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Mason 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 Mason County, county seat Havana.
Check land in Mason 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 Mason County?
The MISO interconnection queue lists 6 proposed projects in Mason County (3 solar, 3 wind), about 1,100 MW in all. 1 has a signed interconnection agreement.
What stands out in Mason County
By capacity, solar leads in Mason County with 642 MW across 3 projects, followed by wind (3 projects, 458 MW). The largest is queue number J2603, a 320 MW solar request in the MISO queue, in study (Phase 2), filed Sep 2022, with a target in-service date of Jun 2026. Of the 6, 5 are 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 Apr 2024. Target in-service dates for those not yet under construction span Apr 2022 to Oct 2028; 5 of them have 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the table: the queue number is the operator's ID for the request (MISO J-numbers, PJM AE/AF/AG-numbers); operators do not publish developer names in these files.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. 5 target in-service dates below have 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. |
|---|---|---|---|---|---|
| J1454MISO · Ameren Illinois · Mason 138 kV Substation | Wind | 58 | Agreement signed | Apr 2019 | Apr 2022 date passed; status per the operator |
| J2603MISO · · 4PURO - 4HAVANA3 138.0kV | Solar | 320 | In study (Phase 2) | Sep 2022 | Jun 2026 date passed; status per the operator |
| J2963MISO · · Puro | Wind | 200 | In study (Phase 2) | Sep 2022 | Oct 2025 date passed; status per the operator |
| J3519MISO · Ameren Illinois · Quiver | Wind | 200 | In study (Phase 2) | Apr 2024 | Oct 2028 |
| J3003MISO · · 4HAVANA2 - 4CINCINATTI 138.0kV | Solar | 180 | In study (Phase 2) | Sep 2022 | Aug 2025 date passed; status per the operator |
| J3004MISO · · Cane | Solar | 142 | In study (Phase 2) | Sep 2022 | Aug 2025 date passed; status per the operator |
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 Mason County require of a project?
Illinois law sets the ceiling: Mason 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: On March 12, 2024 the Mason County Board approved Resolution 2024-19 adopting a Battery Energy Storage System (BESS) Siting Ordinance, Resolution 2024-20 approving text amendments to the Commercial Solar Energy Facility Siting Ordinance, and Resolution 2024-21 approving text amendments to the Commercial Wind Energy Facility Siting Ordinance. The minutes record each motion as carried without a vote tally. (Mason County Board minutes, March 12, 2024)
State siting standardsFarmland agreement (AIMA)Property taxes
Who to contact in Mason 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 Havana. A drainage district, if the land is in one, must receive the developer's drainage plan.
Mason County websiteCounty engineer and highways
Solar for homes and businesses in Mason 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 Mason 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).