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Brief Description of my presentation IMPACTS ASSESSMENT OF PLUG-IN HYBRID VEHICLES ON ELECTRIC UTILITIES
AND REGIONAL U.S. POWER GRIDS
PART 1: TECHNICAL ANALYSIS



Michael Kintner-Meyer
Kevin Schneider
Robert Pratt
Pacific Northwest National Laboratory
(a)


ABSTRACT


The U.S. electric power infrastructure is a strategic national asset that is underutilized most of the time.
With the proper changes in the operational paradigm, it could generate and deliver the necessary energy
to fuel the majority of the U.S. light duty vehicle fleet. In doing so, it would reduce greenhouse gas
emissions, improve the economics of the electricity industry, and reduce the U.S. dependency on foreign
oil. Two companion papers investigate the technical potential and economic impacts of using the
existing idle capacity of the electric infrastructure in conjunction with the emerging plug-in hybrid
electric vehicle (PHEV) technology to meet the majority of the daily energy needs of the U.S. LDV
fleet.

This initial paper estimates the regional percentages of the energy requirements for the U.S. LDV stock
that could be supported by the existing infrastructure, based on the 12 modified North American Electric
Reliability Council (NERC) regions, as of 2002, and taking into account congestion in regional
transmission and distribution systems. For the United States as a whole, 84% of U.S. cars, pickup trucks
and sport utility vehicles (SUVs) could be supported by the existing infrastructure, although the local
percentages vary by region. Using the light duty vehicle fleet (LDV) classification, that includes cars,
pickup trucks, SUVs, and vans, the technical potential is 73%. This has a gasoline displacement
potential of 6.5 million barrels of oil equivalent per day, or 52% of the nations oil imports. The paper
also discusses the impact on overall emissions of criteria gases and greenhouse gases as a result of
shifting emissions from millions of individual vehicles to a relatively few number of power plants.
Overall, PHEVs reduce greenhouse gas emissions with regional variations dependent on the local
generation mix. Total NO
X
emissions may or may not increase, dependent on the utilization of coal
generation in the region. Total SO
X
emissions increase in all but 3 regions. Particulate emissions
increase in 8 of the 12 regions. The emissions in urban areas are found to improve across all pollutants
and regions as the emission sources shift from million of tailpipes to a small number of large power
plants in less-populated areas. This paper concludes with a discussion about grid impacts as a result of
the PHEV load as well as the likely impacts on the plant and technology mix of future generation
capacity expansions.

The second paper (Part II: Economic Assessment) discusses the economics of the new PHEV load from
the perspective of a load-serving entity. It discusses the potential downward pressure on rates as
revenues increase in the absence of new investments for generation, transmission, and distribution.
(a)
Operated for the U.S. Department of Energy by Battelle Memorial Institute under Contract DE-AC05-76RL01830

1

INTRODUCTION
The U.S. electric infrastructure is designed to meet the highest expected demand for power and, as a
result, is underutilized the majority of the time. The system operates at its full capacity only a few
hundred hours a year, at most (about 5% of the time). For the remainder of the time, the power system
could generate and deliver a substantial amount of energy needed to fuel the nations light duty vehicle
fleet (LDV): cars, pickup trucks, sport utility vehicles (SUVs), and vans. This paper estimates the
percentage of the U.S. LDV fleet that could be supplied with energy from the existing U.S. power
system without additional investments in generation, transmission, and distribution (T&D) capacities.
This paper postulates an electric-vehicle scenario that is based on the concept of plug-in a hybrid electric
vehicle (PHEV). A PHEV is a hybrid electric vehicle with additional battery-storage capacity sized to
satisfy the daily average driving requirements (33 miles per day), solely on electricity. The battery is
charged with electricity from the electric grid during off-peak hours, most of which occur during the
night. Driving beyond the daily driving range (i.e., long distances) requires that the PHEVs gasoline
engine be used. The analysis of this paper determines the upper limit of the PHEV penetration without
requiring new investment in generation and T&D capacity expansions. The fundamental approach used
is equally valid for a pure electric vehicle with similar electric performances of a PHEV.

In this paper, we frame the discussion by first describing the methodological approach for estimating the
existing idle generation capacity to be used for PHEV charging and then comparing the resulting
generation figure (in MWh) to the energy requirements of the U.S. LDV fleet for daily driving. The
resulting percentage of the LDV fleet constitutes the upper limit of the electrification potential for the
LDV fleet, displacing gasoline fuel with electricity. We presume that the transmission and distribution
system would be capable of delivering the electricity to the new PHEV load and present the rationale for
this assumption. Assuming that the upper limit of the technical-fuel-displacement potential would
occur, we discuss the question of what are the net impacts to the overall emissions as the emission
source shifts from millions of vehicle tailpipes to a smaller number of large power plants. There are
favorable economic impacts associated with a high fuel-displacement scenario. PHEVs provide power
sales revenues without requiring additional new infrastructure. This translates into additional profits
and, from a regulated electricity industry point of view, downward pressure on rates. The economics
from both the electricity providers and the customers point of view are presented in the companion
paper (Part II: Economic Assessment).

BACKGROUND
In his 2006 State of the Union address,
1
President George W. Bush identified the U.S. dependency on
foreign oil as a major national security issue. In the United States, transportation is the largest consumer
of petroleum products of any economic sector. As a consequence, cars, vans, and light duty trucks are a
logical target for alternative fuel supplies. High oil prices during 2005, exacerbated by the supply
disruption in gasoline products in the aftermath of hurricanes Katrina and Rita, brought concerns about
the supply of petroleum to the attention of the public.


1
State of the Union Address available at
http://www.whitehouse.gov/
.

2 These events have increased efforts to identify options to petroleum, including biofuels and hydrogen.
For the reasons noted by the President and national security experts, the faster the United States can
reduce reliance on petroleum, the better. Rapid transition to new alternative fuels will require
significant investment in new fuel production and distribution infrastructure. This is not the case for
PHEVs, as the necessary charging infrastructure is already in place. As new alternative fuels enter the
market, they can be used in PHEVs to further reduce the need for imported petroleum products.


METHODOLOGICAL APPROACH
The study is divided into two analytical components. The first is an analysis of the upper limit of PHEV
penetration using off-peak power for charging the battery. The second is an analysis that assesses the
impacts on the overall emissions as electricity displaces gasoline in the LDV fleet.

We used a conservative approach to identify the maximum utilization of PHEVs by restricting our
analysis on the existing electric infrastructure. In other words, this is a worst-case scenario that does not
include expansion of generation and T&D capacity as PHEVs make inroads into the market place,
increase the electric load, and alter the load shape. Because we do not know when and at what rate
PHEVs may penetrate the market, nor do utility planners, constraining our analysis to the current power
system infrastructure