Santa Fe Planning Commission hears Rancho Viejo 96 MW solar and 48 MW/4‑hour battery storage proposal amid safety, water and land‑use debate

The Santa Fe County Planning Commission on Feb. 20 heard a multi‑hour presentation and cross‑examination of Rancho Viejo Solar LLC’s application for a conditional‑use permit to build a 96‑megawatt solar facility and a 48‑megawatt, four‑hour battery energy storage system (about 192 megawatt‑hours) on an 828‑acre, rural‑fringe parcel. County staff recommended the Planning Commission approve the CUP with 19 conditions, but the hearing produced extensive technical discussion of battery safety and wildfire risk and robust public comment both for and against the project.

The project would be sited on a private parcel addressed off State Road 14 about three miles south of the Santa Fe city limits. AES Clean Energy Development LLC is the applicant and Rancho Viejo Solar LLC is the project company. County staff told the commission the site plan calls for about 684 acres of the parcel to be developed with the solar arrays and ancillary facilities; the applicant has proposed a decommissioning bond and an application to remove development rights on surrounding acreage.

Why it matters: Santa Fe County and the state of New Mexico have formal climate and energy goals and the investor‑owned utility PNM is seeking clean resources. The project would add a sizable amount of solar and battery capacity to PNM’s portfolio; supporters say it will help meet mandated renewable targets and produce construction jobs and local economic activity. Opponents say the combination of lithium‑ion batteries and the site’s proximity to residential neighborhoods, schools and shallow wells creates unacceptable public‑safety, wildfire and property‑value risks.

What staff told the commission

County Growth Management Director Alexandra Ladd opened the staff presentation, stressing the roles of county staff, the hearing officer and the Planning Commission in the quasi‑judicial CUP process. Ladd summarized recent legal and policy changes the county considered while reviewing the application, including the 2021 New Mexico Community Solar Act and the Public Regulation Commission’s implementing rule adopted March 30, 2022, and a 2022 county resolution expressing Board policy interest in community solar on public land. She noted the county adopted NFPA 855‑based fire code changes in 2023 and that staff had worked with outside consultants.

Dominic Cisneros, the county’s case planner, outlined the application details and the staff findings: the project parcel is zoned rural‑fringe; Appendix B of the Sustainable Land Development Code allows commercial solar as a conditional use in that district; staff found the CUP submittal complete and recommended approval subject to 19 conditions the commission would record if it approved the CUP. Cisneros said access would be from State Road 14, that about 684 acres would be developed, and that the applicant has proposed transfer‑of‑development‑rights (TDR) applications to protect surrounding agricultural uses. He clarified that the nearest residence to the proposed battery energy storage (BES) yard is between 1 and 2 miles away (the staff GIS maps initially showed shorter distances to parcel boundaries but greater distances to the BES location itself).

Third‑party fire review and county fire position

Santa Fe County retained Atar Fire for an independent, third‑party review of the battery storage design and documentation. Atar Fire principal Nick Bartlett and consultant Todd Laberge summarized what they had reviewed: the hazard mitigation analysis, UL 9540A test reports, a draft UL‑style listing report, explosion/deflagration modeling and a full‑scale deflagration test report, the site drawings, and emergency/incident response plans. Bartlett and Laberge emphasized that the county’s code adoption of NFPA 855 (and the IFC) requires objective compliance at construction plan review and that the CUP is a separate, subjective land‑use gate. Bartlett said the Atar review raised clarifying questions and expectations that the applicant must meet before construction permits are issued. He summarized the layered safety approach the review recommends—cell/module design and quality control, battery management and monitoring, gas detection and ventilation, explosion venting (NFPA 68), and a direct‑injection thermal‑runaway propagation suppression system—plus separation and site defensible space. He told the commissioners that “the codes are objective; it’s either pass or fail” at the plan review/fire marshal stage.

What the applicant presented

AES Clean Energy’s Josh Mayer (senior development manager) said the project is sized at 115 MW DC (96 MW AC) of PV plus 48 MW/4‑hour battery storage (about 192 MWh). AES representatives showed a summary of technical testing their suppliers provided, including UL 9540A cell/module/unit/installation tests and a CSA‑documented full‑scale demonstration of the direct‑injection extinguishing approach AES proposes for module‑level thermal‑runaway propagation suppression. AES emphasized multiple layers of mitigation that it says will be applied: distance and separation of containers; sealed, ISO‑style battery enclosures on concrete pads with gravel and perimeter roads to act as firebreaks; gas detection, exhaust ventilation and deflagration venting; module‑level direct‑injection suppressant intended to stop propagation; NFPA‑compliant alarm and monitoring; and operations staffing and remote monitoring. AES said it had also voluntarily proffered a 30,000‑gallon water tank for site defense and had filed for transfer of development rights to conserve much larger areas of adjoining land.

