Wisconsin investor-owned utilities Madison Gas and Electric (MGE) and WEC Energy have received regulatory approval to buy a 200MW solar and 110MW battery energy storage system (BESS) in Kenosha County.
MGE and two WEC Energy subsidiaries have got the go ahead to buy the Paris Solar-Battery Park, which was developed by Invenergy and is set to become operational in 2023.
- MGE will own 20MW of solar and 11MW of BESS (10% of the total)
- WE Energies will own 150MW of solar and 82.5MW of BESS (75% of the total)
- WPS will own 30MW of solar and 16.5MW of BESS (15% of the total)
The total estimated cost of the acquisition is US$433 million according to a Final Decision filing (Docket 5-BS-254) from the Public Service Commission of Wisconsin. Wisconsin’s Citizens Utility Board has argued against the deal on the grounds it may not be the most cost-effective solution, in a brief to the commission.
It is MGE’s first ever battery storage which will serve its customers and the following quote from the Final Decision filing alluded to the Utility Board’s objections:
“Due to the novelty of battery storage technology for utility-scale applications, and based on the application materials, data request responses, and testimony received into the record in this proceeding, Commission staff’s financial evaluation was unable to verify the applicants support for the cost-effectiveness of acquiring 110 MW of BESS in this docket,” it read.
Energy-storage.news has asked MGE whether the park is true solar-plus-storage or just colocation with a shared connection to the grid and will update this article with their response.
A passage from the Paris solar park’s application to the Commission back in February doesn’t clarify this but gives an indication of the role the BESS will play:
“The impact to the MISO (Midcontinent Independent System Operator) grid from the integration of a BESS at Paris Solar will be positive, as the storage system can act as an “electrical suspension” system for the grid, to smooth out abrupt ups and downs in solar production that can occur on partly
cloudy days,” it read.
“The system can furnish other grid services such as frequency response, voltage support, and output scheduling to potentially shift some afternoon production to later in the day, if needed, to correspond with peak demands.”
WEC Energy aims to achieve a 55% emissions reduction by 2025 and a 70% reduction by 2030, and is investing US$2 billion in solar, wind and battery storage projects by 2025 to achieve this. Its two aforementiond subsidiaries plan to retire 1.6GW of fossil fuel generation by 2024.
It has filed a request for a similar project called to Paris called Darien which is also set to go live in 2023. That would involve more solar (250MW) but less storage (75MW) than Paris and cost around US$446 million under the same 90%/10% ownership structure between WEC and MGE. Paris’ solar portion is smaller than the initial 300MW plan announced last year.
The Midwest is behind market leaders like California and Hawaii (and to a lesser extent Texas and New York) but storage deployments could accelerate in the next few years as the region phases out coal, according to IHS Markit.