DESRI Breaks Ground on 270 MW Foxtail Flats and Four Mile Mesa

D. E. Shaw Renewable Investments (DESRI) broke ground on May 14, 2026, on two solar-plus-storage projects on Ute Mountain Ute tribal land in San Juan County, New Mexico, that will deliver 270 megawatts of solar generation and 180 megawatts of battery storage. The combined Foxtail Flats and Four Mile Mesa facilities represent one of the region’s largest renewable energy investments to date, The Durango Herald reported on May 20, 2026.

The Project

The Foxtail Flats facility will provide 170 MW of solar power paired with 80 MW of battery storage under a 20-year fixed-price power purchase agreement (PPA) with the Incorporated County of Los Alamos. Four Mile Mesa will offer 100 MW of solar and 100 MW of battery storage, also under a 20-year PPA, this time with Public Service Company of New Mexico (PNM). The Foxtail Flats PPA will flow into the Los Alamos County Department of Public Utilities power pool, a collaboration involving Los Alamos National Laboratory, the Department of Energy, the National Nuclear Security Administration, and Sandia National Laboratories. SOLV Energy is the engineering, procurement, and construction (EPC) contractor, commencing construction the week of May 14. Tierra Adentro Growth Capital (TAG Capital) is the equity financing partner, with financing finalized in April 2026. At peak construction, the projects are expected to employ nearly 600 individuals and generate enough power for approximately 60,000 homes. Both facilities are scheduled to be operational by spring 2027. SOLV Energy disclosed a combined solar scope of 394 MWdc across the two sites.

Why It Matters

These projects are part of a broader clean-energy partnership announced in July 2024 between the NNSA and Los Alamos County, aiming to power Department of Energy laboratories with carbon-free solar and storage. Foxtail Flats was designated as the lead project for the laboratory procurement track. The combined 270 MW solar and 180 MW battery capacity is intended to support the computational loads of DOE laboratories, including high-performance computing systems like Trinity and Crossroads, through evening peaks when solar generation declines. The 20-year fixed-price PPAs are structured to shield the laboratories and the county from fluctuations in fuel prices and capacity markets.

Critical Perspective

Neither DESRI, SOLV Energy, nor the Los Alamos County Department of Public Utilities has publicly disclosed the levelized cost of energy over the 20-year PPAs, nor has a breakdown of construction costs between the two sites been provided. The specific battery cell vendor and chemistry also remain undisclosed. The financing structure does not detail the division of debt and equity contributions among DESRI, TAG Capital, and any potential tax-equity partners. Furthermore, SOLV Energy has not specified its commitment to hiring tribal members through the Ute Mountain Ute Tribal Employment Office for the approximately 600 peak construction jobs. The estimate of powering 60,000 homes relies on average U.S. household consumption and does not account for the distinct load profile requirements of high-performance computing facilities.

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