POWER October 2014 - 36

OPERATIONS & MAINTENANCE
Prepare Your Coal Plant for Cold
Weather Operations
Cold temperatures can be dangerous for personnel and often cause havoc for
power plant equipment. Suitable preparation can mean the difference between
a quiet shift and a nail-biting struggle.
Aaron Larson
C
old temperatures are nothing new, but
extreme winter weather has been in
the headlines more and more in recent
years. Many of us had never heard the term
" polar vortex " before last winter, but earlier
this year it seemed as if the Arctic polar
vortex was dipping down into the U.S. on a
regular basis.
For coal-fired power plants, changing
seasons bring a variety of challenges. Cold
weather, snow, and ice each cause different
problems. Coal deliveries via rail can be delayed
due to train tracks being impassable as
a result of winter storms. Once a train does
arrive, frozen fuel can result in a large portion
of the delivery being stuck inside the
cars. When temperatures remain below zero
for weeks on end, the problem can be nearly
impossible to prevent.
Design Sets the Stage
Basin Electric Power Cooperative is one of
the largest electric cooperatives in the U.S.
The company's core business is generating
and transmitting wholesale bulk electric
power primarily to its 137 member rural electric
systems, which are located in nine states:
Colorado, Iowa, Minnesota, Montana, Nebraska,
New Mexico, North Dakota, South
Dakota, and Wyoming.
Basin Electric gets about 60% of its nearly 4
GW of owned generation capacity from coalfired
power plants located mainly in North
Dakota and Wyoming. Its first power plant-
the 222-MW Leland Olds Unit 1 located near
Stanton, N.D.-went online in January 1966
and was the largest lignite-based power plant
in the Western Hemisphere at the time.
" We learned a lot from the facility in the
early years, " John Jacobs, vice president of
operations for Basin Electric told POWER.
" Most of our design specifications were developed
as a result of lessons learned at the
Leland Olds Station. Contracts now call for
control between -40F and 120F. We are very
diligent in ensuring that those climate extremes
are met. "
36
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POWER | October 2014
Heavier insulation, larger heating systems,
and heat trace-use of an electrical
heating element in direct contact with a
component-can be added to protect against
freezing temperatures in cold weather climates.
But even when the proper design
parameters are met, trouble can still arise.
Basin Electric has learned where weak
points exist through experience. The company
uses its computer-driven preventive
maintenance system to queue up projects
and manage preparations.
" Once one winter is complete, we begin
working on the next winter's projects during
the spring and summer, " said Jacobs. " Heat
trace, insulation, siding, it runs the gamut of
anything that might affect you that you've
found out from the previous year. You put
in work requests for those that come up year
after year. Of course, you want to get those
done when the weather is warm, so people
don't have to fight the extreme cold during
the winter months. "
Xcel Energy performs a similar procedure.
Each year its power plants review, update,
and perform winterizing preparation
tasks in accordance with a procedure and
checklist. The checklist follows the North
American Electric Reliability Corp. winterization
guidelines (developed in response to
rolling blackouts and natural gas delivery
interruptions experienced in the Southwest
in February 2011) and also has a section for
plant-specific tasks. The company's preventive
maintenance crews regularly check all
winter protection items, such as heat trace,
1. Heavy duty slider. Sliding doors hold up better in windy conditions. Courtesy: Tucson
Electric Power (TEP)
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POWER October 2014

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