Grid equipment supplier ABB and General Motors demonstrated on Tuesday an energy storage system that combines electric vehicle battery technology and a grid-tied electric power inverter.
The two companies are building a prototype that could lead to Chevrolet Volt battery packs storing energy, including renewable wind and solar energy, and feeding it back to the grid.
The system could store electricity from the grid during times of low usage to be used during periods of peak demand, saving customers and utilities money. The battery packs could also be used as back-up power sources during outages and brownouts.
Using Volt battery cells, the ABB and GM team is building a prototype system for 25-kilowatt/50-kWh applications, about the same power consumption of five U.S. homes or small retail and industrial facilities.
GM and ABB estimate that, during an outage or brownout, 33 recycled Volt batteries will have enough storage capacity to power up to 50 homes for about four hours. Over time, batteries lose their storage capacity. After seven to 10 years, their storage capacity decreases to about 70% of what they had when new. Furthermore, the batteries are the most expensive component of plug-in electric vehicles. These tired batteries are still suitable for grid storage.
Chevrolet Volt provides an eight-year or 100,000-mile warranty on its battery pack, GM expects these batteries will be able to power the Volt for 10 years so the earliest application likely would come in 2021.
“Our tests so far have shown the viability of the GM-ABB solution in the laboratory and they have provided valuable experience to overcome the technical challenges,” said Pablo Rosenfeld, ABB’s program manager for Distributed Energy Storage Medium Voltage Power Products. “We are making plans now for the next major step – testing a larger prototype on an actual electric distribution system.”
ABB has determined its existing power quality filter (PQF) inverter can be used to charge and discharge the Volt battery pack to take full advantage of the system and enable utilities to reduce the cost of peak load conditions. The system can also reduce utilities’ needs for power control, protection and additional monitoring equipment. The team will soon test the system for back-up power applications.
Last year, General Motors signed a definitive agreement with ABB to identify joint research and development projects that would reuse Chevrolet Volt battery systems, which will have up to 70 percent of life remaining after their automotive use is exhausted.
