Rancho Viejo Solar faces obstacles to breaking ground off N.M. 14

May 20—A global energy company planning a large and controversial solar development south of Santa Fe faces a delay that could mean breaking ground in 2025 if the project gains approval, rather than this year, with operations expected to begin by early 2027.

Construction on the Rancho Viejo Solar facility is expected to take a year.

Amid pushback from residents who live near the proposed industrial development — which would be built on 800 acres of private land about a mile off N.M. 14, northeast of the Rancho San Marcos subdivision and west of Eldorado — Santa Fe County is enlisting outside help for review of plans by renewable energy firm AES Corp.

This could add months to the county's land use approval process.

AES Development Manager Jonathan Moore wrote in an email last week the company hopes to have the commercial operation running by Nov. 30, 2026, with a "guaranteed start date" in May 2027.

The company adjusted the project's schedule to align with Public Service Company of New Mexico's energy procurement plan for 2026 to 2028, Moore wrote, "and to better accommodate completion of detailed design, acquisition of building permits and approvals and material procurement."

PNM and AES do not have a contract in place for the project, PNM spokeswoman Kelly-Renae Huber wrote in an email.

Although PNM has seen delays in recent years on solar facilities to replace electricity generated from fossil fuel-powered plants that have shut down, Huber wrote, the utility anticipates "the delays on renewable projects clearing up in the coming years and not impacting PNM's 100% carbon-free electricity goals."

Before construction can begin on the Rancho Viejo Solar facility, the project must gain approval from county officials.

More than three months have passed since the company submitted an application seeking a conditional-use permit to build and operate the commercial solar energy generation and storage facility in the county's "Rural-Fringe" zoning district south of Santa Fe.

The facility would generate 96 megawatts of power and include a 48-megawatt battery energy storage system along with a 2-acre substation onsite, according to application materials.

"The project anticipates a fenced boundary of approximately 688 acres," Moore wrote in an email, "of which 233 acres will be covered by solar modules suspended on east-west trackers along with 4 acres for battery energy storage pads and 2 acres for a project substation sited in the northeast corner of the Project area, subject to final engineered designs."

Residents of nearby Rancho San Marcos and Eldorado have expressed safety concerns — particularly the potential for the lithium-ion battery system to overheat in a "thermal runaway" event.

They have cited thermal runaway and battery fire incidents at other solar farms in recent years, including one at an AES facility in Chandler, Ariz., in 2022.

The county initiated a contract Tuesday with Terracon Consultants Inc. of Albuquerque, a third-party review agency to examine AES' application, county spokeswoman Olivia Romo said.

"Beginning [May 17], they will have twenty-five working days to conduct a complete review with a concentration on the environmental impact report that addresses the battery storage," Romo wrote in an email.

AES will have an opportunity to respond to recommendations from the third-party review and amend its application before the document is brought before a staff hearing officer for a recommendation to the county Planning Commission, Romo wrote.

An initial public hearing on the application may not occur until August, she wrote.

A third-party review is common for such permit applications, county Planning Director Robert Griego said Tuesday.

"After the submittal comes in, we identify which agencies need to review it," Griego said. "In this case, it is an application for a project that we do not have the expertise to review internally."

The company's Jan. 26 application for a conditional-use permit included several reports, including an environmental impact report, a biological survey, a site development plan and summaries of two 2022 meetings between AES staff and neighboring community members.

Battery storage at Rancho Viejo Solar would allow power to be generated during the day and stored until evening, when the demand for electricity increases.

In a February letter to the Planning Commission, resident Selma Eikelenboom-Schieveld asked the project be moved or that the county put firm rules in place to prevent the company "from cutting corners and endangering life, property and the environment."

Eldorado resident and wildlife biologist Carol Beidleman said she believes the county should consider approval of large developments like the proposed Rancho Viejo Solar facility with "rigorous evaluation." Specifically, she said, large commercial projects should be reviewed as "developments of countywide impact" or those that have potential for far-reaching effects on the community, such as landfills, mines and oil drilling operations.

"At the very least, we should look at where these sorts of facilities should be placed," Beidleman said, "and not have them placed where it's opportunistic because a private company and a private landowner want to make a deal."

Like other residents, Beidleman is concerned about a fire.

"Should a fire start, it would go through the juniper savannah, and it could be like the sort of fire that ran through Boulder, [Colo.,] and caused millions in damage," she said. "Outside of the environmental aspects of it that, I also have concerns about, that is the top concern."

A March letter from San Marcos Association President Dennis Kurtz argues the facility should not be eligible for a conditional-use permit. He calls the planned solar farm a "utility-scale" project as opposed to the "neighborhood-scale" commercial solar operations that should be allowed in the sustainable land development code.

Kurtz said his organization has not taken a position on Rancho Viejo Solar, but believes the proposed facility deserves the amount of countywide discussion that would come from the project qualifying as a development of countywide impact.

"It's the size of an airport," Kurtz said. "Let everyone in the county have their say. ... We want to promote discussion, but without it being a DCI, you only have to notify people within 500 feet. We feel a larger discussion should happen."

A report included with AES' application addresses the company's plans for preventing a fire in the battery system.

"If a battery fire is initiated, the enclosures planned for this site will release fire suppressant in large concentrations directly into the initiating cell, removing heat and preventing thermal runaway throughout the enclosure," the fire protection plan states.

The company pledges to perform a hazard mitigation analysis, along with a "site and product specific fire risk assessment and a first responder plan," the report states.

The project is planned to be built in the county's District 5, represented by Commissioner Hank Hughes.

Hughes said he is prohibited from engaging in ex parte discussions about AES' application, which could come before the County Commission for a decision.

"Since it's a land use case, I really can't comment on it," Hughes said Thursday. "I've heard plenty from both sides, and I will consider everything when it comes before us. It should be interesting, I will say that."