Data Center Registry
APECS Data Center Campus (Former GM Assembly Plant)
Janesville, Rock County, Wisconsin
APECS Data Center Campus (Former GM Assembly Plant) is a proposed data center in Janesville, Wisconsin (Rock County), operated by Viridian Acquisitions LLC. The public record puts it at announced November 2025, 800 MW planned, 250 acres, a reported $8 billion investment. It is the subject of active public debate, with hearings, petitions, or organized opposition on record.
Every line on this page traces to a public source listed at the bottom. Where a figure was looked for and not found, the row says so. A blank is never a zero.
Facility record
Proposed
- Operator
- Viridian Acquisitions LLC
- Facility type
- Data center, AI use likely
- Location
- Janesville, Rock County, WI
- Coordinates
- 42.6633, -89.0206 (approximate)
- Power capacity
- 800 MW planned
- Land
- 250 acres
- Investment
- $8 billion
- Announced
- November 2025
- Utility
- Not established from a public source
- Cooling
- Not established from a public source
- Water use
- Not established from a public source
- Jobs
- 600 permanent; 1,200 construction
- Public subsidy
- Not established from a public source
- Community reception
- Contested
- Source confidence
- Confirmed by multiple independent sources or official documentation
Timeline from the record
Newest first. Record entries come from the filings and reports the registry cites. Coverage entries are headlines from publisher feeds we monitor daily, linked to the outlet; last checked September 14, 2026.
- November 11, 2025ProposedJanesville City Council voted 5-2 to approve a non-binding letter of intent, opening a 120-day negotiation window with Viridian. Source: Wisconsin Public Radio
Opposition and litigation at this site
Yes. APECS Data Center Campus (Former GM Assembly Plant) in Janesville, Rock County, Wisconsin is contested. Hearings, public comment, petitions, or organized opposition are on record, and no lawsuit has been filed so far. More than 20 residents spoke against the proposal at the November 2025 council meeting; a Nov.
How the community has taken it
Reception is a sourced signal, not an editorial judgment: contested means active public debate is on record, with hearings, petitions, or organized opposition, without litigation.
More than 20 residents spoke against the proposal at the November 2025 council meeting; a Nov. 3, 2026 Janesville ballot initiative would require voter approval for projects over $450 million at the GM/JATCO site.
Notes on the record
Redevelopment of the 250-acre former General Motors assembly plant (demolished 2019), a DNR-cleanup brownfield. Two configurations are under evaluation: an 11-building data center campus or an 8- or 9-building hyperscale campus, drawing up to 800 MW. Utility is Alliant Energy. The end user has not been disclosed. Coordinates are the geocoded former GM plant site, not a parcel-confirmed footprint.
What the record does not establish, and the document that would
In every fight on our tracker the decisive fact came out of a public records request. These are the requests for this site.
- Cooling method and water use
- Tax abatements or other public subsidy
- Which utility serves it
Which document closes each gap
- Cooling method and water use
- The water service agreement, any groundwater appropriation permit, and the mechanical narrative in the site plan.
- Tax abatements or other public subsidy
- The abatement, PILOT, or development agreement approved by the county, city, or development authority, and the state's data center sales tax exemption certificate if one was issued.
- Which utility serves it
- The electric service agreement or the utility's filing with the state public utility commission.
Have one of these documents? Send it to us and we will add it to the record with attribution.
Other sites within 30 miles
Distances are between recorded coordinates, many of which are a city or county centroid, so treat them as approximate. Cumulative load on one utility and one aquifer is the question a planning commission rarely asks.
- Project Cornmaze Data Center (Town of Beloit) · Beloit · Cambrin LLC5 mi · Proposed
Questions people ask about this site
Is there opposition to the APECS Data Center Campus (Former GM Assembly Plant) in Janesville?
Yes. APECS Data Center Campus (Former GM Assembly Plant) in Janesville, Rock County, Wisconsin is contested. Hearings, public comment, petitions, or organized opposition are on record, and no lawsuit has been filed so far. More than 20 residents spoke against the proposal at the November 2025 council meeting; a Nov.
Has anyone filed a lawsuit over the APECS Data Center Campus (Former GM Assembly Plant)?
No lawsuit over APECS Data Center Campus (Former GM Assembly Plant) appears in the record we track as of August 18, 2026. Residents most often reach a lawyer over water supply, well drawdown, noise from cooling plant, property value, or a rezoning approved without the notice the ordinance required. If any of that is happening near this site, it is worth a review whether or not a case has been filed yet.
How much water does APECS Data Center Campus (Former GM Assembly Plant) use?
No water withdrawal figure for APECS Data Center Campus (Former GM Assembly Plant) is on record here. Water use is rarely published voluntarily; it usually surfaces through a utility service agreement or a state withdrawal permit, both of which are public records. We leave the number blank rather than estimate one.
Who operates APECS Data Center Campus (Former GM Assembly Plant), and how big is it?
Viridian Acquisitions LLC is the operator on record. Capacity on record is 800 MW. The site is recorded at 250 acres.
How to cite this page
SueDataCenters.org Data Center Registry, "APECS Data Center Campus (Former GM Assembly Plant)," updated August 18, 2026, https://suedatacenters.org/data-centers/viridian-apecs-janesville-wi.
Facility data from Compute Atlas (E. Kubiak), version 1.32.0 (September 7, 2026), licensed CC BY 4.0, record https://www.compute-atlas.com/facilities/viridian-apecs-janesville-wi, retrieved September 14, 2026.
Corrections with a public source are welcome at the Compute Atlas record or through our contact page. The whole registry is available as CSV and JSON under CC BY 4.0.
Sources for this record
As compiled and cited by Compute Atlas, with our own reporting appended. Archived links are used where the original has moved.
- 1.Janesville moves forward with data center plans for abandoned GM site · Wisconsin Public Radio · retrieved August 18, 2026
- 2.APECS Data Center Campus, project record · Baxtel · retrieved August 18, 2026
- 3.The Rock County data center fight: Janesville's three proposals · 608 Scanner · retrieved August 18, 2026
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