Key Performance Indicators for Vehicle Grid Integration

Electric vehicle (EV) sales account for a rapidly growing portion of the light-duty vehicle market and a portion of medium and heavy-duty fleet vehicles. The charging station network to support those vehicles is growing as well. However, in many locations, charging stations will require costly utility grid upgrades with long lead times. Also, growing charging demand for electricity has the potential to negatively impact the electric grid. To prevent these adverse impacts, it is crucial for the EV charging industry to seamlessly integrate EV charging with the grid. The industry is in the early stages of this process, known as vehicle grid integration (VGI). Today, there are a few methods of smart charge management (SCM), which can reduce the costs and wait times for electric vehicle supply equipment (EVSE) interconnection approvals, as well as reduce the impacts of the charging stations on the grid and potentially lower costs for EV drivers and ratepayers alike. To make systematic improvements, EV charging industry and utility industry stakeholders need to define and measure VGI impacts. Many stakeholders currently measure specific aspects or individual connections that facilitate VGI, but they typically do not examine end-to-end connectivity or use overarching customer-facing metrics, such as EVSE uptime, which make targeted improvement difficult. High charging station and communications reliability is required for successful VGI projects, especially with regards to enabling SCM. Industry practitioners need granular metrics to know the performance of specific connections and interfaces and what data are needed to evaluate those metrics. This report defines such metrics, and they are referred to as key performance indicators (KPIs).