GM and ABB demonstrate community energy storage system built from 5 used Volt batteries; Duke Energy testing
|GM and ABB partnered to produce a prototype back-up power storage unit that repackages five used Volt batteries into a modular unit that becomes an uninterruptible power supply and grid power balancing system. Click to enlarge.|
During a symposium for the media on GM’s electrification efforts, including a preview of the Spark EV to be unveiled at the LA Auto Show in two weeks, General Motors and ABB showed and demonstrated a new grid distributed micro-storage (at grid scale) system—i.e., a community energy storage system—built from five used Chevrolet Volt batteries.
The modular air-cooled unit, which can provide about 25 kW of power for about 2 hours (50 kWh of energy capacity), is envisioned to be paired with a neighborhood transformer, said Dan Sowder from Duke Energy, which is putting one of the units into test. Duke supports about 4.2 customers per transformer, so this system would benefit those four customers with respect to the value stream, he suggested.
GM and ABB suggest that the modular unit is capable of providing two hours of electricity needed by three to five average American homes.
The system is built with the cells which are removed and repackaged from the T-pack used in the Volt. While the pack in the Volt is liquid cooled, the repurposed cells, given the duty cycle of their new applications, can be air-cooled. (For one thing, each pack only operates at 5 kW, as opposed to their 111 kW output in the Volt.)
The system can be connected to single phase or three phase; the round-trip efficiency is just under 86%, ABB said. The inverter, supplied by ABB, communicates with the utility—Duke Energy in the test case—and the battery management system provided by GM.
The system is designed to work autonomously; in addition, the utility could override for manual dispatch.
A prototype of the uninterruptible power supply and grid power balancing system was demonstrated during GM’s Electrification Experience, powering all the support lighting and audiovisual equipment in an “off-grid” structure used for the event.
During the demonstration, the energy storage system was run in a “remote power back-up” mode where 100% of the power for the facility came from Volt batteries through ABB’s Energy Storage Inverter system. A similar application could be used to power a group of homes or small commercial buildings during a power outage; allow for storage of power during inexpensive periods for use during expensive peak demand; or help make up for gaps in solar, wind or other renewable power generation.
GM’s battery development extends throughout the entire life of the battery, including secondary use. In many cases, when an EV battery has reached the end of its life in an automotive application, only 30 percent or less of its life has been used. This leaves a tremendous amount of life that can be applied to other applications like powering a structure before the battery is recycled.—Pablo Valencia, GM senior manager of battery lifecycle management
GM and ABB last year demonstrated how a Chevrolet Volt battery pack could be used to collect energy and feed it back to the grid and deliver supplemental power to homes or businesses.
ABB’s research center in Raleigh, NC, conducted the research and development, and ABB’s Medium Voltage business unit in Lake Mary, Fla., is managing the proof-of-concept testing, market research and product development. As the world’s largest EV fast-charging company and leader in smart grid and energy storage, ABB works with other auto companies, battery manufacturers and utilities to help make electric power and industrial operations more productive and efficient.