Because so few car models of the type are on the road yet, the ratio of electric vehicles to charging stations is healthy. Whether the ratio stays in balance remains to be seen.
A General Motors engineer who is in the thick of the matter believes that the good progress to date in development of a charging infrastructure owes heavily to standardization of the plug and in-vehicle receptacle that EV owners will use for charging. The engineer, Gery Kissel, is Chair of an SAE International task force that wrote and recently published J1772, the connector standard to be used in the U.S. and, he hopes, in many other places around the world.
“We’re just seeing an explosion of EVSE [electric vehicle supply equipment] infrastructure projects going in,” he told AEI. “You seem to hear about a different project being announced every day—in cooperation with certain cities, very frequently. I don’t think any of that could have been done unless we had the standard in place. It’s having an impact I didn’t quite foresee, and it’s given people opportunity to do things a little bit quicker than what may have been previously anticipated.”
The J1772 coupler (includes the plug and the vehicle receptacle) currently addresses Level 1 (120 V) and Level 2 (240 V) charging. The standard is also used in Korea and in Japan, where several EVs from major automakers already are on sale. J1772 accommodates any country’s electrical system, said Kissel, whose title at GM is Engineering Specialist, RSS Charging Systems, Charging Codes, Standards, and Infrastructure.
He noted that China has come out with its own coupler standards, at least for now as the country carries out EV fleet demonstrations. “I’ve been starting to have very good dialogue with China and trying to harmonize [our standards] as we go forward,” Kissel said.
The group in Europe that is working on a connector standard is the IEC (International Electrotechnical Committee). Its proposed IEC62196 has three specifications, according to Kissel, and is expected to be adopted next fall. One specification is the same as J1772, with the others accounting for differing requirements among European countries, including availability in some of three-phase electricity for fast charging.
SAE hopes J1772 becomes the main global standard for all types of charging. Kissel said that some European OEMs are incorporating the J1772 specifications into their EV designs because the standard is well established. He noted that J1772 is a good solution for Europe because there is no other established standard there and because there are no “completed production tools” for the proposed IEC connectors, “where with the SAE standard, you can actually go out and buy the [Level 1 and 2] connector and plug-in receptacle today.”
But it’s not clear that J1772 will win out. Richard Lowenthal, CEO of charging station maker Coulomb, said his company’s biggest client is the city of Amsterdam, whose 120 stations will be equipped with something other than a J1772 connector. “In the U.S., everyone pretty much wants J1772. The story is over,” he said. “In Europe, not so much.”
However things pan out in Europe, at least the J1772 physical interfaces and communication protocols will be the same between the SAE and IEC plugs, said Kissel. The main difference would be in the plastic housing.
Kissel noted that Europe hopes to move from the three couplers in the current draft standard to a single one by 2017.
Also unresolved in terms of global harmonization is a standard for fast charging. Only in Japan is such a standard in place. Kissel said his J1772 task force is working feverishly to develop a dc fast-charging standard. Most of his task force members want to see J1772 updated so a single plug can accommodate both dc fast charging and the slower ac charging of Level 1 and 2, Kissel said, “but it’s a very big challenge.” He noted that pins would have to be added to the current five-pin J1772 plug, and as a consequence it would have to be larger.
The task force is also considering how to incorporate features of, or perhaps outright adopt, the Japanese fast-charge standard. Either way, the goal is to have one plug for all types of charging so vehicles need not be designed with two space-eating receptacles, Kissel said.
Coulomb and ECOtality are developing dc fast chargers, and the latter will be installing such units as part of its EV Project. But Level 2 is where the real action is in the short term.