This piece was originally published in the May/June 2019 issue of electroindustry.
Andrei Moldoveanu, Technical Director, NEMA
On today’s roads, good things are moving fast and multi- directionally. A spark anywhere triggers others in expected and unexpected places. Tesla ignited the current electric vehicle (EV) spark in 2008 with its Roadster, which in turn enabled subsequent models. The very idea got people so excited about a mass-produced and competitively priced EV that more than 400,000 customers paid $1,000 each to reserve one that would be delivered at an undefined future date.
The spark ignited the auto industry at large with nearly every major automaker introducing EVs or new hybrid models. Several countries even committed to eliminating internal combustion engines in cars by 2040.
Since EVs work on batteries, the charging equipment industry became fundamental to successful EV adoption. It started small with chargers that plugged into regular household receptacles and took all night for the battery to charge. The next move was to improve the speed by plugging the EV supply equipment (EVSE) into beefed-up dedicated branch circuits. While charging the EVSE in four to six hours seems reasonable in one’s garage, waiting that long while on the road was not. Faster charging speeds became the next goal.
A new charger iteration, the direct current fast charger (DCFC), does a good job topping off a battery, but a full charge still needs about an hour. And technologies continue to evolve so that more electricity can be “pumped” into the vehicle faster, bringing the charging time to as little as 10 minutes. The problem now, however, is that the battery and the car’s electrical distribution system need to handle that amount of power. We can expect more iterative improvement for the foreseeable future.
Many Roads to Travel
The EV spark also triggered a revolution in batteries. The cost of the basic EV lithium-ion battery decreased by 80 percent in fewer than ten years, and this trend is likely to continue as the result of a relentless push to improve charging speed and storage capacity parameters.
Since volume drives down price, we may end up with more batteries than the EV industry alone needs. Far from being a problem, excess batteries can be used as energy storage to help fast-charge an EV, thus relieving stress on the grid. These batteries can also help the grid when renewable energy sources (i.e., transient sources like solar and wind) are deployed or during demand swings.
Passionate drivers may find the EV’s propulsion potential exciting. In addition, by using four independent motors for the wheels, maneuverability is improved, which is beneficial when there is inclement weather. For other drivers, the prospect of not driving at all is equally attractive and autonomous, driving technology has made extraordinary strides. Despite setbacks, auto-piloted cars have already reached noteworthy safe driving records and the industry is working hard to improve those.
Meanwhile, wireless charging has been struggling to pick up speed. While it uses technologies employed in non-contact charging applications like electric toothbrushes and cellphones, there have been problems. One is the precision of a car positioning itself over an emitting antenna. An autonomous car can mitigate this problem. Once it detects the charger’s antenna, it can position itself perfectly for maximum energy transfer efficiency. This, in turn, solves a huge problem in the smart city of the near future: how self- driving cars can refuel automatically.
EV market penetration may be slow in the eyes of some observers, but 40 percent current annual growth is proof that this transportation spark has started some currents. ei