The U.S. Department of Energy announced the closure of a $5.1 billion loan package for Alliant Energy, a utility serving Iowa and Wisconsin.

The financing will fund construction of new natural‑gas‑fired power plants, efficiency upgrades to existing facilities, installation of battery storage systems and broader grid‑infrastructure improvements across both states.

The project targets a total capacity increase of 2.6 gigawatts, enough to supply electricity to roughly 1.8 million households.

The loan expands an earlier conditional offer of $3 billion made in January 2025 during the final days of the Biden administration.

DOE’s Office of Energy Dominance Financing, formerly the Loan Programs Office, is providing the funding as part of its broader effort to back large‑scale energy projects, including nuclear, natural gas and storage.

Gregory Beard, director of the loan office, said the new capacity will strengthen energy security and eventually lower electricity costs for families and businesses in the region, though cost reductions may take years to materialise.

The loan is part of a series of recent DOE commitments, including a conditional $5 billion loan to Constellation Energy for nuclear upgrades and similar financing to Vistra and Southern Company for capacity and grid improvements.