Solar Farms and Leasing Land for Solar in Warren County, Missouri

The Split-Rail project: how the county got its first big solar farm

Warren County created its Solar Energy (Solar Farm) Overlay District (SOD) process by amending its zoning code on October 8, 2020, making commercial solar facilities a permitted use within Agricultural zoning districts once an SOD is formally approved over the site. Barely two months later, on December 22, 2020, the County Commission approved the boundaries for the Split-Rail solar energy district -- an irregularly shaped area exceeding 4,400 acres, assembled from more than 30 separate properties between Highway A and Highway W, rated at 300 megawatts of generating capacity. Developer Invenergy built the project; rather than constructing its own facility, Amazon agreed to purchase power from Split-Rail, a common renewable-energy procurement structure for large corporate buyers. The project reached its commercial operations date on June 1, 2026 and substantial completion by June 30, 2026, with ownership transferring from Invenergy to utility Ameren around that time -- reported as roughly $34 million in economic investment for the county.

It's worth being precise about what that 4,400-plus-acre figure means: it's the boundary of the solar energy overlay district assembled across dozens of separate parcels, not necessarily the footprint actually covered by panels, racking, and access roads on every acre within it. If you're evaluating a specific parcel near the district, ask directly whether that parcel is inside the overlay boundary, and if so, what portion of it is under an actual solar lease versus simply within the district's outer boundary.

The 2022 cap: why new solar farms here look nothing like Split-Rail

In 2022, Warren County amended its solar ordinance to cap the size of any new solar farm at 150 acres -- a fraction of the footprint that produced the Split-Rail district. The ordinance also sets specific setback requirements: solar panels within an overlay district must sit at least 200 feet back from non-participating properties (land not part of the lease), and larger-scale solar farms must maintain a 150-foot setback from residences, churches, schools, and businesses. Panels must be built and oriented to minimize glare onto adjacent properties, roadways, and airspace. The ordinance also requires a decommissioning plan, making the project's owner responsible for removing all equipment and restoring the property "as nearly as practicable" to its prior condition when the facility's operating life ends -- a provision worth asking about directly if you're the one leasing land, since it determines who bears the cost of removal decades from now.

The cap has held despite pressure to loosen it: in July 2026, after a public hearing on proposed text amendments that would have permitted larger-scale solar projects under conditions like stricter buffers and decommissioning requirements, the County Commission voted unanimously to reject those amendments and keep the existing 150-acre limit. That's a meaningful signal for anyone weighing a lease offer today -- the county has recently and deliberately chosen not to make it easier to replicate a Split-Rail-scale project, so a new proposal on your land (or a neighbor's) is far more likely to look like a 150-acre installation than a several-thousand-acre district.

What to ask before signing a solar lease, or buying near an existing one

1. Confirm your land's zoning district with Warren County Planning and Zoning ((636) 456-3044) -- a Solar Farm Overlay District can only be layered onto Agricultural-zoned land, so land in a different district would need a rezoning before any solar project could proceed.
2. Ask whether a proposed project is seeking approval under the current 150-acre cap, and get the exact acreage and boundary of the proposed overlay district in writing rather than relying on a developer's verbal description.
3. If you're the landowner considering a lease, ask specifically about the decommissioning plan required by county ordinance -- who is financially responsible for removal and site restoration, and whether that obligation is backed by a bond or other financial assurance.
4. If you're buying near an existing or proposed solar district, confirm the setback distances (200 feet from non-participating property lines, 150 feet from residences/churches/schools/businesses for larger farms) actually being applied to the parcel closest to you, and ask the county whether any glare, drainage, or access-road studies were part of that project's approval.
5. Remember that Warren County's fast growth as a St. Louis exurb means agricultural land near the interstate corridor may face competing pressure from residential subdivision development as well as solar leasing -- factor both possibilities into a long-term view of a specific parcel's surroundings.