POWER August 2010 - 8

High-Efficiency Gas Turbines Go to Market
This May, following two years of construction, Siemens Energy
put into operation Irsching 5, an 847-MW advanced combinedcycle
power plant near Ingolstadt, Germany. The plant's owner,
Gemeinschaftskraftwerke Irsching GmbH-a joint venture of
E.ON, Mainova, and HEAG Südhessische Energie-features two
SGT5-4000F gas turbines, one SST5-5000 steam turbine, three
hydrogen-cooled generators, electrical systems, and Siemens'
SPPA-T3000 instrumentation and control system.
The plant is designed for 250 starts annually and reaches full output
in just 30 minutes to meet grid requirements for the integration
of wind power, Siemens said. The plant's F-class gas turbine technology
and quadruple-flow low-pressure steam turbine pushes its efficiency
to more than 59.5%. But this isn't the best in Siemens' arsenal
of gas turbines anymore. According to the German company, that
title is reserved for its new 60-Hertz SGT6-8000H gas turbine. Florida
Power & Light will be that model's first customer.
At a press conference this June to mark commercial availability
of the H-class turbine after a nearly decade-long development
phase that took it from prototype to marketing, the company said
it had achieved " a masterpiece of engineering " that sets a worldrecord
efficiency of 60%. It also claims that, compared to solutions
installed at combined-cycle power plants, the new generation of
gas turbines consumes one-third less natural gas and emits onethird
less carbon dioxide. Added to that, while temperatures inside
the combustion chamber reach up to 1,500C, the turbines can go
from standby to start-up in 5 minutes and reach full power operation
in just 15 minutes. " They need only minutes to switch from
full power to half power or vice versa, enabling them to optimally
compensate for natural fluctuations in rapidly increasing grid feedins
from wind and solar energy sources, " the company said.
A brainchild of Siemens and Westinghouse engineers, the Hclass
consists of more than 7,000 individual parts (Figure 1). The
largest model available weighs a stunning 444 metric tons-as
1. In a class of its own. Siemens Energy marked commercial
availability of its SGT6-8000H gas turbine, shown here, this June. The
so-called H-class gas turbine is the result of a nearly decade-long development
phase and is the highest efficiency class currently available,
Siemens says. The SGT5-8000H was tested more than 1,500 hours at
a simple-cycle power plant at Irsching 4 in Bavaria, Germany. Courtesy:
Siemens Energy
much as a fully fueled Airbus A380-and, according to Siemens,
the distance between the blades and the housing is as small as
the thickness of a postcard. The company adds: " Turning at more
than 1,700 kilometers an hour, some parts of the turbine blades
exceed the speed of sound when in operation. "
The H-class turbine is in the " two- to three-digit million [dollar]
range, " yet it already has its first customer-and Siemens
expects to sell at least 10 a year in the medium term. Florida
Power & Light in June signed up for six 60-hertz, 274-MW H-class
turbine generator packages for the modernization of its Riviera
Beach and Cape Canaveral Next Generation Clean Energy Centers
in Florida. The utility said its decision was based on " long-term
strategic decisions " that would comply with stricter anticipated
environmental controls in energy legislation.
The shift to gas-powered generation is gaining speed across
the pond, too, fueled by a recent plunge in natural gas prices,
new shale gas mining, and campaigns against new coal power
plants. In the UK-a country that produced 47% of its power
with natural gas (compared to 34% from coal in 2008)-24 new
gas-powered stations, nearly 29 GW, are under construction or in
the planning process, compared with two planning applications
for new coal plants.
Like Siemens, anticipating increased demand for high-efficiency
gas turbines, UK company Rolls Royce in June rolled out the
H63 (Figure 2), the newest model of its industrial RB211 gas
turbine series. The 44-MW engine can deliver at least 30% more
power than earlier models, Rolls Royce claims, with a thermal
efficiency of up to 41.5% as well as operational flexibility. The
technology builds on Trent aero technology and features highpressure
turbine rotor blades and intermediate compressor stators
and rotors.
2. Dash for gas. Gas-powered generation is gaining ground
against coal in the UK, too, fueled by a recent plunge in natural gas
prices, new shale gas mining, and campaigns against new coal plants.
The growing market prompted Rolls Royce to launch the H63, the latest
addition to a range of industrial gas turbines. This engine delivers
11 MW more power but in the same footprint as the RB211-GT61, and
with an improved efficiency of up to 41.5%-the best in the 35 MW to
45 MW range, Rolls Royce claims. Courtesy: Rolls Royce
8
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POWER | August 2010
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POWER August 2010

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