A provision in Oklahoma's SB237 eliminates a major tax break for manufacturers who own or operate battery storage systems.
Most Oklahoma manufacturers don't realize that a provision buried in SB237 could cost them thousands in property taxes over five years—and it takes effect November 1, 2026.
Here's what changed: Oklahoma law has long offered a 5-year ad valorem tax exemption for qualifying manufacturing facilities. This exemption eliminates property tax liability on equipment and real property used in manufacturing operations. It's a significant benefit for capital-intensive businesses.
SB237 narrows that exemption. Starting November 1, 2026, battery energy storage systems are explicitly excluded from the exemption. This means if your manufacturing operation includes a large-scale interconnected battery system that stores electrical energy—whether for backup power, load management, or grid services—you cannot claim the 5-year tax break on that asset.
The exclusion applies to small and mid-sized manufacturers that own or operate battery storage systems. This includes:
• Facilities using battery systems for backup power during outages
• Operations with battery-based load management or peak-shaving systems
• Manufacturers participating in grid services or demand response programs
• Any business with a large-scale interconnected battery energy storage system on-site
If your facility doesn't use battery storage, this provision doesn't affect you.
The impact depends on the value of your battery system and your local mill levy. A $500,000 battery installation in a county with a 10 mill rate would generate roughly $5,000 in annual property tax liability—for five years, that's $25,000 in taxes you cannot avoid through this exemption.
For manufacturers considering battery storage investments, this exclusion should factor into your return-on-investment calculations.
The exclusion is codified in Section 1 of SB237, which amends Section 2902(B)(1) of Oklahoma law. The effective date is November 1, 2026, giving businesses roughly two years to plan.
The bill defines battery energy storage systems as large-scale interconnected systems designed to store electrical energy. The definition is broad enough to cover most commercial and industrial battery installations.
If you operate or plan to install battery storage, review the timeline. Installations completed before November 1, 2026, may still qualify for the exemption under the old rules—though you should verify this with your county assessor and a tax professional, as implementation details may vary by jurisdiction.
If you're evaluating battery storage as a capital investment, factor the full five-year property tax cost into your analysis. The exemption you might have counted on is no longer available.
Contact your county assessor's office with questions about how this applies to your specific facility, or consult a tax advisor familiar with Oklahoma manufacturing incentives.
Source: Oklahoma SB237, Section 1 (amending Section 2902(B)(1)), effective November 1, 2026.