IEEE Electrification Magazine - June 2014 - 12

roughly 10% to the existing energy demand. When combined with the expected growth of renewable generation
and the connectivity benefits of automated vehicles (avs),
however, the option of electrified roadways may offer a crucial key to truly green transportation.

Declaring Independence:
Automated Vehicles

xx
location of open parking spots
xx
alignment with wireless charging devices
xx
identification of nearby charging stations.

collectively, these capabilities will result in less congestion, shorter trips, reduced aerodynamic drag, and more
efficient use of charging infrastructure, all of which contribute to energy savings and reduction of
carbon dioxide emissions. Based on
nreL's analysis, the overall energy savings resulting from these new features
could range from 10% to 15%. even
fairly simple forms of automation,
such as green routing (selecting the
least congested, most energy-efficient
route using a global positioning system; see Figure 3) and hev mode
scheduling (shifting from gas to electricity based on route-connected information) are capable of increasing
vehicle energy efficiency by 3-5%.
these same av capabilities can
also encourage the adoption of electric-drive vehicles. automated charging can dramatically lessen range
anxiety. other automated features
allow drivers to act more like passengers, freeing them up from decision
making or even navigation, relieving them of the stress
of driving, and potentially allowing them to become
more productive en route.
although vehicles with limited automated features are
already on the roads, and automakers including BMW, Ford,
GM, toyota, nissan, volvo, and audi have showcased selfdriving prototypes, full automation is still in its infancy.

Combining PEVs
with clean electricity
generated from
renewable sources,
such as solar
photovoltaic arrays
and wind turbines,
offers the greatest
near-term potential
for net-zero energy
transportation.

self-driving or fully avs are rapidly
moving from the realm of science
fiction to the forefront of real-world
transportation technology, with
many automakers already offering
vehicles with some automation, such
as popular parking-assistance and
collision-avoidance features. in addition to these safety and convenience
benefits, av technology has the
potential for significant impact on
transportation energy use and
Pev adoption.
the national highway traffic safety administration (nhtsa) launched
a new vehicle-to-vehicle (v2v)
communication technology initiative in
February 2014. even before the
announcement, market penetration of
connected vehicles was projected to increase by 80% in the
United states by 2017. the nhtsa initiative focuses primarily
on crash aversion safety enhancements provided by v2v
communication, but it also recognizes the potential for energy efficiency benefits. these include automated
xx
selection of the most efficient driving routes
xx
smoother starts, stops, and accelerations
xx
coordination of speeds with traffic signal timing
xx
speed control and braking, allowing vehicles to travel
closer together in platoons

Route
Distance, miles
Duration, minutes
Average Elec Rate,
Wh/mi*

A
81.6
107

B
76.2
107

C
67.6
113

0.83

0.89

1.0

Average mi/gal*

0.45

0.50

1.0

Cost, US$*

1.0

0.89

0.59

(*Normalized Values)
Automated speed control and braking make it possible for cars to
travel closer together, reducing congestion and improving energy efficiency. (Image courtesy of the U.S. Department of Transportation.)

I E E E E l e c t r i f i c ati o n M agaz ine / j un e 2014

Figure 3. An example of the energy and cost savings possible
through green routing. (Source: NREL.)

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