Rationale
It’s been over three years since the Maryland Public Service Commission approved an EV charging pilot that allows the utilities to use ratepayer funds to own and operate public charging stations. When they petitioned for approval of the pilot, my utility, BGE, had assured regulators that their public EV charging stations would be highly reliable and that they would respond quickly to resolve outages and issues. How are they doing in that regard? I wanted quantitative data to find out.
95% to 99% uptime is the range described in the utilities’ semi-annual EV charging reports. That seems quite optimistic compared to what other EV drivers and I have experienced. The only way to actually find out the ground truth is to go out and visit the chargers. I chose to evaluate all the utility-owned fast chargers in the BGE service territory.
Professor David Rempel of the University of California, Berkeley recently published a study on the reliability of the public (non-Tesla) electric vehicle fast chargers in the San Francisco Bay Area. The results showed that more than a quarter of the chargers in the Bay Area were not functioning or had a design failure. The non-functioning stations suffered from non-responsive displays, payment system failures, initiation failures, network failures, or damaged connectors.
The Berkeley study utilized a group of volunteer EV drivers who visited the chargers and tested each one by plugging into their EV and attempting to charge for two minutes. The methods used in the Berkeley study inspired the procedure that I used to test the fast chargers in Maryland.
Procedure
Between August 28 and September 6, 2022, I tested all 69 public fast chargers that are owned and operated by BGE. I created a map of the charger locations and divided the locations into manageable groups that I could visit and evaluate over a number of days.
I drove to each site and worked through a checklist of tasks to test each fast charger. First I took a series of photos of the chargers. Then I recorded the Station ID, model and serial number of each unit. I visually inspected the equipment including the display, cables and connectors for damage. I documented the online status of the charger in the Shell Recharge mobile app. Then I attempted to initiate a charge via the app. If the unit began charging, I let it run for two minutes. Meanwhile I took note of the charging speed and made sure that the charger was operating as expected. After two minutes, I’d stop the charge and then attempt to initiate a charge using the RFID card reader.
If a charging session failed, I reported it to Shell Recharge customer service. This should have alerted BGE of the specific chargers that were having issues. In many instances, when I reported the issue, Shell Recharge responded that a service ticket had previously been created.
Results
A charger was classified as fully functional if it authorized via the Shell Recharge app (or started free), initiated a charge, and maintained the expected charging speed for two minutes.
71% (49) of the BGE fast chargers were fully functional as defined above.
14.5% (10) of the chargers were completely inoperable.
2.9% (2) consistently displayed error codes and would not charge.
4.4% (3) were offline and did not respond via the app. However, these did initiate via a tap of a Shell Recharge RFID card. Most drivers however do not carry a Shell Recharge card.
7.2% (5) initiated a charge but delivered very low power, around 15 kW. That is a fraction of the 50 kW rated power for those stations.
Payment Methods
The payment methods tested were the Shell Recharge mobile app and the Shell Recharge RFID card. The BGE chargers do not have functioning credit card readers. The RFID card requires a $5.00 payment and is delivered by mail. Due to the advance arrangements required to acquire an RFID card, I focused mainly on the mobile app to determine payment authentication success.
Physical Access
There were two instances during the evaluation where my access to a charging station was obstructed. The first was a gasoline car that had parked in front of one of the two fast chargers in Chesapeake Beach. The signage at that space read, ELECTRIC VEHICLE PARKING ONLY. A new Maryland law that goes into effect on October 1st would prohibit vehicles from blocking EV charging stations. An important proviso of the statute is that a sign designating that charging space must conform to federal and state standards for parking signs and include the amount of the penalty for violations ($100 fine).
The Whitmore Garage in Annapolis is undergoing renovations that have temporarily routed vehicles through the parking spaces in front of the charging stations. I was able to park close enough to the chargers in both instances to perform a complete evaluation including two minutes of continuous charging. I treated both of these chargers as if they were fully available for the purposes of this evaluation. Both were classified as fully functional.
Follow Up Testing
I revisited 13 chargers that were classified as less than fully functional. I checked if their condition had changed in the days and weeks following the initial visits and reporting of the issues. In every instance, the chargers were still broken.
In order to achieve the forthcoming NEVI standard of 97% uptime on an annual basis, a charger must not be down for more than 11 days. Eight of the revisited chargers have already fallen below the 97% uptime threshold since I began this charger evaluation.
Conclusions
High reliability of public EV charging stations is vital for a positive EV driver experience and to support electric vehicle adoption. The Maryland Public Service Commission’s 2019 EV Order requires that the utilities “be responsible for ensuring that public charging stations are working and maintained in good working order.” It is clear from the data that there is much room for improvement.
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Note: This post was derived from formal written comments to the Maryland Public Service Commission. See the full comments and report in Maillog No. 242263. View the video of the discussion at the 9/14/2022 PSC Administrative Hearing.
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