Battery energy storage solution at Columbia Energy Center


Alliant Energy is developing a 20 megawatt (MW)/200 megawatt-hour (MWh) CO2 battery long-duration energy storage solution at the existing Columbia Energy Center in Pardeeville, Wisconsin. Alliant Energy has contracted the equipment engineering and supply from Energy Dome, an Italian company.

The CO2 battery is a long duration, large-scale energy storage system based on a thermodynamic process that efficiently stores energy by manipulating CO2 under different conditions in a closed thermodynamic transformation. The CO2 battery can operate in charging mode, absorbing power from the grid; and discharging mode, returning power to the grid.

Alliant Energy applied for and was awarded a project grant from the U.S. Department of Energy’s (“DOE”) Office of Clean Energy Demonstrations (“OCED”). The project requires execution per the DOE requirements, which is a gated execution methodology where the phases are sequential and do not overlap. This will be the first project constructed in the United States by Energy Dome, and the second project of this size in the world. The BOP final completion date is currently forecasted for third quarter 2027.

Alliant Energy requests proposals for Engineer of Record services per the requirements listed herein. Given the nature of this new technology, Alliant Energy is looking for an engineering partner that brings a diverse offering of professional services to support project success.

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Short-term electric capacity (2028-2033)


Alliant Energy is seeking binding proposals for the acquisition of Zonal Resource Credits (ZRCs) within the Midcontinent Independent System Operator (MISO) region for the 2028/29 through 2032/33 planning years.

Key highlights:
  • Capacity type: MISO ZRCs, unit-contingent “As Generated” capacity, financial or non-MISO-based hedging offers and either seasonal or annual capacity exchanges.
  • Zones: MISO Zones 1–7 (preference for Zone 3).
  • Volume: min 25 MW per season or year.
Proposal submission:

Alliant Energy reserves the right to accept or reject any proposal at its sole discretion and encourages all qualified parties to participate.

Full details document [PDF]

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