POWER GENERATION
BY BO SVENSSON
A view from inside the Plains End station, located in the state of Colorado, U.S.A., shows the
Wärtsilä 20V34SG gas engines in operation. The Plains End generating facility is used to bal-
ance Colorado’s 1300 MW of wind power capacity.
Flexible Power
Gas-fired power plant provides quick-start generation to offset varied wind
power output
Wärtsilä has been contracted to supply a 170 MW gas-fired power plant to
be installed in Antelope Station, located
near Abernathy, Texas, U.S.A. The
power plant is to be located close to significant wind farm generation and will
serve to stabilize the grid when the output from the wind farms changes unexpectedly because of weather changes.
Whenever a nondispatchable, volatile wind component is added to the
power generation portfolio, it presents
additional challenges to system operators. Simultaneous grid load and wind
power changes must be managed, and
thermal power plants need to be
ramped up and down more rapidly and
frequently. The use of wind power
leads to more frequent starts and stops,
but also reduces the average load of the
thermal plant.
“With an increasing wind capacity
allotment, the grid stability cannot be
ensured merely by grid codes and
transmission grid strengthening,” said
Frank Donnelly, president of Wärtsilä
North America Inc. “As the existing
thermal power plants were not origi-
nally designed for frequent starting and
load changes, new flexible and dynam-
ic capacity is needed. These power
plants are to be located close to signifi-
cant wind farm generation serving to
stabilize the grid. And here we see the
role of Wärtsilä’s power plants.”
The contract for this new power plant
was signed in November 2009 with
Golden Spread Electric Cooperative
Inc. (GSEC), a consumer-owned public
utility providing power to 16 member
distribution cooperatives, which serves
208 000 retail consumers.
“We are thrilled to be selected by
Golden Spread and to be bringing
more Wärtsilä flexible power to Texas.
The quick-start and rapid response
characteristics of this plant will assist in
ensuring high grid reliability while providing competitive energy to GSEC
members,” said Donnelly.
The new power plant will incorporate 18 Wärtsilä 20V34SG generating
sets, along with mechanical, electrical
and control auxiliaries, switchgear and
exhaust emission controls. Additionally, Wärtsilä will provide installation
and commissioning support, as well as
factory training.
The power plant is expected to
achieve commercial operation in early
2011. The approximately 170 MW
produced by the plant will be enough
to meet the peak load requirements of
55 000 homes.
“A primary reason for selecting our
technology is its ‘quick-start’ capabili-
ty. The engines are designed to achieve
full operation in less than 10 minutes,
whereas traditional gas-fired genera-
tion can take from one to four hours to
start,” said Donnelly. “Wärtsilä’s natur-
al gas fuel technology has the capabili-
ty to operate efficiently at low loads;
a capability that can be used for pro-
viding a ‘spinning reserve’ capacity for
the system.”
Wind generation output varies ac-
cording to wind speed. Reductions in
wind generation output must be offset
immediately by a corresponding increase
in output from other generators.
“The growing summer electricity
demand and the large amount of wind
generation located in the region were
main drivers in GSEC’s choice of
quick-start generation technology,”
said Mark W. Schwirtz, president and
GM of the generation cooperative.
“Quick-start generation works well
in meeting this type of electricity supply requirement. The new units are
also fuel efficient and use almost no
water,” Schwirtz continued. “
Additionally, by adding 18 separate units,
Golden Spread reduces its risk from
unit failures.” A
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