Specifications
28
Some of the disadvantages that were observed from the horizontal axis wind turbine
was the fact that much of the time horizontal axis wind turbines are mounted high up on
poles to be available to higher unimpeded wind speeds. However because of the design
specifications of the project the turbine will need to be closer to the ground and will not
have access to the higher wind speeds if it were elevated. Another disadvantage is that
the horizontal axis wind turbine is most efficient when its‟ axis of rotation is orientated
perpendicular to the incoming wind direction. If the wind direction changes the turbine
will lose efficiency and not capture as much of the wind energy unless it is able to
change its‟ orientation depending on the incoming wind direction.
Figure 18 – HAWT Wind Direction
Permission Pending
From the research it was concluded that a horizontal axis wind turbine would best meet
the design specification criteria for this project. All of the factors were taken into account
and an intelligent decision was made as to why it would be best to implement a
horizontal axis wind turbine.
The largest deciding factor came from the cost after looking at potential parts buying a
horizontal axis wind turbine would save a lot more money and since the design did not
call out that the environment that this generator was to be used in would need to
facilitate a vertical axis generator it was decided that the extra expense in a vertical
design was not needed.
The next big factor of choosing what type of turbine to use came from the orientation of
the wind. The vertical axis wind turbine can harness wind coming from any direction but
it was discovered that a horizontal axis wind turbine the size of the one specified in the
design could be easily re-oriented autonomously to adapt to a change in wind direction.
This could be facilitated with the use of pivots and slip rings around the base of the
turbine to allow for rotation and a wind foil located on the aft of the turbine to catch the
changing wind direction. All of these modifications combined would allow the turbine to
move and rotate with the wind to always allow the horizontal axis wind turbine to be
oriented perpendicular to the wind.
Next it was decided where best to deploy such a generator since the design resources
specified Waseda University in Shinjuku-ku, Japan it was determined what the average
wind resources were in that location of the world and if at a later date other locations