Siemens 2007 Annual Report Download - page 59

Energy 59
Ecofriendly electricity
To provide the world’s growing population with reliable supplies of
electricity while mitigating climate change – this is the challenge
now facing energy utilities worldwide. And Siemens – with tech-
nologies ranging from the most advanced gas turbines to offshore
wind farm systems and low-loss high-voltage direct-current (HVDC)
transmission equipment – is delivering solutions.
It doesn’t seem that a two percent increase in effi -
ciency could have much of an impact on climate
change. But, when achieved by high-performance
turbines and power plants, an improvement of even
this magnitude translates into a huge reduction in
CO2 emissions – as our SGT5-8000H gas turbine,
the latest innovation from Siemens’ Power Genera-
tion Group, clearly demonstrates. The 440-ton pow-
er pack will be tested as a stand-alone unit in Block
4 of the Irsching Power Plant in southern Germany
and then expanded to become a combined cycle
power plant, with an output of 530 MWs and an effi -
ciency rating of 60 percent – two percentage points
above the current world record. And these two
points will make a big difference: They’ll cut CO2
emissions at the plant by 40,000 tons a year – the
amount released by 9,500 mid-range cars driven
20,000 kilometers each.
To build a highly compact turbine that can generate
huge amounts of power, you need decades of expe-
rience in heavy engineering, coupled with the lat-
est manufacturing technology. More than 7,000 in-
dividual components – some tiny, others weighing
tons – have to be assembled with painstaking
precision.
Effi ciency ultimately depends on the turbine blades,
which must be able to withstand extremely high tem -
peratures and extremely high levels of wear and
tear. For the Irsching gas turbine – the largest and
most powerful device of its kind, with a power gen-
eration capacity of 340 MWs – Siemens engineers
developed highly resilient nano coatings that can
withstand temperatures of nearly 1,500°C. The ex-
perts also developed a hydraulic system that reduc-
es the gap between the rotor blades and the hous-
ing by a few millimeters after turbine startup. This
design innovation decreases the amount of com-
bustion gases that fl ow past the blades unused.
We’ve already delivered more than 1,100 large gas
turbines to customers around the world. In addi-
tion, over the past 20 years, we’ve built some 520
fossil fuel combined cycle power plants – facilities
that are setting industry standards for energy effi -
ciency and environmental compatibility.
Emissions from our coal-fi red plants, which have
extremely high effi ciency levels of 47 percent, are
also signifi cantly below those of their conventional
counterparts. In the area of CO2-free coal-fi red pow-
er generation, our Power Generation Group offers
two technologies: post-combustion CO2 capture for
existing power plants and pre-combustion CO2 cap-
ture for new ones. With our innovative entrained-
Answers for the environment.