This Small Business Innovation Research (SBIR) Phase I project will determine the feasibility of integrating existing grid-tied solar inverters with the emerging fleet of electric vehicle storage batteries as a low-cost pathway to the electric transportation energy supply of the future, and to create financial incentives for both electric vehicle and solar energy owners. The proposed project will demonstrate hardware and communications software to couple an existing grid-tied solar inverter and an existing electric vehicle battery and charger to signals from the local Independent System Operator (ISO). The alternative proposed here, which can enable V2G operation for any vehicle equipped with a DC charging port quickly and inexpensively, is to link the inverter either directly to the vehicle battery or through a low-cost ($300/kW) DC-DC converter, along with the existing vehicle charger, to perform this service. The inverter is not currently used during the hours of darkness, and the vehicle is available for charging at night using low-cost off-peak power. Success with this alternative could lead quickly to a network of grid-tied vehicles providing ancillary services during the nighttime hours and utilizing expensive vehicle batteries and solar inverters more effectively than at present.
The broader impact/commercial potential of this project results from the emergence of electric vehicles in large numbers and of web-based communication and control technology. This presents a unique opportunity to integrate the energy supply for personal transportation with the electric utility system to create a distributed, remotely-dispatchable electric-power storage capacity. This capacity can provide valuable ancillary services for frequency regulation, synchronized (spinning) reserve and demand management for improved grid stability and capacity utilization. Electric power storage capacity is particularly relevant in relation to renewable power generation, which is uncontrollable due to its dependence on the wind and the sun. At the same time, the revenue from these services can provide an incentive to the owners of electric vehicles by realizing the latent value of their large and expensive electric storage batteries, and to the owners of solar energy systems. Focusing only on frequency regulation, there is an existing nationwide market of approximately $1.8 billion per year for services that electric vehicle batteries can provide better than existing power plants. A technology and a business model are needed for an aggregator to stand between the individual vehicle owners and the ISOs who require the service. Demonstration of a novel approach to this technology with existing vehicles at the Penn State GridSTAR facility in Philadelphia, PA, is the objective of this Phase I project.