AES also described economic and timing assumptions: a construction period of about a year, roughly 200 construction jobs, ongoing O&M staffing, an anticipated construction budget in the hundreds of millions of dollars and a decommissioning bond estimated by the applicant at roughly $7.6 million (the applicant’s decommissioning plan estimated about $9.6 million gross removal cost before salvage value). AES told the commission it planned to submit bids to PNM later this year and targeted an in‑service window that would meet PNM’s 2029‑2032 needs if selected.

Technical debate at the hearing

At the hearing, the Atar Fire consultants and AES engineers (AES engineer Mike Simpson and others) debated test results, test scope and code application. AES and Atar Fire said the product design under review had been tested to UL 9540A protocols and that CSA had recorded full‑scale tests demonstrating the direct‑injection suppressant’s capability to stop propagation in an affected enclosure; the consultants also stressed NFPA 855 and the IFC require final listing/certification and full compliance at the plan review and construction stage before any certificate of occupancy. Third‑party reviewers noted some documentation clarifications that must be resolved as the design evolves to the construction‑permit phase, and they said some tests are installation‑specific and must be verified for the exact equipment and layout proposed.

Public comment and community objections

More than a dozen community groups and individuals testified. Supporters – including representatives of 350 Santa Fe, the Santa Fe Green Chamber of Commerce, the Clean Energy Coalition and local solar developers – framed the project as a necessary contribution toward state and county renewable targets, a source of construction jobs and local revenue, and a way to expand access to clean energy for customers who cannot install rooftop solar. Several speakers, including developers and supply‑chain contractors, argued large projects must be sited where transmission and access are feasible and that BESS integrated with large PV installations are now common, widely regulated and becoming safer with NFPA standards and UL testing.

Opponents – including local residents, San Marcos neighborhood representatives, New Mexicans for Responsible Renewable Energy and others – raised concerns about wildfire risk, potential off‑site contamination from firefighting runoff or suppressant decomposition products, documented battery fires elsewhere, the sufficiency of the submitted testing and the site’s rural‑fringe zoning. Testimony questioned whether the SLDC’s classification language and the Sustainable Growth Management Plan anticipated utility‑scale solar/BESS in this zoning, disputed the applicant’s property‑value and noise assessments, and urged a county‑wide, DCI‑style review for facilities the size of Rancho Viejo. Speakers asked for additional county conditions including stronger monitoring, indemnity/insurance security, and ongoing public reporting if the CUP is approved.

Staff conditions

Staff recommended approval contingent on 19 conditions that will be recorded with the CUP site development plan if the Planning Commission approves, including: compliance with all reviewing agencies and the 93 conditions imposed by Santa Fe County Fire Prevention; prohibition on drilling or using new wells on the property for the project; permanent fencing and archaeological site protection; permitted and inspected access roads with financial guarantees; monopole transmission structures except where otherwise shown; a life‑of‑project decommissioning bond; renewal of NMDOT access permits; an approved NMED wastewater permit prior to development permit submittal; detailed water budget before recordation of the CUP; smoke and plume modeling for fire‑department review; reimbursement of the county’s third‑party review costs; a 10‑foot noncombustible defensible space within an overall 30‑foot perimeter; limits on construction hours (Mon–Sat 7 a.m.–7 p.m.); and requirements to apply for all applicable development permits after CUP recordation. Staff emphasized the CUP decision does not constitute approval to build; construction permits and compliance with adopted codes and NFPA standards remain required.

Procedural status

The Planning Commission did not take a final land‑use vote at the Feb. 20 hearing. Commissioners accepted the staff presentation, heard applicant testimony and received public comment, then recessed the hearing to continue the proceeding at 1:30 p.m. the following day in the Santa Fe County chambers. Two procedural motions were recorded: the agenda’s approval by roll‑call vote early in the meeting, and a later motion to continue/recess the public hearing to the next day, which passed on a recorded roll call. No final CUP decision was made on Feb. 20.

What to watch next

If the commission resumes deliberations and takes action, the county’s decision either to approve (with recorded conditions) or deny the CUP will be documented in the Planning Commission minutes and any appeals would go to the Board of County Commissioners. Separately, compliance with fire and building codes (including NFPA 855 and UL listing/certification as applicable) remains a precondition to county construction permits; any UL 9540/9540A listing work, final design verification and fire‑marshal signoffs are prerequisites to actual construction. AES also indicated it will continue to refine design details and testing evidence as it pursues utility contracting and final engineering.

The Rancho Viejo proposal illustrates the policy tradeoffs counties face as they evaluate large‑scale renewable projects: community energy and economic benefits on one hand and unresolved technical, safety and land‑use concerns on the other. The Planning Commission’s continuing deliberations will focus on whether the staff‑recommended conditions and the required subsequent technical verifications provide sufficient protection for local public safety, water resources and neighborhood concerns.

Ending note: The Planning Commission recessed the Feb. 20 hearing and scheduled continuation of the public hearing the following business day at 1:30 p.m. at the county chambers; the county additionally posted the hearing recording to its social media channels and said a YouTube archive would follow.