Will Solar Energy Rise in Santa Fe Before Opportunity Sets?

Editor’s Note:

Alternatives to fossil fuel have long-standing support across Santa Fe and New Mexico, evidenced by renewable energy from wind and solar panel farms generated around the state. Fast-moving projects operating on emerging technologies can be fraught with peril, and in the case of utility-scale solar farms and the battery energy storage systems that come with them, they call it thermal runaway.

Since Virginia-based AES first proposed the Rancho Viejo Solar project in 2022, protest and concern have followed. Three years after AES first announced its intentions, the Rancho Viejo project is still not under construction.

Protest has met the project each step in the permitting process from several well-organized groups on a campaign to stop the installation.

Last month, Santa Fe County Commissioners denied an appeal of the conditional-use permit AES was granted by the Santa Fe County Planning Commission in February. That leaves opponents with only district court to turn to. With an appeal imminent, SFR today publishes an overview of the project and the controversy surrounding it for Santa Feans who might not have heard a utility-scale solar farm had been proposed about three miles south of town or that anyone had been fighting over it.

This marks the start of a series of stories and interviews SFR plans to publish based on research and reporting that began last December. 

After hours of testimony in December compounded by even more hours of testimony in August, the Rancho Viejo Solar Project appears to be on the precipice of construction—but no shovels have yet cracked the earth on the 800-acre parcel just south of Santa Fe where Virginia-based AES plans to build.

Folks living out along the east of the Turquoise Trail Scenic Byway hope no shovels ever go to work on behalf of the project aimed at producing 96 megawatts of power and roughly 45 megawatts of battery storage. After Santa Fe County Commissioners voted 4-1 last month to deny an appeal of the conditional-use permit AES got from the Santa Fe County Planning Commission in February, the stage is set for the massive solar energy and battery storage installation that worries thousands of its future neighbors. 

“We were disappointed but not surprised,” Clean Energy Coalition of Santa Fe President Lee Zlotoff, whose home is within view of the proposed project, told SFR in a phone interview last week. “Because the county's behavior in this whole process has struck us as being remarkably cavalier, and biased in favor of AES.” 

For three years, thousands of local residents, whether members of the CEC or the other dissenting factions, have sent emails, used social media and gathered en masse with one goal: stop the Rancho Viejo Solar project. But why? CEC members are like most other New Mexicans in their support of solar energy, but this installation is planned to drop a little too close to home. The primary concern? Safety. 

Why Not Rancho Viejo?

Among the loudest voices against the AES project is Zlotoff, president of the CEC and the mind behind McGyver. The Hollywood mogul lives in Eldorado in a home where the project will be visible from his backyard, but it’s not the view that worries him. He is more concerned about the above-ground gas line just on the other side of his property, which he says is about a mile from the proposed solar plant and its system of lithium-ion batteries.

The coalition of concerned residents he presides over is a couple thousand people strong and growing. Few, if any, of the members oppose solar energy on its face. So, why have thousands of local residents signed petitions protesting the Rancho Viejo project?

Talk to any CEC member, including Zlotoff, or any of the other factions against the project and you will soon hear the term thermal runaway. Those opposing Rancho Viejo don’t agree on everything, but they all agree thermal runaway is the primary reason the project should move or vanish altogether.

The fast-moving, high-intensity fires associated with the lithium-ion battery technology used to store and move energy have made plenty of headlines. Battery energy storage systems on eight occasions since 2019, have been at the root of thermal runaway events.

AES storage systems have twice caught fire in that time. The company’s McMicken battery storage facility in Surprise, Ariz., was the site of a “cascading thermal runaway event” started by a single battery failure. Eight firefighters were hospitalized after opening the steel housing to oxygen and unleashing a gas explosion. Three years later, the BESS installed at the 10-megawatt Dorman battery storage facility owned by AES in Chandler, Ariz. burned for 10 days. There were no injuries, but businesses and residents evacuated several times as a precaution to avoid potential toxic gases spread from the smoldering wreckage, according to reporting from the Electric Power Research Institute (EPRI).

