http://www.xcelenergy.com
February 21, 2007 11:41 AM Eastern Time
Xcel Energy Study: with a Smart Grid, Plug-in Hybrid Electric Vehicles
Could Have System Benefits

DENVER--(BUSINESS WIRE)--Xcel Energy today announced the results of a
six-month study related to plug-in hybrid electric vehicles (PHEVs)
and how an increase in their popularity may affect Colorado. The study
found that PHEVs may result in a reduction of the overall expense of
owning a vehicle and, with the help of smart-grid technologies,
eliminate harmful vehicle emissions by up to 50 percent.

The study looked at how adding PHEVs to the road could affect the
electric power grid depending on when and where the cars were
charging. It also looked at the overall emission footprint of these
vehicles, the decreased vehicle fuel costs and how PHEVs could impact
the company's production and capacity costs.

Xcel Energy's Utility Innovations group worked with the U.S.
Department of Energy's National Renewable Energy Laboratory (NREL) on
the study. A cutting-edge computer-modeling program was used to
measure the impact of a mass penetration of PHEVs and how much energy
would be required to charge them.

NREL's program was able to simulate adding vehicles to the roads in
large increments, under real driving conditions, simulating an
increase in the market penetration of these vehicles. The study
revealed that these cars, each equipped with a 9 kilowatt-hour
battery, could reduce overall CO2 vehicles emissions by half. They
could also save owners more than $450 in fuel costs each year compared
to a traditional combustion engine vehicle.

"Hybrid gas/electric vehicles are already on the market and PHEVs are
staged for growth, so we wanted to know how that could affect our
business," said Mike Carlson, CIO, Xcel Energy. "Depending on when
customers choose to recharge, adding PHEVs to the road may help reduce
overall emissions of CO2 without significant increases in utility
infrastructure. In other words, PHEVs could be one piece of the puzzle
to solving our global climate change problem."

How much would be saved in vehicle emissions depends on when drivers
charge their cars. Incentive programs may induce customers to charge
their PHEVs at certain times and will help Xcel Energy minimize
emissions and operating costs as well as incremental utility
infrastructure investment. "Successfully managing a charging program
will depend on a smart utility grid," said Ray Gogel, chief
administrative officer for Xcel Energy. "This study is one step we are
taking to demonstrate how to use energy more efficiently through
smart-grid technologies. In order to make a dent in issues like
climate change and dependence on foreign oil, the grid must change.
Plug-in hybrid electric vehicles have the potential to help us better
use renewable and other nontraditional energy sources while creating a
grid that is more interconnected, balanced and reliable."

Plans are in place to work towards a more intelligent utility grid.
While the specific impact has yet to be studied, technology already
exists to allow customers to feed excess power from their own PHEV,
back onto the grid. This can potentially lead to better use of
renewable energy sources and improved reliability. Future studies will
include PHEV field tests and evaluate the ability to manage the
charging process in conjunction with the availability of renewable
energy sources.

Xcel Energy (NYSE: XEL) is a major U.S. electricity and natural gas
company with regulated operations in eight Western and Midwestern
states. Xcel Energy provides a comprehensive portfolio of
energy-related products and services to 3.3 million electricity
customers and 1.8 million natural gas customers through its regulated
operating companies. Company headquarters are located in Minneapolis.
More information is available at www.xcelenergy.com.

NREL is the U.S. Department of Energy's primary national laboratory
for renewable energy and energy efficiency research and development.
NREL is operated for DOE by Midwest Research Institute and Battelle.
Contacts

Xcel Energy
Media Relations, 303-294-2300
www.xcelenergy.com
or
NREL
George Douglas, 303-275-4096
George_Douglas@...