Basic HTML Version
Energy and EnviroFiciency
A
crucial factor affecting the energy yield of a wind turbine, besides
air density and wind speed, is the rotor swept area over which the
wind flows.This swept area, in turn, is determined by the length of the
rotor blades.The industry trend is clearly heading in the direction of
longer and longer rotor blades.The Siemens rotor consisting of three
75 m rotor blades has a diameter of 154 m and covers a surface area
of approximately 18 600 sq m, equal to about two and a half soccer
fields.The Siemens 6 MWwind turbine will generate about 65%more
energy using the 75 m rotor blade compared with the Siemens 3,6
MW bestseller using the earlier blade with a length of 58 m.
Dong Energy ordered a total of 300 6 MW wind turbines featuring
the record rotor measuring 154 m in length.These wind turbines are
to be installed in wind power plants off the British coast between
2014 and 2017.
Transporting the world's longest rotor blade is not only techni-
cally or logistically challenging but also an impressive achievement
for the truck's driver.The vehicle is 85 m long, five metres wide and
four metres high
The world's longest rotor blade was loaded onto a special transport
vehicle in the port of Esbjerg. The Siemens B75 rotor blade weighs
about 25 tons, which is equal to the weight of four bull elephants.
Loading required precision, working with exceptional accuracy and a
good eye from all those involved.The rotor blade was escorted by two
accompanying vehicles on the 320 km route from Esbjerg to Osterild,
travelling at a maximum speed of up to 67 km per hour, even though
the transport vehicle is fairly slow.
Once installed in a wind turbine, the 154 m rotor must withstand
huge air masses. At wind speeds of 10 m per second, it captures the
energy of 200 tons of air every second. Siemens' patented Quantum-
Blade technology assures that the rotor blade is up to 20% lighter
than rotor blades produced with conventional methods.
In the Danish town of Osterild, three of these rotor blades, will
be installed in a 6 MW wind turbine and the new technology will be
tested to determine what benefits and advantages it actually provides.
Enquiries: Keshin Govender. Email keshin.govender@siemens.com.
A
s of August 2012 the
South African
Bureau of Standards (SABS)
laboratory
will be re-introducing petrographic testing
services to the coal and minerals industry.
“The SABS laboratory is well placed to
offer a strategic service to businesses across
the Southern African mining region particu-
larly theWaterberg and Botswana coalfields.
The re-introduction of petrographic services
will stimulate foreign direct investment by
renewing trust in the region’s capability to
offer world-class services to the mining and
mineral testing industry” , comments Hein-
rich Williams, General Manager for Mining
and Minerals at SABS.
Coal petrography is a microscopic tech-
nique used to determine a coal’s rank (degree
of coalification) and type (amount and class
of macerals). Accurate petrographic analysis
is an important tool to evaluate bituminous
coals and coal blends and their ability to
produce blast furnace coke.
The analysis of minerals by optical
mineralogy is critical to understanding the
rock's origin, as well as determining coal
characteristics including coke strength which
inevitably lends itself to prime coal market
end-users. Petrography guarantees the high-
est standard possible for customers seeking
services from a testing and certification re-
quirement relevant across the mining sector.
Internationally, coal is currently the most
widely used primary fuel, accounting for
approximately 36% of the world's electric-
ity production. This situation is likely to
remain until at least 2020. South Africa's
coal reserves are estimated at 53 billion
tones, and with our present production rate
there should be almost 200 years of coal
supply left.
Enquiries: HeinrichWilliams.Tel. 012 428 6328.
A long haul
SABS guarantees quality service on testing of minerals
Electricity+Control
September ‘12
58