The City of Newark, Delaware has become the first electric utility in the United States to approve the use of an electric vehicle to store and provide power for the local electric grid.
University of Delaware (UD) researchers led by Associate Professor Willett Kempton developed the Vehicle-to-Grid (V2G) concept in collaboration with a consortium (MAGIC, Mid-Atlantic Grid Interactive Cars Consortium) of industry partners over the past decade to establish the communications protocol between the vehicle and the grid operator. (Earlier post.) Industry partners in the consortium include Delmarva Power and its parent company Pepco Holdings Inc; PJM, the regional grid operator; California-based electric vehicle manufacturer AC Propulsion; and others.
With the City of Newark’s approval, the UD team is now conducting V2G testing at two outlets within the City’s service territory.
Currently, there is no energy storage built into the electric grid system; electricity usage and electricity generation must be simultaneous. While V2G is expected to have several applications, according to a report by MAGIC published in November 2008, the most economic entry currently is the market for ancillary services (A/S). The highest value A/S is frequency regulation (in many ISOs, including PJM, this service is simply called “regulation”). In areas with deregulated electricity markets, regulation can have average values of $30-$45/MW per hour, with hourly rates fluctuating widely around that average.
A second market of interest is spinning reserves, or synchronous reserves, with values in the range of $10/MW per hour, but much less frequent dispatch.
The primary revenue in both of these markets is for capacity rather than energy, and both markets are well suited for batteries as a storage resource because they require quick response times yet low total energy demand. Additionally, V2G can provide distribution system support when there is a concentration of parked V2G cars, along overload elements in the distribution system.—MAGIC 2008
As fluctuating, non-dispatchable renewable sources, such as solar and wind power, become a larger component of electric generation—and “when parked V2G-capable cars are connected and aggregated in large numbers“—V2G energy storage could help grid operators smooth power output fluctuations.
Wind tends to blow stronger at night when the electric load is low. If electric vehicles charged at night with wind power, the grid operator could use the energy in the batteries, when vehicles aren’t needed for driving and are plugged in, to help maintain grid reliability. The vehicle owner would then be paid for providing these energy services at a greater value than what they paid for the electricity.—Willett Kempton
The City of Newark’s Electric Department initially rejected the car (an AC Propulsion eBox EV modified by adding controls and logic to make it respond to the PJM real-time signal for regulation) until testing was done by the National Renewable Energy Laboratory to the same standards as photovoltaic systems for anti-islanding. Anti-islanding describes how equipment prevents back feed by isolating generation from the electric grid in the event of an outage, thereby protecting workers servicing the lines.
Solar PV systems and V2G vehicles are tested to the same standards and treated the same within the city’s approval process because electricity from the car’s batteries or from a solar panel is indistinguishable to the electric grid and presents the same potential safety risks to linemen.—Sam Sneeringer, the City’s Assistant Electric Director
Willett Kempton and his team of researchers plan on having a fleet of six vehicles by the end of 2009, two at UD and four operated by the state of Delaware. The test fleet will be used to demonstrate multiple V2G vehicles working together and supplying energy as a single power plant.
The City of Newark, Delaware operates its own electric utility to provide electric services to approximately 11,000 commercial and residential customers within the city limits. It purchases power on the wholesale Power Market. Several outgoing distribution circuits at 12,470 or 4,160 volts distribute power throughout the city.
Supporting Delaware’s Clean Energy Business Community Work Group Report to the Governor’s Energy Advisory Council
A Test of Vehicle-to-Grid (V2G) for Energy Storage and Frequency Regulation in the PJM System (MAGIC November 2008, updated January 2009)