FieldProspects

Jefferson County, Wisconsin

Jefferson County, Wisconsin has 25 power projects in the FieldProspects database: 19 operating plants totaling 759.8 MW and 6 planned projects totaling 653 MW. No data center record lists the county. Solar leads with 741.3 MW across 11 projects. 2 planned projects are past their listed in-service date.

Data as of Grid region: Midcontinent ISO (MISO)Refreshed monthly
25
power projects, planned and operating
653MW
planned generation, 6 projects
759.8MW
operating generation, 19 projects
2
planned projects past their listed in-service date
Map

Jefferson County and its neighbors

Counties shaded by data center MW on record, planned to operating. 4 of its 5 neighboring counties have pages of their own. The rest are in the member database.

Waukesha Rock 800 MW Dodge 197.6 MW Dane 1.3 MW Walworth no data centers Jefferson no data centers
no data center MWunder 100 MW100 to 1,000 MW1,000 to 5,000 MW5,000 to 15,000 MW15,000 MW or more no page yet

Data center records planned, under construction and operating, data as of October 8, 2026.Hover a county for its numbers

Headline finding
86%

of the county's operating generation is in the queue as new capacity: 653 MW planned across 6 projects against 759.8 MW operating, 2 of the planned projects already late.

Operating generation759.8 MW
Planned generation653 MW

Technology mix

25 projects, 1.4 GW planned and operating

Solar741.3 MW11 projects, 52%
Natural Gas665.1 MW6 projects, 47%
Landfill Gas6.4 MW8 projects, 0%
Which companies own these 25 projects?Project names, developers and contacts are for members.See what members get

Power generation in the county

19 plants operate inside Jefferson County, 759.8 MW. The queue adds 653 MW across 6 projects, and 2 of them are past their listed in-service date.

Figure 1

Operating and planned generation by technology

MW in Jefferson County

OperatingPlanned
SolarOperating 88.3 MW 5 projects
SolarPlanned 653 MW 6 projects
Natural GasOperating 665.1 MW 6 projects
Landfill GasOperating 6.4 MW 8 projects
View as table
TechnologyStatusProjectsMW
SolarOperating588.3
SolarPlanned6653
Natural GasOperating6665.1
Landfill GasOperating86.4
Operating: 759.8 MW. Planned: 653 MW. If every planned project is built, county generation would reach 1.4 GW.
Source. FieldProspects database: ISO/RTO interconnection queues, EIA-860M and public data center filings, data as of October 8, 2026.
Figure 2

Planned generation by listed in-service year

MW. Years before 2026 are past due.

Past dueDue 2026 or later
0100200300 Snapshot year 149 2022 75 2023 2024 2025 2026 149 2027 280 2028
View as table
YearPlanned projectsMW
20221149
2023175
202400
202500
202600
20271149
20283280
2 projects, 224 MW, were due before 2026

Jefferson County against its neighbors

Rock County has the most data center MW among the neighbors, 800 MW. 4 of the 4 have more generation operating than data center MW on record.

CountyData center recordsData center MWOperating generation MWPlanned generation MWData center MW per MW operating
Rock County 1
800
1,829
1,228 0.44x
Dodge County 2
198
337
175 0.59x
Dane County 1
1
1,172
2,614 0x
Jefferson County this page 0
0
760
653 0x
Walworth County 0
0
26
1,948 0x

Data center MW counts records planned, under construction and operating. Generation is inside the county only. Neighbors without a page have fewer than three projects on record.

5 counties shown

What changed since June 4, 2026

3 projects in Jefferson County moved between the two snapshots. Counts and MW are below; the projects themselves are for members.

Open the change feed
0
added to a queue, 0 MW
2
came online, started construction or signed an interconnection agreement, 298 MW
0
cancelled, dropped or went inactive, 0 MW
1
slipped its in-service date, 149 MW

Every change in Jefferson County

Project, what changed, technology, MW and the dates that moved, for all 3 changes.

Members only
County: Jefferson County, WISince June 4, 2026 3 changes
ProjectChangeTechnologyMWPrevious dateNew date
3 changes behind this preview

Rows are hidden on public pages. Members see the project behind each change, its developer and the dates that moved.

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Every record in Jefferson County

Project name, developer, status, MW, in-service year and the developer’s contacts, for all 25 records. Filter, sort and export to Excel.

Members only
County: Jefferson County, WIStatus: all except cancelledSort: MW, largest first 25 records
Project or campusDeveloperStatusMWYearContacts
25 records and 1.4 GW behind this preview

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