ALLIANT ENERGY CORPORATION
Solar energy battery projects get green light
Projects approved in Grant and Wood counties to improve energy reliability and resilience for customers

The Public Service Commission of Wisconsin (PSCW) approved two Alliant Energy battery energy storage projects totaling 175 megawatts (MW). The approval clears the way for construction to begin on the 100-MW Grant County Battery Project and 75-MW Wood County Battery Project. They will be located alongside the company's Grant County and Wood County solar sites. The integration of these battery systems with Alliant Energy's utility-scale solar sites increases customer access to safe, reliable energy even when the sun isn't out.

"We appreciate the PSCW's approval of these cutting-edge battery energy storage systems that will enhance grid reliability and flexibility for our customers," said David de Leon, president of Alliant Energy's Wisconsin energy company. "These projects are another step toward achieving our clean energy goals while enabling a more resilient and cost-effective energy future. We are excited to break ground on these innovative battery projects and look forward to the benefits and enhanced value these systems will deliver to our customers."

Alliant Energy expects to begin construction on both battery projects in early 2024. The Wood County project in the town of Saratoga is expected to be operational by the end of 2024 while the Grant County project in the town of Potosi is expected to be operational by mid-2025. They will have the capacity to power over 80,000 homes for four hours and 100,000 homes for four hours, respectively. Alliant Energy selected FlexGen, a leading energy storage solution and software technology provider, to provide the energy management system and battery energy storage equipment.  

"Alliant Energy is one of the country's most forward-looking and innovative utilities when it comes to energy storage and system reliability. These battery projects represent an incredibly important step toward creating a more intelligent and resilient grid," said Kelcy Pegler, CEO of FlexGen. "Battery energy storage resources are the key to the future of our infrastructure, and FlexGen is proud to deliver industry-leading services and value to our partner Alliant Energy and the customers it serves." 

The addition of energy storage capacity aligns with Alliant Energy's Clean Energy Vision, a comprehensive strategy to transition to cleaner, more efficient energy sources. These battery projects will complement Alliant Energy's growing portfolio of renewable resources, improve energy reliability and help to achieve the company's aspirational goal of net-zero carbon emissions from electricity generation by 2050. For more information on Alliant Energy's commitment to clean energy and its battery projects, visit alliantenergy.com/battery.

About Alliant Energy 
Alliant Energy Corporation (NASDAQ: LNT) provides regulated energy service to 985,000 electric and 425,000 natural gas customers across Iowa and Wisconsin. Alliant Energy's mission is to deliver energy solutions and exceptional service customers and communities count on - safely, efficiently and responsibly. Interstate Power and Light Company and Wisconsin Power and Light Company are Alliant Energy's two public energy companies. Alliant Energy is a component of the Nasdaq CRD Sustainability Index, Bloomberg's 2022 Gender-Equality Index, and the S&P 500. For more information, visit alliantenergy.com and follow us on LinkedIn, Facebook, Instagram and Twitter.

About FlexGen Power Systems Inc. 
Based in Durham, N.C., FlexGen is a leading integration services and software technology provider for energy storage solutions in the United States and globally. FlexGen designs and integrates storage solutions and the software platform that is enabling today's energy transition. Leveraging its best-in-class energy management software and power electronics, FlexGen delivers utility-scale storage projects integrated with traditional and renewable power generation globally. Our clients and partners include the most technically and commercially demanding developers, utilities, government agencies and industrial companies in the world. To learn more, please visit flexgen.com. 

This press release includes forward-looking statements. These statements can be identified because they include words such as "plan," "will," "targeted," "expected," or other words or expressions of similar import. Similarly, statements that describe planned battery storage facilities, our clean energy vision, transitioning our energy resources and other plans and strategies are forward-looking statements. These forward-looking statements are subject to risks and uncertainties that could cause actual results to differ materially from those expressed in, or implied by, the statements. Actual results could be materially affected by the following factors, among others: The inability to obtain regulatory approvals or necessary permits in a timely manner; state regulatory actions that delay or reject the proposed plans, or that include terms that make the plans uneconomical, including rate recovery levels and returns on equity; the inability to obtain necessary equipment and labor in a timely manner; the ability to complete construction of storage projects by planned in-service dates and within the cost targets set by regulators due to cost increases of and access to materials, real estate, equipment and commodities including due to inflation, tariffs, duties or other assessments, labor issues or supply shortages, the ability to successfully resolve warranty issues or contract disputes, the ability to achieve the expected level of tax benefits based on tax guidelines and project costs, and the ability to efficiently utilize the storage project tax benefits for the benefit of customers; work stoppages; adverse weather conditions; unforeseen engineering or technology issues; failure of equipment and technology to perform as expected; political conditions in Alliant Energy's service territories; changes to Alliant Energy's access to capital markets; adverse impacts resulting from the COVID-19 pandemic and responses to the pandemic; current or future litigation, regulatory investigations, proceedings or inquiries; and economic conditions in Alliant Energy's service territory. These factors should be considered when evaluating the forward-looking statements and undue reliance should not be placed on such statements. The forward-looking statements included herein are made as of the date hereof and Alliant Energy and Wisconsin Power and Light Company undertake no obligation to update publicly such statements to reflect subsequent events or circumstances.

Media Contact
Tony Palese
tonypalese@alliantenergy.com
(608) 458-3132

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