Deployment of UEP Battery Energy Storage System on the Navajo Nation

On May 5, 2022, the Sandia Energy Storage Demonstration Projects team, supported by the DOE Office of Electricity’s (DOE-OE) Energy Storage Program, successfully deployed a 3 kW/13 kWh rechargeable zinc manganese dioxide (ZnMnO2) battery system to replace lead acid batteries at an off-grid home on the Navajo Nation in Arizona. It is estimated that the battery can supply the home for 8-12 days without solar power. Sandia has partnered with the Navajo Tribal Utility Authority (NTUA) and Urban Electric Power (UEP) for over two years on development and deployment of this project. The new UEP battery system is the first of three demonstration deployments that will provide power to off-grid homes while assessing the performance of the rechargeable ZnMnO2 batteries in an applied environment.

Feature image above:
L to R: Stan Atcitty (Sandia), Henry Guan (Sandia), Alexis Brown (NTUA), Umer Anwer (UEP), David Rosewater (Sandia), Derrick Terry (NTUA)
Photo credit: Stan Atcitty

According to Stan Atcitty, Tribal Energy Storage Lead at Sandia and a member of the Navajo Nation, “Sandia has been involved in energy equity with tribal communities R&D for decades. This is another example of actual deployment of energy systems for underserved communities. This is not just a theoretical priority for Sandia, we are having a direct impact by increasing their tribal sovereignty and reducing the energy divide.”

The home where the system was installed near Dilkon, AZ did not have access to power from the electric grid due to its distance from NTUA’s electric distribution infrastructure. The residents have relied on a solar PV and battery storage off-grid system as its main power source. With an area of approximately 17.5 million acres, the Navajo Nation is the largest Native American reservation in the United States, however, due to the sparse nature of the reservation, there are currently over 15,000 residents living without power.

“Tribal projects are not only an obligation for DOE,” said Dr. Imre Gyuk who directs DOE-OE’s Energy Storage Program “but they provide valuable experience for off-grid applications in the U.S. and abroad.”

The NTUA has installed over 500 off-grid systems to provide power to residents who do not have access to electrical infrastructure. These systems consist of flooded lead-acid, sealed lead-acid, and lithium-ion battery technologies.

Derrick Terry, NTUA Renewable Energy Specialist and a member of the Navajo Nation, “NTUA takes a three-pronged approach to deploying these systems – safety, reliability, and efficiency. Our 30-year partnership with Sandia has helped us with the latest knowledge and technical advisement so that we can deliver these systems to our remote families.”

The new batteries installed on the Navajo Nations feature safe and non-flammable aqueous zinc-anode chemistry with earth abundant manganese dioxide used in the cathode. The battery composition is similar to that of common household AA batteries, but UEP has made them rechargeable using their patented additives. These additives allow for facile proton intercalation and de-intercalation processes to take place in the manganese dioxide cathode without leading to its crystal structure breakdown, which is one of the main problems of the primary battery.

“Urban Electric Power’s rechargeable alkaline batteries expand energy equity by bringing off-grid power to homes that would not otherwise have electricity,” says Gabriel Cowles, UEP VP of Commercial Strategy and Finance. “Our experienced partners at Sandia National Laboratories and the Navajo Tribal Utility Authority helped optimize the energy storage system’s functionality and ensured the system was properly installed on site.”

Zinc self-discharge is also curtailed in UEP batteries allowing for greater reversibility and long-term use, making these batteries ideal for micro-grid applications. The materials used in the UEP chemistry also can be sourced in the United States, thus increasing our energy security.

Sandia has prioritized enabling clean, reliable, and affordable energy on tribal lands through its Tribal Energy Security Program.

This project and all Sandia demonstration work is funded by Dr. Imre Gyuk of the Department of Energy Office of Electricity Energy Storage program.