Technology Solution

Energy storage is a key enabling technology in the electric grid’s ongoing transformation to generate cleanly, be more resilient, and host ubiquitous distributed energy resources. Battery energy storage systems are being deployed to help increase the value of renewable generation at distributed and utility scales, provide customers with uninterruptible and backup power supply services, and meet grid support needs over durations of up to several hours.
This pilot focused on performance testing of zinc manganese dioxide (ZnMnO2) batteries developed and integrated into an energy storage system by Urban Electric Power (UEP) for long-duration applications. UEP’s technology leverages the same chemistry used in familiar “AA” alkaline battery cells, drawing on abundant and affordable raw materials but instead rechargeable for grid-tied energy storage. Cells are compliant with applicable safety standards and, unlike lithium-ion technology, are not susceptible to thermal runaway. UEP manufactures its batteries and assembles its storage systems in New York, and balance-of-system components also are made in the United States. In addition to uninterruptible power supply (UPS) products, UEP is developing energy storage solutions expected to reach commercial readiness in 2022 for customer and utility applications.

Project Overview

In this pilot project, EPRI and UEP collaborated to investigate the performance characteristics of the company’s ZnMnO2 battery storage system, assess suitability for utility use cases, and inform product development. Key project milestones included system manufacturing, shipping to the test site, system installation and commissioning, characterization testing according to Energy Storage Integration Council (ESIC) protocols, and use case testing.
The ZnMnO2 system under test has the following specifications:
• Rated power: 10 kW

• Maximum power: 20 kW
• Rated energy: 40 kWh
• Maximum energy: 60 kWh
• Operating voltage range: 600-350 VDC
Due to technology challenges encountered with characterization testing at EPRI’s SolarTAC facility in Colorado, a duplicate ZnMnO2 system was manufactured and installed at UEP’s factory in New York to support a parallel testing program.


Results & Learnings

The tight timeline for this project required expedited battery manufacturing and system assembly, as well as alternative sourcing of some components, such as the battery racks. Nonetheless, manufacturing and installation proved straightforward and were completed on time. System characterization testing following ESIC protocols— including charging/discharging to establish nameplate power and capacity—was performed at SolarTAC and is ongoing at UEP’s facility, to be followed by use case testing. Test results like those shown in the above graphs have been revealing in demonstrating discharge periods ranging from 4 to 16 hours applicable for long-duration energy storage use cases. Deployment experiences also are providing feedback to product development. Additional commissioning support for demonstration and pre-commercial energy storage systems will help ensure batteries arrive safely, are monitored during initial use, and set up for optimum operation. The devices tested at SolarTAC and in New York do not incorporate a battery management system (BMS) as ZnMnO2 technology does not require one. Learnings from the testing have prompted UEP to evaluate how BMS integration could improve performance and functionality for end-users. UEP’s batteries are compatible with commercially available power electronics, and inverters from several manufacturers are currently used in its energy storage systems. UEP is actively collaborating with these manufacturers to further optimize system integration and help firm up product supply for future projects.

Download full report here.

To learn more about Urban Electric Power’s rechargeable alkaline battery technology, see

To set up an interview with one of its engineers, journalists may contact Peter Kelley at, +1 202-270-8831.