Vehicle-to-grid (V2G) technology allows electric vehicles to charge and discharge electricity to and from the grid. V2G can improve the power system’s resiliency and reliability and make customers money. Studies have been conducted to understand how V2G service can be implemented, but more are necessary before it becomes widely available.
Vice President Lisa Cagnolatti of Southern California Edison confirmed that electric vehicle batteries are “capable of two-way electricity flow into and out of the power grid. That allows them to go from simply consuming energy to potentially becoming a fully functioning component of the smart grid."
A two-year V2G study was recently completed with Southern California Edison and the California Independent System Operator (CAISO) wholesale electricity market at Los Angeles Air Force Base. The project was funded by the U.S. Department of Defense and the utility is expected to submit a final report with the findings of the program soon.
The demonstration comprised 32 electric and hybrid vehicles, including Nissan Leaf sedans, Ford F-Series trucks and VIA Motors VTRUX vans. The cars provided frequency regulation, which is the constant second-by-second adjustment of power to maintain grid frequency at 60 Hz to ensure stability, to the CAISO wholesale electricity market.
Southern California Edison billed the military base for charging the electric car batteries, and each of these bills included a credit or penalty from CAISO based on how the batteries performed as an energy-storage resource.
The software called On-Base Electric Vehicle Infrastructure, created by the Lawrence Berkeley National Laboratory and Kisensum, enabled the vehicles to participate in this study. The program aided base personnel in reserving and checking out electric vehicles, collecting planned trip departure and return times and tracking vehicle preferences and distances traveled.
The final phase of the V2G project assessed how the electric and hybrid vehicles on base could be used to support critical infrastructure during an emergency. One product that would be particularly helpful during an emergency is Envision Solar International’s Electric Vehicle Autonomous Renewable Charger (EV ARC).
EV ARCs operate with solar power and energy storage and on or off the grid, depending on customer needs. Thus, EV ARCs provide electricity to charge cars even when the grid is down. Because EV ARCs sit above ground, no costly and timely digging and installation is necessary. One EV ARC takes about nine minutes to set up and it can easily be moved from one location to another.
To prevent blackouts and brownouts caused by load spikes, Louisiana Gas and Electric connected their EV ARCs to the grid. Furthermore, New York City purchased $3.8 million EV ARCs to deliver solar powered charging to its electric vehicle fleet.
Providing V2G service to the wholesale market allowed the Los Angeles Air Force Base to earn money to pay for energy and new vehicle costs while enhancing grid reliability simultaneously. In addition, electric vehicles further decrease operational costs because they require less maintenance, saving the military even more money.
A year-long V2G study was also conducted by Nissan, Nuvve and the Italian utility Enel SpA in Denmark. The program confirmed that V2G services can cover some costs related to charging an electric car. In fact, Nissan and Ovo, one of the United Kingdom's largest energy suppliers, will offer V2G service to Nissan Leaf buyers next year.
While Nissan and Ovo are ahead of the curve by providing V2G service, there is some hesitation in the U.S. For instance, automakers want proof that using electric vehicle batteries to store energy will not negatively impact vehicle performance or operating range. Customers also must be willing to pay for extra features that enable V2G service.
At this time, individual automakers develop their own proprietary communications standards for their vehicles. The Electric Power Research Institute is trying to change this by leading a project with various utilities, electric vehicle automakers and regional transmission organizations to create a cloud-based software system called Open Vehicle-Grid Integration Platform.
This system would provide a standardized utility interface with a “universal translator” to communicate with all types of electric vehicles. Such a connection allows electric cars to increase or reduce charging power levels based on grid conditions, send demand response signals and capture billing information.
Southern California Edison’s final report from the Los Angeles Air Force Base program will help inform regulators, utilities and automakers on how to proceed with V2G. Successes and challenges experienced by Nissan’s and Ovo’s V2G service should be carefully examined to create best practices for operating this new technology. Soon, electric vehicles will not only be a method of transportation, but a useful resource for grid stability.
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