Viridian Data Center Campus (former GM/JATCO site)
Janesville, Rock County, WIDeveloper: Viridian
- Rumored
- Proposed
- Approved
- Under construction
- Operating
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Colorado-based Viridian proposed buying and cleaning up the former General Motors assembly plant site in Janesville, Wisconsin, and converting it into an 11-building, 800-megawatt data center campus with an investment of over $8 billion. The city council approved a letter of intent 5-2 in November 2025, but in June 2026 the council voted not to extend it, taking the data center off the table.
- Planned capacity
- 800 MW[1]
- Permanent jobs (promised)
- 600
- roughly 600, per Viridian estimates
Key facts
Size & schedule
| Planned capacity | 800 MW [1]Source excerpt“The project is expected to need up to 800 megawatts of power.” |
|---|---|
| Site size | 250 acres [1] roughly 250-acre site Source excerpt“The letter of intent, with Colorado-based Viridian Acquisitions LLC, is the first step towards a project going up on the roughly 250-acre site.” |
| Buildings | 11 [2]Source excerpt“The site would then be converted to an 11-building, 800 megawatt data center campus.” |
| Stated investment | Over $8 billion [1] over $8 billion, per Viridian Source excerpt“Erik Zitek, the director of development for Viridian, said the total investment in the campus would be over $8 billion.” |
| Permanent jobs (promised) | 600 [2] roughly 600, per Viridian estimates Source excerpt“The project has won the backing of the local chapter of the International Brotherhood of Electrical Workers thanks to Viridian's estimates that it would create roughly 600 permanent jobs, as well as 13,000 jobs during construction.” |
| Construction jobs | 1,200 [1] Viridian estimate, as reported by WPR Source excerpt“He said the project could create 1,200 construction jobs and the campus could employ 600 people.” |
How big is that? Data center sizes compared with football fields and Central Park.
Power
| Utility | Alliant Energy [2] Utility pages: Alliant Energy · data centers and bills new substation with Alliant and American Transmission Company, per proposal Source excerpt“Viridian and its development partner, Virginia-based Abbleby Strategy Group, would work with Alliant Energy and American Transmission Company to develop a new electrical substation for grid interconnection” |
|---|
Local decisions & site
| Deciding vote | Janesville City Council approved the letter of intent 5-2 (November 2025) [1]Source excerpt“The council voted 5-2 to approve the letter of intent.” |
|---|
Figures are as stated by the cited source. Where sources disagree, each figure is shown.
Water and power
Water
Not disclosed. No source reviewed gives a water figure for this site. The Census does not estimate one.
Disclosed figures only, each as the cited source states it. Many are projections or permit limits, not metered use. How data center water and power use is measured, and every disclosed figure →
Timeline
City of Janesville begins discussions with Viridian Partners on redeveloping the former GM site [3]
Janesville City Council approves a letter of intent with Viridian 5-2 [1]
City Council places a citizen initiative requiring voter approval for projects over $450 million at the GM/JATCO site on the Nov. 3, 2026 ballot [4]
City Council votes not to extend the letter of intent with Viridian [5]
Issues raised
- The site requires remediation of contaminated soil, a cleanup estimated at $30 million [2]
- A citizen initiative on the Nov. 3, 2026 ballot would require voter approval for development over $450 million on undeveloped portions of the GM/JATCO site [4]
Issues are concerns and claims raised by the parties, officials or residents named in the cited sources. They are reported as attributed, not as findings by the Census.
Sources
- Janesville moves forward with data center plans for abandoned GM siteWPR · Nov 11, 2025 · news
- No one wanted to redevelop this polluted property. Then came AI.E&E News by POLITICO · Mar 30, 2026 · news
- Records: City of Janesville, developer launched talks on GM site data center in mid-2024The Gazette (gazettextra.com) · May 14, 2026 · news
- Janesville, Wisconsin, voters to decide Nov. 3, 2026, initiative requiring approval for development projects exceeding $450 million at GM/JATCO site, such as proposed data centerBallotpedia News · Feb 12, 2026 · news
- Janesville seeks public input on former GM/JATCO site redevelopmentWMTV 15 News · Jun 26, 2026 · news
Cite this page
Last updated Sep 22, 2026. Figures may change as records are updated — include the date you retrieved them.
| APA | Data Center Census. (2026). Viridian Data Center Campus (former GM/JATCO site). Retrieved from https://datacentercensus.com/dc/viridian-gm-site-janesville-wi |
|---|---|
| MLA | “Viridian Data Center Campus (former GM/JATCO site).” Data Center Census, Sep 22, 2026, https://datacentercensus.com/dc/viridian-gm-site-janesville-wi. |
| Link | https://datacentercensus.com/dc/viridian-gm-site-janesville-wi |
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