US battery energy storage manufacturer Viridi has supplied an NMC lithium-ion BESS to Oak Ridge National Laboratory (Oak Ridge) for research into the integration and control of distributed grid resources.
Viridi’s RPS 150 system was installed at the Power Distribution Field Test Site within Oak Ridge’s Grid Research Integration and Deployment Center, known as GRID-C. It formed part of the testing platform for a US Department of Energy resource integration and evaluation project.
The RPS 150 has a nominal capacity of 146.7kWh, of which 132kWh is usable, and maximum continuous charge and discharge power of 30kW. It contains three Viridi RPS 50 battery packs operating at a nominal 600V DC.
Viridi said its systems use cylindrical nickel manganese cobalt lithium-ion cells sourced from LG and Panasonic. The company’s battery-pack architecture is designed to prevent a thermal event in one cell propagating to neighbouring cells.
The Oak Ridge project concerns a control system developed to coordinate clusters of grid resources so that they can respond collectively to utility requirements. Initial testing was conducted indoors using emulated energy sources and battery storage.
Oak Ridge’s live distribution test grid
Researchers subsequently moved the system to Oak Ridge’s live distribution test grid to examine interactions between physical equipment and account for real battery charging and discharging behaviour. Oak Ridge integrated its own converter system with the Viridi battery during the field trials.
Testing has now concluded, with the laboratory expected to present its findings in the coming months.
“This project bridges an important gap by integrating real electrical equipment to understand realistic performance challenges, proving the robustness of ORNL’s new control strategies and AC/DC architecture for supporting the future grid,” said Dr Madhu Sudhan Chinthavali, electrical systems integration programme manager at Oak Ridge. “Viridi’s battery integrated seamlessly with our management system, and its engineering team supported our researchers throughout testing and integration, making them a valuable partner.”
GRID-C provides facilities for developing and validating power electronics, controls and grid-management technologies. Its distribution field test site incorporates solar generation, energy storage and controllable loads connected to a live grid. The laboratory lists the site’s storage resource as a nominal 150kWh, 600V system.
“Being selected by Oak Ridge National Laboratory to support the project is a milestone for Viridi and a validation of what we have built,” said Jon M. Williams, CEO of Viridi. “When a DOE national lab chooses your technology to support their research, it is the highest bar a battery system can meet. We built Viridi’s fail-safe BESS to perform in exactly these kinds of environments, and we are proud to be partnering with ORNL to advance the grid modernisation solutions that utilities across the country need.”
Viridi said further joint projects with Oak Ridge are planned.
Photo credit: Amy Smotherman-Burgess/ORNL, US Department of Energy)
