
Chapter 1 Introduction
1
Chapter 1 Introduction
1.1 Development of wind turbine
Since antiquity, mankind has been using wind energy; it is thus not a new idea. For
centuries, windmills and watermills were the only source of motive power for a number of
mechanical applications, some of which are even still used today. But one of today’s greatest
global challenges is the need for more affordable, reliable, clean, secure and renewable
sources of electricity. Relying solely on coal, oil, natural gas and nuclear fuels to generate
electricity is far from being optimal. Fossil fuels are neither renewable nor clean. Their
extraction, transportation and combustion generate air emissions, acid rain, water pollution,
and, most importantly, CO2 emissions that are causing climate change. Moreover, the
constantly increase of fossil fuel price has shown a negative impact on current world
economy. On the other hand nuclear energy has a major drawback in managing the nuclear
waste disposal.
The sudden increase in the price of oil stimulated a number of substantial Government
funded programs of research, development and demonstration. In the USA this led to the
construction of a series of prototype turbines stating with the 38 m diameter 100 kW Mid-0 in
1975 and culminating in the 97.5 m diameter 2.5 MW Mod-5B in 1987. Similar program
were pursued in the UK, Germany and Sweden. There was considerable uncertainty as to
which architecture might prove most cost effective and several innovative concepts were
investigated at full scale. In Canada, a 4 MW vertical axis Darrieus wind turbine was
constructed and this concept was also investigated in the 34 m diameter Sandia Vertical Axis
Test Facility in the USA. In the UK, an alternative veridical axis design using straight blades
to give an H type rotor was proposed by Dr. Peter Musgrove and a 500 KW prototype
constructed. In 1981 an innovative horizontal axis 3 MW wind turbine was built and tested in
the USA. This used hydraulic transmission and, as an alternative to a yaw drive, the entire
structure was orientated into the wind. The best choice for the number of blades remained
unclear for some while and large turbines were constructed with one, two or three blades [10].
The stimulus for the development of wind energy in 1973 was the price of oil and
concern over limited fossil fuel resources. Now, of course, the main driver for use of wind
turbine to generate electrical power is the very low CO2 emissions and the potential of wind
energy to help limit climate change. Wind energy was identified as having a key role to play
in the supply of renewable energy with an increase in installed wind turbine capacity from 2.5
GW in 1995 to 40 GW by 2010. Since 2001 there was some 12 GW of installed wind turbine
capacity in Europe, 2.5 GW of which was constructed in 2000 compared with only 300 MW
in 1993. The average annual growth rate of the installation of wind turbine in Europe from
1993.9 was approximately 40%. The distribution of wind turbine capacity is interesting with
in 2000, Germany accounting for some 45% of the European total, and Denmark and Spain
each having approximately 18%. There is some 2.5 GW of capacity installed in the USA of