Energy storage

As the electric grid continues to evolve, Alliant Energy is leading the way with new and innovative solutions. We are working to integrate emerging technologies and optimize energy resources such as wind and solar power, battery storage and traditional generation systems. These efforts will benefit our customers with improved energy reliability and efficiency.

The expansion of energy storage infrastructure is key to accelerating the transition to cleaner, more sustainable renewable energy. With major transformations underway, we’re working rapidly to balance energy demands, reduce the need for traditional power grid updates and increase security in the event of an outage or severe weather.

Header video: Battery system in Cedar Rapids, Iowa

Photo caption: Battery system in Wellman, Iowa

In August 2023, Alliant Energy received approval from the Public Service Commission of Wisconsin (PSC) to construct utility-scale battery storage facilities co-located at two of our solar sites.

The 100-MW battery project at Grant County Solar and 75-MW battery project at Wood County Solar represent a significant expansion of our battery storage capacity as we continue to transition to cleaner and more sustainable renewable energy sources. These systems will have the capacity to power over 100,000 homes for four hours and 80,000 homes for four hours, respectively.

In addition to the two solar battery sites, we received approval from the PSC to construct the 99-MW Edgewater Battery Project in Sheboygan, Wis. The system will have the capacity to power over 100,000 homes for four hours and will be located adjacent to our Edgewater Generating Station.

We anticipate completing all three projects by Fall 2025.

Alliant Energy and our project partners, including WEC Energy Group, Madison Gas and Electric, UW-Madison, Madison College, Shell Global Solutions US and the Electric Power Research Institute, are teaming up to construct one of the most sustainable, advanced energy storage systems in the country. The 200-megawatt hour Columbia Energy Storage Project would be the first of its kind in the United States and represents a significant advancement toward a more reliable, resilient and cost-effective energy future.

Utilizing a system design by Energy Dome, this innovative and efficient approach to long-duration energy storage is both simple and sustainable. The Columbia Energy Storage Project will take energy from the grid and store it by converting CO₂ gas into a compressed liquid form. When energy is needed, the system converts the liquid CO₂ back to a gas, which powers a turbine to create electricity.

The facility will be built south of Portage, Wis. in the Town of Pacific, near the current Columbia Energy Center. Pending approval, construction is expected to begin in 2026 and be completed by the end of 2027.

Photo caption: Energy Dome’s CO₂ battery located in Sardinia, Italy.

This microgrid pilot project – the first of its kind in Wisconsin – creates a small-scale power grid with islanding capability, meaning it can be disconnected from the traditional grid to operate independently in the event of a power outage or service disruption.

When disconnected from the central grid, microgrids serve customers in a defined area with power from one or more distributed energy resources such as battery, wind, solar or a combination thereof to improve reliability.

The Boaz microgrid system was completed in 2023. It is one of several advanced research pilot projects operated by Alliant Energy as we continue to expand access to energy storage solutions.

Pioneering microgrid project completed in Richland County (Alliant Energy news release, Aug. 24, 2023)

Photo caption: Microgrid system in Boaz, Wisconsin

Battery storage units maximize the value of our renewable energy assets and deliver greater efficiency. This storage capacity allows us to store electricity that is generated when demand is low. When the sun goes down or energy demands increase, we can release this stored battery power onto the grid and deliver safe, reliable energy to customers when its needed.

These energy storage solutions improve reliability and better meet customer needs – all while reducing reliance on fossil fuels and avoiding costly infrastructure upgrades.

We currently have several battery storage pilot units in operation and continue to evaluate potential development opportunities to harness more locally generated power and accelerate our transition to renewable energy. Additional information about our plans to advance sustainable energy solutions can be found in our Clean Energy Blueprint.

Photo caption: Battery system in Portage, Wisconsin