Larimer commissioners continue decision on Platte River’s request for five aeroderivative turbines at Rawhide

Platte River Power Authority asked the Larimer County Board of County Commissioners on March 10 to approve a 10‑41 permit to install five aeroderivative natural‑gas turbines and supporting infrastructure at the Rawhide Energy Station; the board continued the hearing to March 24 to allow more technical review and community input.

The application covers about 30 acres of new construction with roughly 32 additional acres set aside for laydown and staging on PRPA’s Rawhide site, located about 9 miles north of Wellington on County Road 82. Cassidy Fiore, principal planner for Larimer County, told commissioners the application was accompanied by an extensive packet of technical reports, that staff and referral agencies had proposed 32 recommended conditions of approval, and that the county had asked the applicant for follow‑up materials during the technical review.

Why it matters: Commissioners, staff and residents framed the decision around two competing obligations — meeting grid reliability and decarbonization goals while protecting public health in a region designated a severe ozone nonattainment area. The hearing drew more than 40 people for public comment and a sustained technical presentation from county planners, health staff and PRPA.

Staff and health analysis: Leah Schneider of Larimer County Health and Environment summarized air‑quality review and permitting steps. Schneider said the Colorado Air Pollution Control Division reviewed PRPA’s air modeling and found the applicant’s dispersion modeling to be satisfactory and that, in the division’s review to date, the proposed project would not cause a modeled violation of EPA’s National Ambient Air Quality Standards. Schneider noted the applicant initially modeled six turbines for permitting but told the county the proposal before the board is five; she and county staff said they had asked the state air regulator for a full construction permit and are coordinating that technical review. Schneider noted that the ozone nonattainment area is driven primarily by emissions from sources in Weld County and by regional meteorology, but said local reductions remain important to meeting the federally required standard.

Applicant presentation and technical points: Matt Tribby, representing Platte River Power Authority, said the proposed turbines are “aeroderivative” machines — jet‑engine‑based units the utility proposes to use as fast‑starting, dispatchable backup to accommodate more wind and solar. PRPA said the turbines would complement a planned expansion of renewables and enable the utility to retire one coal unit at Rawhide by the end of the decade; PRPA representatives said construction could start in 2026 with operations in 2028 and that the utility had evaluated alternatives, including batteries and long‑duration storage.

Public comment and controversy: Speakers were split. Many residents and regional environmental groups urged denial or a pause, saying PRPA had not shown the proposed turbines are necessary and raised concerns about ozone precursors, greenhouse gases and the applicant’s refusal to allow an independent third‑party review of its integrated resource plan. Tom Moore of the Regional Air Quality Council said, “we really need all possible local emission reductions” to meet the 2026 attainment planning targets. Other speakers, including elected leaders from PRPA owner communities, supported the project as the most feasible path to retire coal while preserving reliability and keeping rates manageable.

Board action: After a brief executive session to consult the county attorney, the board voted to continue the public hearing to March 24, 2025, at 3:00 p.m. Commissioners asked the applicant and county staff to provide additional information focused on the 10‑41 review criteria for alternatives (criteria C), environmental mitigation (criteria E), and the project purpose/need (criteria D) as they relate to power‑plant‑specific rules. PRPA agreed to the continuance and said it would provide requested follow‑up materials.

What’s next: The county will accept additional technical materials in advance of the resumed hearing. County staff and referral agencies indicated they will continue technical review, the Colorado Air Pollution Control Division will complete its permitting review, and commissioners said they want clearer documentation tying PRPA’s resource decisions to alternatives analysis, emissions modeling and the claimed path to renewable integration.

Ending: The board set the continued hearing for March 24, 2025, and left the record open for the supplemental technical material requested by commissioners.