The most recent high-profile fire started in January at the Moss Landing Power Plant in Moss Landing, Calif. That fire is the fourth since 2019 at the site, which has no affiliation with AES. The January fire followed a previous malfunction in September of 2021.

Fear of thermal runaway events has led to concerns about BESS across the country. Earlier this month, Environmental Protection Agency Administrator Lee Zeldin held a press conference in Hauppauge, New York, with a group of Long Islanders concerned with New York’s push to install BESS nearby. According to the EPA, the state of New York has expedited approvals for installations of the systems in densely populated areas, including New York City and its suburbs. 

Echoes of protest must be music to the ears of Randy Coleman, vice president of the CEC. Coleman is an electrical engineer living in Eldorado who believes solar energy is the right solution but disapproves of the AES plan. 

“We think there’s a better alternative,” he told SFR in March. “We believe in an approach that is based on successes and is already happening in places like Taos—microgrids. We believe they can be established quickly and provide a safer solution than the Rancho Viejo project.”

Coleman, and numerous other CEC members, fear the residential location is unprecedented. He told SFR utility-scale solar and battery storage are viable but believes better locations already designated for the use of energy transmission are available.

“The Rancho Viejo project is not the only option.” Coleman told SFR. “There are other Santa Fe County conditional-use permit applications in the works for solar and battery projects that are even larger.”

A microgrid is a local electrical grid with defined electrical boundaries, acting as a single and controllable entity. It is able to operate in grid-connected and off-grid modes, but they do rely on lithium-ion batteries.

“Microgrids are a lot smaller than what AES plans to build,” Coleman told SFR. “That alone reduces risk.”

While safety tops the list of concerns of detractors, Santa Feans have expressed concerns about damage to waterways and natural habitat along the Turquoise Trail, including the Burrowing Owls that call it home. The decommissioning of plants and equipment has been raised, and CEC members have questioned the transparency AES has offered throughout the process. 

What’s right about the plan?

Anyone living near the proposed site who’s seen video footage or images from the Moss Landing catastrophe is likely to oppose Rancho Viejo. However, proponents of the project believe comparing Moss Landing to Rancho Viejo is apples and oranges.

AES acknowledges that battery storage systems come with inherent risks. Joshua Mayer, who is project manager for AES for Rancho Viejo, told Searchlight New Mexico last year that AES learned a lot from its two Arizona fires, resulting in design changes that “will look and operate very differently from the technology used just a few years ago” at Rancho Viejo. Mayer is among those who’ve agreed to an interview with SFR as part of our continuing coverage.

The property owner, the Rancho Viejo Limited Partnership, has expressed confidence. Warren Thompson, who is one of the partners, told Searchlight, “Everything is containerized, and it’s surrounded by a gravel boundary—a noncombustible buffer zone. I’m not worried at all.”

Supporters of the project are also quick to point out the overall safety rate of battery systems. Following the Moss Landing disaster, a spokesperson for the American Clean Power Association told the online publication Utility Dive only 20 fire-related incidents had occurred at utility-scale lithium-ion battery installations despite a 25,000% increase in installed capacity since 2018.

EPRI, which collects and analyzes data about BESS fires, reports the BESS failure-rate hovers around 1 or 2 percent. EPRI found there were about the same number of fires in 2023 as there were in 2019, “even as global battery deployments have increased 20-fold.”

Proponents also point to issues the Moss Landing facility had that Rancho Viejo never will. To start, the Moss Landing system was housed inside an existing structure not customized for a BESS.

Also, the battery used there has proven to be more prone to thermal runaway. Multiple reports indicate the Vistra system at Moss Landing used LG batteries made with nickel-manganese-cobalt chemistry—originally developed for electric vehicles. They offer lots of capacity, but that extra energy density can be a problem if defects cause the batteries to heat up, and that’s where thermal runaway comes from, according to EPRI reporting.

Turns out, LG batteries were used at facilities where catastrophe struck at several places, including the aforementioned McMicken BESS in Surprise, Ariz., and the Gateway project fire in Escondido, Calif., in May of 2024. Those incidents pushed General Motors to remove LG batteries in its $2 billion Chevrolet Bolt battery recall.  LG even recalled some of its residential battery products in late 2020.

