Environmental Engineering Reference
In-Depth Information
However, the energy collected from the wind turbine is also dependent on
the size of the swept area. herefore, the engineering challenge is to man-
ufacture increasingly light yet resilient rotor blades to permit the manu-
facture of longer rotor blades, thereby increasing the swept area without
proportionately increasing rotational friction.
Over the past 25 years, signiicant progress has been made in regard to
increasing the swept area of wind power systems. As Figure 2.1 illustrates,
in 1985 a typical 500 kW wind power turbines had a rotor diameter of about
15 m. In 2008, it was envisaged that sometime in the near future, a 8-10
MW wind system would become a reality. hat day has arrived. As of June
2013, Vestas's largest wind power system—the V164-8.0 MW wind tur-
bine—boasts a rotor diameter of 164 m, approximately twice the length of
a 747. Its swept area is the size of three football pitches.
In order to expand the swept area of a wind system, the turbines must
be mounted on enormous towers. For example, the Vestas V164-8.0 MW
wind turbine described in the previous paragraph can sit on a tubular steel
tower that is as high as 190 m, approximately the same height as Seattle's
space needle and twice the height of the clock tower which houses Big Ben in
London. One of the added advantages of mounting wind turbines on higher
towers is that airlow at higher altitudes is less turbulent. Whereas many of
the earlier wind power systems were mounted on trellis-like towers, almost
all modern utility-scale wind power systems are mounted on tubular steel
or concrete towers.
he component parts that are found in the nacelle—the gearbox, the
generator, and the yaw motor—play vital roles in optimizing the capture of
wind power. he rotor of a wind turbine is mounted on a main drive shaft
164 m ø
126 m ø
?
112 m ø
Airbus A380
wing span
80m
15 m ø
'85
.05
'87 '89
'91 '93
'95
'97
'99
'01
'03 05
'13
1st year of operation
installed power
.3
.5
1.3
1.6
2
4.5
5
8 MW
Figure 2.1
. he Progressively Improving State Of Wind Turbine Technology
Source
: DONG Energy (2008)
Final Report on Ofshore Wind Technology
. Fredericia, Denmark: Risø National
Sustainable Energy Laboratory, New Energy Externalities Developments for Sustainability Consortium.
