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Jefferson County, Illinois: solar, wind, and storage projects and permits
Proposed projects, county offices, and the state rules for a solar, wind, or battery storage project in Jefferson County, county seat Mount Vernon.
Check land in Jefferson CountyOpens the land report with the map on the county; click a spot for its flood, wetland, habitat, line-distance and parcel check.
What energy projects are proposed in Jefferson County?
The MISO interconnection queue lists 2 proposed projects in Jefferson County (1 solar, 1 battery storage), about 400 MW in all. 1 has a signed interconnection agreement.
What stands out in Jefferson County
By capacity, solar leads in Jefferson County with 200 MW across 1 project, followed by battery storage (1 project, 200 MW). The largest is queue number J1241, a 200 MW solar request in the MISO queue, agreement signed, filed Apr 2019, with a target in-service date of Sep 2022. Of the 2, 1 is still in study and 1 has a signed agreement. All of them are in the MISO queue, which covers the Ameren Illinois side of the state. The requests were filed between Apr 2019 and Sep 2022. Target in-service dates for those not yet under construction span Sep 2022 to Oct 2026; 1 of them has already passed, which means those schedules slipped.
A listing means a developer asked the grid operator to study connecting a project; many are never built, and the status column says where each one stands.
Reading the table: the queue number is the operator's ID for the request (MISO J-numbers, PJM AE/AF/AG-numbers); operators do not publish developer names in these files. Connection is the transmission owner and, where listed, the substation or line; "Other_" is the operator's own placeholder. In study (Phase 1/2) are MISO's definitive-planning study phases; "moved to TC1" means a PJM request was carried into Transition Cycle 1; "CIR Increase" is a request to add capacity rights to an existing project; "LRTP" names a MISO long-range transmission project. For PJM rows, MW is the figure in the megawatt column of PJM's public queue export; PJM also tracks maximum facility output and capacity rights separately, so a project's study documents can show a different number. 1 target in-service date below has already passed while the request is still open: operators keep the developer's last reported date until the developer changes it, so a past date means the schedule slipped, not that the project was built.
Scroll the table sideways to see every column.
| Queue number and connection | Type | MW | Stage | Requested | Target in-service iThe in-service date the developer gave the grid operator. Developers set and change it, many projects slip, and some are never built. |
|---|---|---|---|---|---|
| J1241MISO · Ameren Illinois · West Mt Vernon - Xenia 345kV Line | Solar | 200 | Agreement signed | Apr 2019 | Sep 2022 date passed; status per the operator |
| J3031MISO · Ameren Illinois · 4WLTNVL TP 138 kV | Storage | 200 | In study (Phase 2) | Sep 2022 | Oct 2026 |
Sources: MISO generator interconnection queue and PJM interconnection queue, downloaded October 7, 2026; withdrawn and operating projects are left out, and the operators do not publish developer names. What the stages mean.
What can Jefferson County require of a project?
Illinois law sets the ceiling: Jefferson County must approve a commercial wind or solar project that meets the state standards, must finish its public hearing within 60 days, and may not ban them in agricultural or industrial zones (55 ILCS 5/5-12020); battery storage has had its own statewide standards since June 1, 2026 (55 ILCS 5/5-12024). Land inside a city or village falls under municipal zoning instead.
State siting standardsFarmland agreement (AIMA)Property taxes
Who to contact in Jefferson County
Assessment questions go to the supervisor of assessments, special use applications to the zoning office, and road use agreements to the county engineer; the county seat is Mount Vernon. A drainage district, if the land is in one, must receive the developer's drainage plan.
Jefferson County websiteSupervisor of assessmentsCounty engineer and highways
Solar for homes and businesses in Jefferson County
Illinois net metering, the Illinois Shines incentive, and HOA rules are the same statewide; Ameren Illinois sets the application steps here: Illinois home and business solar rules · utility application links.
State and federal reviews
Illinois EPA stormwater coverage, IDNR's EcoCAT review, historic preservation review, and federal wildlife screening can apply to a site in Jefferson County: Illinois agency list.
Get the land report for a spot
Flood zone, wetlands, nearest power line, soils, and more for any point. Parcel acreage fills in automatically in Texas and 26 other states (not Illinois, which has no statewide parcel layer).