New BESS installations tend to feature rows of modular battery containers rather than enclosed buildings like at Moss Landing. AES lists its safety protocols on its website, along with a video depicting the fire-suppression system at work putting out a potential thermal runaway event in testing.

Though testing has its limitations, the video evidence along with improved technology and overall safety record of BESS is enough to convince the local chapter of the Sierra Club to endorse the project. 

SFR talked to John Buchser, Northern Group Chair of Sierra Club Rio Grande Chapter earlier this year. He’s been fighting for solar energy for 25 years and sees this project as a chance the community can’t pass up. In our conversation, Buchser first addressed fears over thermal runaway. 

“There have been concerns from recent fires like the one at Moss Landing, but technology and safety has rapidly evolved to address those issues,” Buchser tells SFR. “BESS fire codes and construction codes were updated in 2024. I’ve seen video of the suppression systems. A typical [BESS] system resembles a shipping container with racks of batteries inside. Because you’ve got at least 1,000 or more individual batteries in a container, it’s important to arrange them in several layers.”

Layers, Buchser tells SFR, allow safety systems to address any failure and possible fire from a single cell before it impacts its neighboring cells.

“There have been no fires that have escaped a battery storage facility site,” he tells SFR. “The fires that have happened led to updated safety strategies and standards to reduce potential risk.”

Buchser, who retired in 2016 as a computer system architect for the New Mexico Office of the State Engineer, has been bullish on the project since it was first announced, saying Rancho Viejo “has many very favorable features.”

“We’re talking about a large area with minimal vegetation,” Buchser told SFR. “That keeps fire risk low.”

The other boon is the proposed site’s proximity to an existing PNM electrical switching station.

“Being so close to a substation means once the construction is completed, it’s plug and play,” Buchser told SFR.

He also noted the proximity of a fire station, and how the “BESS is a mile and a half away from the nearest homes.”

A Matter of Trust

As of SFR’s publication deadline, Santa Fe County had not yet formally issued an order for AES to proceed. That formality is expected any day, and once it does a 30-day clock is triggered for the appeal process. According to Zlotoff, his organization is primed with arguments and financial resources to back them being heard in court for the long haul.

Once the scales of justice are engaged to determine this conflict, safety will be the first and most prominent issue argued.

Commissioner Lisa Cacari Stone, who was the lone County Commissioner to vote against AES, explained why on the third day of hearings.

“The proximity of this large-scale project to neighborhoods and Rancho Viejo continues to create potential hazards and can be very detrimental to all those in the area,” she said. “My vote is not against solar energy, it is against this particular proposal by AES because it does not meet—based on the evidence I’ve reviewed, written submissions and testimonies—the high standards we owe all of our communities.”

Zlotoff also questions whether AES has acted with real transparency or whether County Commissioners demanded it.

“They played games early on by calling this a commercial project as opposed to a utility-size project,” Zlotoff said. “They played the kind of word games that they've needed to and been doing everything in their power to shoehorn this into a place where, by all definitions and anybody else's, it should’ve been prohibited. We should never have even gotten to the point of the BCC (Board of County Commissioners) having to make a decision about this. That leaves us sitting here thinking either they're possibly, but unlikely, corrupt—no way to determine that, and it’s not an accusation I'm going to make. But it makes you wonder: have they agreed to something behind the scenes and are they just doing everything they need to do to fulfill that agreement.”

While the EPRI data suggests that grid-scale lithium-ion battery storage is largely reliable, Zlotoff questions the motives of the research.

“The body that oversees this (EPRI) they have done studies of if you pour water on one of these things does it put toxic chemicals into the ground. They will not publish those studies. They’re an oversight organization, but they’re an oversight organization that works for the industry. Why wouldn’t you publish it unless it was damaging information?”

Zlotoff also questions whether a company like AES, which he says is known for being “the cheapest most cost-cutting company out there” and has “faced numerous fines over the years,” is the kind of company people should trust with their homes and lives. Zlotoff questions whether residents can be convinced this project won’t be among the small percentage of BESS facilities that have caught fire because he has no confidence AES has been or will be transparent. 

