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Washington 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 Washington County, county seat Nashville.
Check land in Washington 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 Washington County?
The MISO interconnection queue lists 5 proposed projects in Washington County (2 solar, 1 solar plus storage, 2 battery storage), about 1,235 MW in all. 2 have a signed interconnection agreement.
What stands out in Washington County
By capacity, solar paired with storage leads in Washington County with 500 MW across 1 project, followed by solar (2 projects, 400 MW) and battery storage (2 projects, 335 MW). The largest is queue number J2690, a 500 MW solar paired with storage request in the MISO queue, in study (Phase 2), filed Sep 2022, with a target in-service date of Apr 2027. Of the 5, 3 are still in study, 1 has a signed agreement and 1 is under construction. All of them are in the MISO queue, which covers the Ameren Illinois side of the state. The requests were filed between Mar 2018 and Nov 2025. Target in-service dates for those not yet under construction span Oct 2023 to Sep 2028; 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the table: the queue number is the operator's ID for the request (MISO J-numbers, PJM AE/AF/AG-numbers); operators do not publish developer names in these files.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. |
|---|---|---|---|---|---|
| J1094MISO · Ameren Illinois · Prest 138kV Switching Station | Solar | 150 | Under construction | Mar 2018 | Jan 2021 |
| J1216MISO · Ameren Illinois · Ashley 138 kV Substation | Solar | 250 | Agreement signed | Apr 2019 | Oct 2023 date passed; status per the operator |
| J2690MISO · · Other_ | Solar + storage | 500 | In study (Phase 2) | Sep 2022 | Apr 2027 |
| J3316MISO · Ameren Illinois · Okawville 138 kV | Storage | 150 | In study (Phase 2) | May 2024 | Sep 2028 |
| R5087MISO · · 4JORD - 4ASHLEY 138.0kV | Storage | 185 | In study | Nov 2025 | Jun 2027 |
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 Washington County require of a project?
Illinois law sets the ceiling: Washington 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.
Recent local action: The Washington County Zoning Board of Appeals posted an agenda for a March 26, 2026 hearing on two special use permit requests from Wild Cat Solar 30, LLC and Wild Cat Solar 32, LLC (New Energy Equity) for commercial solar energy facilities, including a 5.0 MWac facility at 10102 State Route 127, Nashville. (Washington County ZBA agenda, March 26, 2026)
State siting standardsFarmland agreement (AIMA)Property taxes
Who to contact in Washington 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 Nashville. A drainage district, if the land is in one, must receive the developer's drainage plan.
Washington County websiteSupervisor of assessmentsZoning and planningCounty engineer and highways
Solar for homes and businesses in Washington 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 Washington 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).