Supply and demand across an electrical grid vary continuously, but AC frequency levels must be maintained within a narrow range. Electric utilities perform frequency regulation services by adding or removing generators and load resources as needed. In the future, fleets of EVs equipped with vehicle-to-grid (V2G) capability could perform this necessary service much more quickly than current technology.

Southwest Research Institute (SwRI) has deployed a vehicle-to-grid aggregation system for a fleet of electric delivery trucks that has been qualified by the Electric Reliability Council of Texas (ERCOT), the local agency that handles frequency regulation.

“The SwRI aggregation system manages charging for a fleet of electric vehicles, while also analyzing grid frequency on a continual basis,” said SwRI’s Sean Mitchem. “When grid frequency drops below an ERCOT-determined set point, our system automatically stops charging some vehicles, removing load from the grid and allowing frequency to return to normal ranges.”

The new system is part of an ERCOT pilot program for Fast Response Regulation Services (FRRS), which are designed to respond nearly instantaneously to grid events, much faster than current frequency regulation services can. EV batteries can respond in milliseconds, making them a perfect asset for FRRS services.

“ERCOT qualification is an important step for this program,” said Mitchem. “Being qualified means that the fleet owner can bid energy services regularly into the ERCOT market and get paid for those services. The fleet owner is now able to take advantage of the normal vehicle downtime to generate additional revenue by making stored energy available to the grid.”

Source: Southwest Research Institute