Thousands of Santa Feans agree.

“We have a very strong constituency—over 2,100 people are on our mailing list, and we had 1,600 signatures on a petition,” Zlotoff said. “And we have a war chest with which two pay lawyers to fight this. We've told our constituents, if we need more, we'll ask you for more, but we're not. Even though now would be the perfect time to ask you for money, we’re not because we have the money. We've been planning for this. We're a smart, and I'd like to think, thoughtful, diligent and transparent organization of volunteers. Nobody gets paid in our organization. The only people who get paid are the attorneys or the people who make flyers or whatever, you know, that's who gets the money, but it doesn't come to any of us.”

In the meantime, SFR will share more of its reporting, including the readiness of firefighters and other emergency responders for an installation of this scale and conversations with folks for and against the project.

New Mexico’s Solar System

New Mexico ranks second in the US for its capacity to generate solar power, according to the Office of Renewable Energy at the State Land Office, which also has about nine million acres of land available for lease to renewable energy companies. As of this month, New Mexico has 87 utility-scale solar farms, according to Cleanview.co's project tracker. 

Solar energy became an alternative energy source in New Mexico starting in 1977 with the passage of the Solar Rights Act, but it wasn’t until after the state passed its first Renewable Portfolio Standard (RPS) in 2004 substantial growth followed.

Seven years later, the 30 megawatt Cimarron Solar Facility opened and became the largest solar array in New Mexico. Three years later, the 52 megawatt Macho Springs Solar Facility became top dog. In 2016, the combined 140 megawatt produced at the Roswell and Chavez County Solar Energy Centers made it the largest.

When the Buena Vista Energy Center was completed in Otero in 2023, it became New Mexico’s largest solar photovoltaic power plant with a generation capacity of 150 megawatts.

AES has proposed a utility-scale project on property originally zoned for community solar projects. A 2022 county code change to the definition of "commercial solar facilities" paves the way for the project to proceed.

What’s the difference between a community solar project and utility-scale? Any solar project that benefits flow to multiple customers within a certain geographic area is considered “community.”  Projects that generate electricity sold to a wholesale utility buyer rather than an end-user with a capacity of 10 megawatts or larger is considered utility-scale.

Of course, not all utility-scale solar projects are owned by the same company nor are they all fully backed by battery storage systems. 

The Rancho Viejo Solar Project

Virginia-based AES, a global energy-production conglomerate, agreed to lease about 800 acres just south of Santa Fe in 2022, contingent upon the company’s ability to get a conditional land-use permit from the Santa Fe County Planning Commission. When AES got that permit last December, AES Project Manager Joshua Mayer said the company “hoped to be up and running by the end of 2028.”

AES’s information website for the project claims the proposed power plant would produce more than ​​277,315 megawatt-hours of electricity annually.

The initial proposal also promised:

• The project would sit on roughly 680 acres of an 8,200-acre site.
• Offsets the equivalent of 119,965 metric tons of carbon dioxide per year
• Enough clean energy to power 34,000 New Mexico homes annually
• Payments in Lieu of Taxes revenue expected upwards of $7 million over the life of the project 
• AES as longterm owner and operator
• Its 200,000 solar panels would generate 96 megawatts of power.
• Its lithium-ion battery energy storage system, sitting on two acres in the site’s northeast corner, would store 277.8 megawatt-hours of energy—enough to send 48 megawatts of power to PNM’s electric grid for four hours. 
• A new overhead transmission line about two miles long would connect the project to the grid.
• The project will be set-back a minimum of 1,000 feet from any adjacent property boundary, nearly 2,000 feet from the nearest residence in San Marcos and 1.3 miles from the nearest residence in Eldorado.
• The BESS installation will be located approximately 1.5 miles from the closest residence.
• At the end of the project’s life, a decommissioning plan outlines the responsibilities and methods for full project infrastructure removal and site restoration.
• The decommissioning bond, Letter of Credit or Parent Guaranty will be held in the County’s name and will be reviewed to ensure it satisfies current market cost to decommission project

