Grant County — 300 MW hybrid plant, Grant County, WI

Grant County — 300 MW hybrid plant, Grant County, WI · Ask the Grid

Generation and physical site

EIA plant 65007 · Inventory for Aug 2026.

Reported operating nameplate by technology

Battery storage: 100 MW
Solar: 200 MW

Operating generators only. Battery power is in MW; stored energy is in MWh. These ratings do not establish a shared export limit.

Generator records (2)

EIA generator status and nameplate capacity for Grant County
Generator	Technology	Status	Power (MW)	Energy (MWh)
BESS1	Batteries	Operating	100	400
PV1	Solar Photovoltaic	Operating	200	Unknown

Physical map location · OpenStreetMap: 42.75254, -90.67527
Filed location · EIA: 42.71898, -90.70104

Sources and observation dates

Inventory source: EIA-860M workbook (preliminary)
EIA reporting month: Aug 2026
EIA retrieved: Oct 10, 2026
OSM extract: Oct 9, 2026
OSM last mapped edit: Jul 14, 2026
Map prepared: Oct 10, 2026
Field verification: Not reported

Reporting month describes the inventory. Retrieval and map preparation describe processing; an OSM edit does not establish an in-service date.

EIA source inventory

Units and generators

Operating generator records and technology attributes reported through EIA-860.

Generator	Capacity	Technology	Operation	Status
BESS1	100 MW 100 MW summer	Batteries Electricity used for energy storage · BA	Oct 2025	Operating
PV1	200 MW 200 MW summer	Solar Photovoltaic Solar · PV	May 2024	Operating

Related parties and identifiers

Parties, market resources, and identifiers tied to this asset, with owner, operator, developer, EPC, compliance provider, and interconnecting entity roles kept separate.

Relationship graph

Drag organizations to explore the network. Select a node to pin its details and available page link.

AssetContractorMarket / regulator

Parties and identifiers

OrganizationRoleBasis

Alliant Energy CorporationParent companyParent company

NextEra Energy Resources, LLC (subsidiary)Former owner / construction contractorPredecessor developer and solar EPC contractor

Public Service Commission of WisconsinRegulatorRegulatory authority

Reporting portfolio

EIA reporting entity

Wisconsin Power & Light Co

Entity 20856

Operating portfolio

33 plants

3 states

Reported capacity

5,776.7 MW

Batteries · Conventional Hydroelectric · Conventional Steam Coal

Largest reported plants in this portfolio
Largest reported plants	Capacity	State
Columbia (WI)	1,112 MW	WI
West Riverside Energy Center	727.6 MW	WI
Riverside Energy Center	674.9 MW	WI
Edgewater	413.7 MW	WI
South Fond Du Lac	381.6 MW	WI
Alliant Energy Neenah	371 MW	WI

Timeline and sources

Project milestones and public references behind the asset profile.

Project timeline

May 26, 2020
May 26, 2020
Alliant Energy announces six new solar projects in Wisconsinalliantener...
Alliant Energy announced plans to acquire and advance 675 megawatts of solar in six Wisconsin counties, including the 200 MW Grant County Solar Project developed by NextEra Energy Resources.
Aug 10, 2021
Aug 10, 2021
Grant County Solar project ownership transitions to Alliant Energyalliantener...
Ownership of the 200 MW Grant County Solar Project officially transitioned from a subsidiary of NextEra Energy Resources to Alliant Energy, following PSCW approval. Alliant Energy contracted a NextEra subsidiary to construct the project, with construction to begin in spring 2022.
Sep 2022
Sep 2022
Grant County Solar Project construction beginsalliantener...
Solar project construction began, employing more than 700 workers through completion.
View 1 more milestoneHide 1 milestone
1. Aug 9, 2023
  Aug 9, 2023
  PSCW approves Grant County Battery Projectalliantener...
  The Public Service Commission of Wisconsin approved the 100 MW Grant County Battery Project. Alliant selected FlexGen to provide battery energy storage equipment and energy management system. Construction expected to begin in early 2024, with operation expected by mid-2025.
May 2024
May 2024
Generator enters operationEIA-860
EIA-860 lists generator PV1 with this operating date.
May 30, 2024
May 30, 2024
Grant County Solar Project completion announcedalliantener...
Alliant Energy announced successful completion of the 200 MW Grant County Solar Project construction. Solar generator entered commercial operation in May 2024.
Oct 2025
Oct 2025
Generator enters operationEIA-860
EIA-860 lists generator BESS1 with this operating date.

Sources

PublisherReferenceType

U.S. Energy Information AdministrationEIA-860 generator inventoryFederal registry

U.S. Energy Information AdministrationEIA-923 generation filingsFederal filing

cleantechnica.comcleantechnica.compublic_source

Common questions about Grant County

Answered from the published record above. Questions whose inputs this profile does not carry are omitted rather than estimated.

How big is Grant County?

Grant County reports 100 MW battery storage + 200 MW solar of operating nameplate capacity. These technology ratings do not establish a common export limit. Source: EIA Aug 2026.

What kind of plant is Grant County?

Grant County is a Batteries, Solar Photovoltaic facility in Grant County, WI, participating in the MISO market.

Where is Grant County located?

Grant County is in Grant County, WI, inside the MISO balancing area.

Who operates Grant County?

Grant County is operated by Wisconsin Power & Light Co according to the EIA generator inventory. Reporting membership does not by itself establish ultimate ownership.

How much electricity does Grant County generate?

Grant County reported 380.4 GWh over the twelve months to 2026-07. Figures are net generation as filed to EIA-923.

How does Grant County compare to other plants?

By capacity, Grant County ranks #152 of 7,597 operating plants of the same technology nationally. It ranks #2 of 118 in WI.

Co-located assets

Plants within 25 km, nearest first, regardless of technology. Proximity is straight-line distance between mapped plant coordinates; it does not by itself establish a shared point of interconnection.

Cassville SolarSolar PhotovoltaicSolar Photovoltaic50 MW21 km Fennimore SolarSolar PhotovoltaicSolar Photovoltaic3 MW24 km

Overview

Infrastructure record

Overview

Infrastructure record

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Reported operating nameplate by technology

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Performance

Peer context

Monthly generation

Grid and market context

Nearby substations

Commercial, land, and environmental record

Transactions and agreements