Ensuring electric vehicle charger reliability is critical as we aim to significantly ramp up charger deployment through the National Electric Vehicle Infrastructure (NEVI) program. Likewise, identifying ways to measure reliability and performance of EV chargers is equally as important to ensure successful deployment, which we’ve previously discussed in a previous digest.

This past June, my colleagues teamed up with the National Association of State Energy Officials (NASEO) and the American Association of State Highway and Transportation Officials (AASHTO) to convene an online charette focused on evaluating EV charger reliability and performance. A suite of stakeholders across a number of sectors invested in EV charging participated in the charette, including state and federal government agencies, utilities, and consulting firms.

The goal of the charette was to work towards identifying processes for measuring, verifying, and evaluating charger reliability and performance, and my colleagues Kelsey Blongewicz, James Di Filippo, and Sophie Latham summed up the findings in a summary report. Below are four main themes that emerged from the charette discussions.

  1. While obtaining data on charger performance is feasible, a standard methodology needs to be developed to ensure that performance data can be clearly and consistently reported in a summary format. According to information gathered from participants, previous reporting efforts have consolidated power delivery messages into summary measures on peak power use. However, a metric that compares vehicle-requested power to provided power and power capacity is necessary to adequately measure charger performance.

  2. Award recipients of EV charging projects should be responsible for calculating and reporting uptime according to the NEVI program guidance. In addition, states should adopt adequate data verification methods when it comes to reporting charger uptime.

  3. Driver feedback on charger performance, especially in regard to the physical condition of the station, is useful, but should be approached with caution as it is self-reported. The report suggests that self-reported driver feedback is most useful in the aggregate (versus one-off reports), and that user education is necessary for non-technical audiences “to understand the difference between potential power output of the charger and what the vehicle is receiving.”

  4. When reporting data, a consistent and standard specification is critical as a means to save costs. Participants discussed that charging networks and other providers do not want to create multiple reports based on specific state requirements, and that programs should consider adopting a data collection and processing standard, such as Atlas’ EV Charging Use Data Specification.  

View the full report here.

About the author: Moe Khatib