Source: AES

Other projects of similar scale

• Diamond Tail Solar and Storage is a proposed solar farm in eastern Sandoval County, which will include a 220 megawatt array, plus 110 megawatts of four-hour battery storage. 
• Atrisco Solar was installed in Oct. 2024 and boasts a capacity of 364 megawatts of solar and 1,200 megawatt hours of battery storage. It is one of the largest solar-plus-storage projects in the United States. 
• San Juan Solar I is a solar farm located in San Juan, New Mexico. It has a total capacity of 200 megawatts and 100 megawatts of battery storage. It was built in October 2024.
• Sky Ranch Solar is a solar farm located in Valencia, New Mexico. It has a total capacity of 190 megawatts and uses a 50 megawatt BESS. It was built in March 2024. 

Solar Energy Timeline

1977: New Mexico passes the Solar Rights Act. This established the right to use solar energy for a home or business as a property right. A year later, the state passes a net metering law. It requires utilities to give solar users credit for sending excess power to the grid.

2004: The state passes its first Renewable Portfolio Standard (RPS). It requires the state’s investor-owned utilities to get 20% of their power from renewable energy by the year 2020. Rural electric cooperatives must meet a lower standard of 10% renewable energy. The state also requires utilities to offer their customers a way to choose green power for their homes and businesses.

2006: New Mexico introduces the Solar Market Development Tax Credit (SMDTC), offering a significant tax credit for solar photovoltaic systems. 

March 2019: Gov. Michelle Lujan Grisham signs the Energy Transition Act, setting bold statewide renewable energy standards and establishing a pathway for a low-carbon energy transition from coal. New Mexico’s Energy Transition Act requires utilities to make the transition from electricity produced from fossil fuels to renewable energy sources, with benchmarks starting in 2019 on the way to 100% renewable by 2045.

2021: The Community Solar Act becomes law, developing programs that allow residents, businesses, and nonprofits to purchase shares in a community solar project. 

Aug. 2022: Rancho Viejo Solar project is proposed by Virginia-based AES, targeting property between Rancho Viejo and Eldorado in Santa Fe County. With necessary approvals, the solar panel array would be the largest in Santa Fe County and one of the larger facilities statewide.

Jan. 2023: The San Marcos Association, representing local residents, calls on County Commissioners to designate “utility-scale renewable energy projects” as “developments of countywide impact,” the same category as landfills, mines and oil and gas operations and one that would require more public review and oversight.

May 2023: Amid pushback from residents, Santa Fe County hires Terracon Consultants to help review the AES plans.

Aug. 2023: Project opponents claim a June 2022 county code change to the definition of "commercial solar facilities" violated the Open Meetings Act. County officials deny this.

Jan. 2024: A year after the Rancho Viejo proposal goes under review, county staff conduct a virtual meeting on the development and are met with a barrage of questions and concerns from the public.

March 2024: Rancho Viejo opponents win public access to details of the project AES previously withheld, citing trade secrets.

April 2024: The State of New Mexico is awarded a $156 million Solar for All grant, a portion of which will support community solar efforts in the state.

Dec. 2024: Santa Feans pack into a meeting room in downtown Santa Fe to register their opposition to the facility in front of the county’s hearing officer, who subsequently recommends the Planning Commission deny AES a conditional land-use permit.

Feb. 2025: After more than 12 hours of public testimony over two days and a closed-door discussion, the Planning Commission votes 6-1 to approve a conditional land-use permit for the Rancho Viejo Solar project. The Clean Energy Coalition of Santa Fe County immediately appeals, setting up more hearings before the Santa Fe Board of County Commissioners. 

June 2025: Commissioners announce the next public meeting on the controversial project will be at their space-limited commission chambers downtown, rather than at a larger venue, citing limitations imposed by state law. Protests are loud, but space doesn’t appear to be an issue during three days of hearings.

Aug. 2025: Opponents peacefully protest outside the commission chambers prior to the first day of hearings, which are planned for two days. However, discussion pushes into a third day before County Commissioners call a recess. They reconvene two weeks later and continue discussion through the morning before voting 4-1 to reject the appeal and grant the conditional land-use permit to AES for the project. The president of the CEC confirms to SFR the organization will appeal the decision, setting up a date in district court.