FlexGen begins operating 700MWh BESS in Wisconsin, Iowa for Alliant Energy

By Global Infrastructure Sherpa · Feb 9, 2026

Development Storage operational Wisconsin, Iowa, USA

700 MWh

Capacity

operational

Stage

Wood County BESS, Wever BESS

Project

FlexGen, a software-focused battery energy storage system (BESS) integrator, has put two utility-scale BESS projects in operation in Wisconsin and Iowa, US, totaling 700MWh. The projects were designed and built for utility Alliant Energy. The 75MW/300MWh Wood County BESS in Wisconsin and the 100MW/400MWh Wever BESS in Iowa will provide Alliant Energy with increased flexibility and help prevent customer costs associated with equipment replacement or constructing new lines and poles to meet rising energy demands. FlexGen is also providing system integration services using its HybridOS energy management software (EMS).

Deal Analysis

FlexGen's commissioning of two utility-scale battery energy storage systems (BESS) totaling 700MWh for Alliant Energy in Wisconsin and Iowa represents a significant step in grid modernization. The projects, the 75MW/300MWh Wood County BESS and the 100MW/400MWh Wever BESS, will enhance Alliant Energy's operational flexibility and potentially mitigate costs associated with traditional infrastructure upgrades. FlexGen's role as both developer and system integrator, leveraging its HybridOS energy management software, underscores the increasing importance of software solutions in optimizing BESS performance and grid integration. This deal highlights the growing trend of utilities adopting BESS to address rising energy demands and improve grid resilience. The size of the projects, particularly the 400MWh Wever BESS, demonstrates the increasing scale of utility-scale storage deployments. The partnership between FlexGen, a specialized BESS integrator, and Alliant Energy, a regional utility, exemplifies the collaborative approach necessary for successful energy transition. The operational status of these projects further validates the viability and maturity of BESS technology for grid-scale applications.

700MWh of BESS capacity brought online across two projects in Wisconsin and Iowa.
Alliant Energy leverages BESS to avoid traditional infrastructure investments.
FlexGen provides both development and system integration services, showcasing its comprehensive capabilities.
The deal underscores the growing importance of energy management software (HybridOS) in optimizing BESS performance.

Market Context: The North American energy storage market is experiencing rapid growth, driven by increasing renewable energy penetration, grid modernization efforts, and declining battery costs. Utilities are increasingly turning to BESS as a cost-effective and flexible solution for managing peak demand, improving grid reliability, and integrating variable renewable energy sources.