POWER July 2011 - 8

Pushing the 60% Efficiency Gas
Turbine Barrier
Gas turbine makers GE, Siemens, and Mitsubishi Heavy Industries
(MHI) in the last week of May separately profiled unprecedented
results from development or testing of three innovative combined-cycle
gas turbine (CCGT) technologies.
GE Launches Flexible, Efficient CCGT
GE launched its FlexEfficiency 50 Combined Cycle Power Plant-
what it called " a first-of-its-kind " power plant engineered to
deliver an " unprecedented combination of flexibility and efficiency. "
The 510-MW power plant is said to be capable of offering
a fuel efficiency of greater than 61% while featuring a
one-button start in under 30 minutes.
GE said at the launch of the turbine in Paris that the plant
was designed to cost-effectively integrate renewables into power
grids on a large scale. According to the Financial Times, the
plant's 50-Hz gas turbine will initially be manufactured in France
and be targeted at the European Union, which has set a goal that
renewable power should provide 20% of all energy by 2020. GE
has announced no plans for a 60-Hz U.S. model at present.
The new CCGT, which cost more than $500 million in research
and development, draws from the company's jet engine expertise
" to engineer a plant that will ramp up at a rate of more than 50
megawatts per minute, twice the rate of today's industry benchmarks, "
GE said.
Development of the turbine began in 2004 after studies about
how to best integrate intermittent renewable technologies into
the grid showed that power systems of the future would characteristically
see " more variability and uncertainty in the net
load. " These systems could be managed with favorable " policies,
power market structures, operating strategies, and investment
incentives " -and advanced gas turbine technologies with flexible
attributes would play a key role, GE said.
The company said GE engineers were able to avoid the " typical
tradeoffs between flexibility and efficiency by approaching
the plant design from a total equipment and control systems
perspective. " Essentially, the FlexEfficiency 50 integrates a next1.
Model of efficiency. GE launched its FlexEfficiency 50 Combined
Cycle Power Plant in May-a 510-MW power plant capable of
offering a fuel efficiency of 61% and more. Courtesy: GE
generation 9FB gas turbine that operates at 50 Hz (the power
frequency that is most used in countries around the world); a
109D-14 steam turbine, which runs on steam produced from the
waste heat from by the gas turbine; GE's advanced W28 generator;
a Mark VI integrated control system that links all of the technologies;
and a heat-recovery steam generator (Figure 1).
The gas turbine will now be tested in GE's full-loading $170 million
testing facility in Greenville, S.C., at full capacity in a variety
of real-world power plant conditions, beginning in 2014. Commercial
operation and first achievement of 61% is expected in 2015.
GE already has a couple of buyers. In June, China's Harbin
Electric Co. signed a memorandum of understanding for the purchase
of four 9FB gas turbines before 2013, including two that
incorporate FlexEfficiency technology. And in June, the plant was
selected by MetCap Energy Investments, a Turkish project developer,
for what GE says is the world's first integrated renewables
combined-cycle power plant. That plant, to be located in Karaman,
Turkey, will be rated at 530 MW and is scheduled to enter
commercial service in 2015. (For more on integrating renewables
and fossil fuels, see this issue's cover story.)
Siemens: H-Class Turbine Exceeds Expectations
Just days before GE's launch of its new technology, Siemens announced
that it had achieved what it called a " new world record
in power plant efficiency " with the SGT5-8000H gas turbine at
E.ON's Irsching 4 plant in Bavaria, Germany. The decade-long innovation
program for its new generation H-class gas turbine had
surpassed 578 MW and reached a net efficiency of 60.75%. The
Siemens turbine had been designed for 400 MW in simple-cycle
duty and for 600 MW in combined-cycle duty (Figure 2).
Siemens Energy CEO Michael Suess said in a statement that
with this achievement, Siemens had " left all current records with
regard to output and efficiency far behind, " and " raised the bar
for operating flexibility. " Siemens tested a number of corresponding
load gradients and found that more than 500 MW could be
2. More than expected. A Siemens Energy-built combined-cycle
power plant-Irsching 4, near Ingolstadt, Bavaria, featuring Siemen's Hclass
turbine-has achieved an efficiency of 60.75% and an output of 578
MW. This image shows the SGT5-8000H gas turbine in the foreground,
the SGen5-3000W generator, and the SST5-5000 steam turbine-all of
which are arranged on a single shaft. Courtesy: Siemens Energy
8
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POWER July 2011

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