Linn County planners continue drafting rules for commercial battery energy storage, defer final decisions on mid-size projects

Linn County Planning and Zoning commissioners spent the bulk of their meeting reviewing a draft ordinance to govern commercial battery energy storage systems (BESS), focusing on which sizes of systems the county should regulate, setbacks and operational buffers, emergency-response requirements, decommissioning bonds and soil testing, and permit procedures.

Commissioners and staff said the immediate goal is to finalize rules for tier 2 and tier 3 commercial systems and leave smaller residential systems (tier 1) out of the new county regulations. County staff explained the draft ties into existing zoning and the county’s comprehensive plan and would be implemented through conditional use permits subject to site-plan review and public hearings.

Why it matters: commercial BESS installations can be large — measured in megawatt-hours — and raise concerns about noise, visual impacts, hazardous materials and emergency response. The commission’s rules will determine where operators may locate systems, what safety documentation they must provide, and what financial assurances are required before a system is built.

Most of the discussion addressed definitions and tiers. Commissioners and staff described a three-tier system used in the draft: tier 1 for small, typically residential systems (an aggregate energy capacity up to roughly 80 kilowatts), tier 2 for mid-size commercial systems (roughly 81–600 kilowatts in the draft’s working numbers), and tier 3 for utility-scale systems above about 600 kilowatts. Commissioners noted commercial projects commonly measure in megawatt-hours, and a commercial installation of 50–150 megawatt-hours would typically occupy multiple acres.

On applicability and zoning, the commission agreed to focus the ordinance on tier 2 and tier 3 systems. Commissioners discussed allowable zoning districts and generally favored limiting tier 3 systems to industrial and agricultural districts rather than residential or general countryside zoning. They asked staff to produce clearer language about whether “countryside” zoning should allow tier 2 projects and requested a visual aid showing typical tier‑2 footprints before making a final decision.

Setbacks, buffers and operational footprint were a major topic. Commissioners proposed and debated several distances: a property-line setback for the operational facility (fence and equipment) the commission discussed moving from 200 feet to 500 feet in draft language; dwelling setbacks of up to 1,000 feet from battery containers were suggested to protect nonparticipating neighbors; and environmental setbacks (wetlands, floodplains, sensitive habitats) of 500 feet were proposed. Commissioners emphasized the need to clarify whether setbacks apply to the fence line, the container footprint, or the “operational equipment” (transformers, inverters and interconnection hardware) and directed staff to rewrite the relevant passages so the code language is precise.

On site layout and equipment, commissioners and a consultant discussed the common use of shipping‑container style battery enclosures. Participants said containers are typically 20‑ or 40‑foot shipping containers, usually 8–10 feet tall; one participant estimated a container can represent multiple megawatts depending on manufacturer and battery technology, and the group recommended relying on manufacturer-specified spacing and clearance in the permit conditions.

Emergency response, hazardous materials and training drew repeated attention. Commissioners asked that any CUP require applicants to provide material safety data sheets for on-site chemicals and to post them at the facility entrance for local emergency services. The commission also asked that companies fund and provide training for local fire and EMS personnel tailored to the battery chemistry and fire‑suppression protocol the operator will use. The commission instructed that training must be documented and tied to permit approval.

Decommissioning and financial assurance were flagged as essential. Commissioners asked staff to require a decommissioning plan and a bond set at a percentage above the expected decommissioning cost (one commissioner suggested 125%) that is registered to the county and not available for other claims. They said soil testing should be performed before any ground disturbance and again after decommissioning to document contamination or remediation needs.

Other technical and operational items discussed included: maximum project site size (the draft proposed a 20‑acre limit for a single BESS site, not including separate substations), signage (placard size and spacing around the perimeter), exterior lighting limits (LED color temperature not to exceed 3,000 K was proposed to reduce light pollution), noise limits (the draft referenced decibel limits and comparisons), and limits on structure heights for container enclosures (the commission discussed 15 feet for battery housings and a higher, separate cap for transformer or substation structures).

Process and next steps: commissioners agreed to remove tier‑1 residential language from the draft, to hold off on finalizing tier‑2 numeric standards until they had a clearer example/visual, and to circulate revisions to the draft by email so members can submit targeted edits ahead of the next meeting. Several commissioners asked staff to add explicit references tying the ordinance to the county comprehensive plan’s goals to preserve natural beauty and open space and to require an impact study and environmental reviews as part of the CUP packet.

No final vote on the ordinance occurred. Staff was directed to prepare a revised draft that clarifies setbacks (operational equipment vs. fence line), cleans up references to other counties in copied template text, and includes clearer, numbered CUP submittal requirements (decommissioning plan, bond, interconnection/PPA documentation if applicable, soil sampling, emergency training documentation). The commission also agreed to gather more data about typical container spacing, per‑acre density and equipment footprints and asked staff to return the item after those clarifications are incorporated.

Looking ahead, the commission expects another review cycle after staff issues revision numbers and commissioners provide written comments by email. If the commission forwards a version to a public hearing, the county ordinance process will require public-notice timing consistent with county code (discussed as a 20‑day notice window plus any additional waiting periods at the county commission stage).