The Los Alamos, N.M., County Council recently approved agreements for 170 megawatts of solar power from the Four Corners Area and 80 megawatts of battery storage.
In 2013, the Los Alamos Board of Public Utilities set a goal for the Department of Public Utilities to become a carbon-neutral electrical energy provider by 2040.
DPU has been pursuing carbon-neutral power resources to meet this goal. The newly inked agreements are between Los Alamos County and Foxtail Flats Solar, LLC, and between Los Alamos County and Foxtail Flats Storage, LLC.
Over the next two years, Foxtail Flats will build the solar facility and battery storage system northwest of Farmington, N.M.
DPU partners with the Department of Energy in the Los Alamos Power Pool, an arrangement dating back to 1985 in which the parties pool resources for a combined electric load between Los Alamos County and Los Alamos National Laboratory.
The ratio of power usage between the two parties is roughly 1:4 with a combined peak load of 90 MW.
The pool is a mutually beneficial partnership which allows economies of scale that reduce electricity costs for both parties, making it easier for the County and LANL to achieve shared environmental energy goals.
Considered by itself, a 170 MW solar array may appear too large to suit LAPP’s 90 MW load, the county noted.
DPU will resolve this mismatch by using a large amount of the electricity from the solar array to charge the battery system for use at night when the solar array generates no power, and by preparing future agreements to sell the solar power that exceeds LAPP’s needs.
The Foxtail Flats battery stores up to 320 MWh of energy for discharge during periods of peak power costs and requires an average of 40 MW of solar capacity, or 8 hours, for charging from the solar array.
This 40 MW is a portion of the total solar production allowed in the contract. As such, the 170 MW solar array is well suited to meet the LAPP energy needs, charge the battery, and cover the third-party sales contracts for excess power, the county said.
“Nonetheless, because solar power is daytime power, it does not negate the need for other power resources. DPU will still need to make power purchases but the battery will allow power schedulers to reduce the amount purchased, especially when night-time market costs are high,” the county said.
In 2022, the San Juan Generating Station in New Mexico closed. The coal-fired power plant was DPU’s largest energy resource up until that point.
In 2023, Los Alamos County’s subscription to the Carbon Free Power Project was terminated when the Utah Associated Municipal Power Systems pulled out of the project.
Los Alamos had been subscribed through its partnership in UAMPS. The CFPP was to provide nuclear energy through a small modular reactor being built in Idaho.
DPU’s Electric Production staff investigated numerous possible long-term resources for several years before the Foxtail Flats opportunity surfaced in 2023.
The county said that project benefits include:
- Increase in carbon-free (or renewable) electricity load.
- Allows flexibility for load growth as electrification efforts increase.
- Replaces 36 MW that was lost with the closing of the San Juan Generating Station.
- Replaces 8 MW of power expected as a long-term resource that CFPP would have provided.
- Power load is more reliable year-round than the seasonal run-of-the-river generation at the County’s two hydroelectric plants.
- Drives Los Alamos County significantly closer to meeting its 2040 carbon neutral electrical energy goal.
- Drives LANL significantly closer to meeting its 2030 carbon neutral electrical energy goal.
- Costs less than last year’s fossil fuel energy from coal and natural gas plants.
