFP will target up to 1,500 MW of thermal resources and standalone storage – both conventional and long-duration.

Alliant Energy has retained Charles River Associates (“CRA”) to manage the RFP processes for the purpose of creating the RFPs and soliciting responses. CRA will also serve as the independent third party to evaluate all proposals on behalf of the Company.

Several important milestone dates for the RFP processes are shown below: