IEEE Electrification Magazine - June 2014 - 11

PEVs can charge while over wireless charging transmission plates on e-roadways. (Image
by NREL.)

freight routes and the heavy-duty vehicles that currently
account for more than 20% of U.s. fuel consumption.
Unfortunately, the power drawn by electric-drive vehicle
charging times would likely align with peak grid demand,
with 50% market penetration of WPt-equipped Pevs adding

100
80
Total Distance (%)

stations can be far apart once drivers get on the road. if
drivers are able to automatically recharge, it eliminates
the fear that they might be stranded by a depleted battery.
WPt can use an electromagnetic field to transmit power
from the grid to Pev batteries without the use of wires,
cords, or plugs. vehicles are recharged using power from the
grid simply by parking or driving over a charging plate
embedded in the pavement. in the near term, WPt stationary technology can provide a more convenient charging
option. in the long term, a WPt system of electrified roadways could fully automate Pev charging, eliminating driver
range anxiety and extending electrified driving miles.
in addition to addressing the significant consumer barrier of range anxiety, WPt actually gives Pevs the edge
over conventional gas-powered vehicles in terms of fueling convenience. although an extensive network of electrified roadways might be decades from deployment, even
near-term stationary Pev charging in parking lots and
pull-on stations offers drivers greater flexibility in fueling
up. WPt would also enable Pevs to use smaller, lessexpensive batteries, delivering greater electrified range,
allowing plug-in hybrids to spend more time in electrified
mode, reducing vehicle cost, and improving energy efficiency and performance.
the major impediments facing the deployment of this
technology are cost (in excess of Us$1 million per mile)
and integration with the overall transportation system
design. some of those challenges could be ameliorated by
the fact that a small fraction of roadways accounts for the
majority of vehicular travel.
a recent nreL study showed that even without further
battery price reductions, electric roadway-capable vehicles
begin gaining significant market share when a relatively small
percentage of roadways are electrified. as illustrated in
Figure 2, the electrification of 5% of roadways has the potential
to capture about 45% of travel demand, and 1% of roadways
align closely with highly used interstate highways. interstate
electrification may offer the ability to travel to almost any
region in the country by electrified highway. the electrification
of interstates also provides the advantage of serving major

60
40

California
Atlanta
Chicago
Kansas City
San Antonio

20
0

40
60
Roads Traveled (%)

100

Figure 2. An analysis of real-world driving data from travel surveys in
several U.S. locations shows that a relatively small fraction of roads
supports a large percentage of the total distance traveled. (Source: NREL.)

A new NHTSA initiative focuses on the safety benefits on vehicle automation. (Image courtesy of the U.S. Department of Transportation.)

IEEE Electrific ation Magazine / j une 2 0 1 4

Table of Contents for the Digital Edition of IEEE Electrification Magazine - June 2014