22 Power Engineering International June 2017 www.PowerEngineeringInt.com
Q: What developments are you seeing in
terms of effciency?
A: GPS: It’s an exciting time because we
have HA class turbines coming online and
changing the way power is delivered around
the world, with examples in the US, Pakistan
and Japan. The team is on a path to reach
65 per cent combined-cycle effciency that
drive both capital and operating expense
productivity for customers.
And it’s happening on more than just
across our HA products. We are investing
signifcantly in performance and fuels
improvements across our portfolio with
breakthroughs in advanced metals, coatings,
fuid dynamics and additive-enabled cooling
technologies, all of which will push higher
operating temperatures and enable future
No matter if it’s a 30 MW trailer-mounted
unit or 1. 6 GW utility block – our sustained
commitment to technology and product
development will continue to advance cost-effective, reliable and sustainable power
around the world.
A: SPS: From the perspective of our steam
business, COP21 and climate targets are
driving even more focus on operational
effciencies and we respond to that need
by developing our USC technology further.
The newest coal plants being built are
using GE’s USC technology that can deliver
an effciency rate of up to 47.5 per cent,
which is signifcantly higher than the global
average of 34 per cent. We have improved
this technology even further and are the frst
to market with advanced ultra-supercritical,
or AUSC, the next phase of evolution in steam
AUSC has higher steam parameters
coupled with effciency rates and can
deliver an additional 1. 6 percentage points
of effciency beyond the best technology in
This will drive steam power facilities towards
the 50 per cent effciency mark. In addition
to improving the environment, AUSC delivers
fnancial benefts of $80 million in additional
value to operators if we use a 1000 MW base
plant in Asia as the base case assumption.
The most effcient USC power plant
currently in operation is RDK8 in Germany and
we are in the process of building new USC
plants across Asia and the MENAT region, for
example in Malaysia and in Turkey. We can see
how customers in many of these fast growing
countries are looking for the latest, most
effcient and most advanced technologies to
meet their growing energy needs.
Q: How has materials’ development
enabled effciency improvements?
A: GPS: Advanced metals, coatings, fuid
dynamics and additive-enabled cooling
technologies are all helping to push effciency
Fundamentally, it’s about advancing how
well we mix air and fuel prior to and during
combustion and make cooling air more
effective – that’s where additive manufacturing
(3D printing) can help.
By improving these subsystems and
components, we can lower emissions and
increase effciency without impacting the
lifespan of the turbine. We don’t just do
additive to be cutting edge, we are doing it
to increase performance and drive better
customer outcomes and returns. One
example of this is the DLN fuel nozzle tip, which
enables better mixing of fuel and air, enabling
5 ppm NOx on F-class cycles. We have over
8000 metal additive components running in
the feld today.
It also helps when bringing new products
to market. We couldn’t have done the HA
validation testing we did – at the speed in
which we did it – without creating prototype
parts with additive manufacturing. Instead
of fabricating something out of two or three
parts, you can print it as one. For things like
cooling holes and other small features, you
can print those as well. So this removes an
entire step out of the manufacturing process.
A: SPS: The prices of new materials – such as
the nickel iron-based alloy mentioned earlier,
enabling better effciencies – have come
down in recent years. Hence, increase in
material cost is lower than the beneft that the
higher effciency brings. Nickel iron-based alloy,
for example, has excellent creep properties at
the right cost. We have now commercialized
advanced ultra-supercritical plants, with cycle
conditions of 330 bar/650°C/670°C, using
Q: What about fexibility?
A: GPS: Flexibility is especially key as more
renewables come in. Renewable power
capacity additions will be twice that of gas
additions in the next decade, however gas
turbine power plants will play a vital role.
They serve as a complement to intermittent
renewable generation, offering such valuable
features as rapid start, output fexibility and
For example, the HA can achieve simple
cycle ramp-up in under 15 minutes and full
combined-cycle ramp-up in about 25 minutes.
Or our LM6000, which meets various dispatch
profles with fve-minute starts and can reach
max power in less than ten minutes.
RDK8 steam turbine