Following on the heels of the Department of Energy report on
how to implement a network of Fast Chargers for electric vehicles in this
country (see my posting
here), the agency has published a new study detailing
the research and development needed to get to the next generation of chargers:
Extreme Fast Chargers (
Enabling Fast
Charging: A Technology Gap Assessment, available
here).
The authors define Extreme Fast Charging as technology that
would charge an EV in less than 10 minutes with enough “juice” to go 200
miles. This rate of charging
(roughly 20 miles of range for every minute of charging) is far better than the
current best technology (Tesla Superchargers can give you up to 5.6 miles per
minute). At this rate,
long-distance EV travel would no longer impose a time penalty, compared to
internal combustion vehicles. And
we Americans do obsess about our time!
As you might expect, there are lots of engineering problems
involved in designing and deploying an Extreme Fast Charging system. The report lays out all the problems in
detail (be prepared to go deep into the scratchy weeds) with a focus on
batteries, vehicles, and infrastructure.
With regard to infrastructure – my usual space – the report
says that “there is a distinct need to understand how fast charging up to 400
kW will impact the electrical grid, the design of EVSE [chargers], impacts
brought by demand charges, and XFC-related infrastructure costs.” In other words, plenty of R&D work
to be done.
Is it worth it?
The authors note that the deployment of DC Fast Chargers (no one has
convincingly explained to me why we can’t call these Level 3 chargers) has
already had effects on EV travel: “With the emergence of DCFC (up to 50-kW)
capability for Nissan Leafs, it has been observed that longer range trips using
BEVs have occurred in the northwestern portion of the United States. The
ability to use DCFC for longer trips, combined with automotive manufacturers
producing a greater number of BEVs with range above 100 miles, closes the ‘range
anxiety’ gap that exists between ICEVs and BEVs.”
Lots of room for TRB papers!