Design and Construction of Vertical Axis Wind Turbine
Design and Construction of Vertical Axis Wind Turbine
Design and Construction of Vertical Axis Wind Turbine
Research Article
*Corresponding Author:
Ogunoh Chika C
Email: cezeliora@googlemail.com
Abstract: Increasing demand in energy facilitated the need of clean energy such as wind energy. Residences, buildings
and commercial sites needs more power, but also continuous power. Important facilities such as wireless or radio sets
requires small amount of energy, but with a continuous supply. This project was done to design and construct a vertical
axis wind turbine for small scale use. After an introduction about the historical background of wind turbine, the report
deals with a more accurate analysis of the main type of vertical axis wind turbine, showing their characteristics,
advantages and disadvantages, differences between vertical axis wind turbine and horizontal axis wind turbine and their
operations. The parameter of the wind turbines was discussed and the generators (stator) that can be used to connect the
wind mill to the electricity grid are reported as well. Several statistics are also presented, in order to explain how the
development of the wind energy in Nigeria. Results from trials shows that as the speed increases, there is increase in
voltage and this in turn implies a watt change at different speeds. This also implies that when there is high wind, there is
a higher rpm. The turbine fulfilled all specifications such as efficiency above 80%, 33Watt output power and likewise the
capacity is adequate for its purpose and was proven to be efficient in generation of current.
Keywords: Turbine, wind, electricity, power, energy, fossil fuel and natural gas.
These first windmills were vertical axis wind recognizable for their many blades and typically
turbines. During the middle Ages horizontal axis situated on a farm [1]. Charles Brush, (1888) was one of
windmills were built in Europe and used for mechanical the people who first attempts to generate electricity by
tasks such as pumping water or grinding grain. These using the wind was made in the United States. Among
were the classical four bladed windmills that had a the most important early turbines was the turbine
yawing system and were mounted on a big structure. developed by Marcellus Jacobs. Jacobs’ turbine had
These windmills lost popularity after the industrial three airfoil shaped blades, battery storage and a wind
revolution. At about the same time water pumping wane keeping the turbine facing the wind.
windmills became popular in the United States,
The Eole, a 96 meters tall Darrieus turbine invention). In the United Kingdom the H-rotor was
built in 1986, is the largest VAWT ever constructed investigated by a research team led by Peter Musgrove.
with a rated maximum power of 3.8 MW [6]. The North The biggest H-rotor built in the U.K. was a 500 kW
American Darrieus turbines used in the 80’s mostly had machine, which was designed in 1989 (Mays and
induction generators with gearboxes. However, the Eole Morgan, 1989). This machine had a gearbox and an
had a direct driven generator with a diameter of 12 induction generator inside the top of the tower. One of
meters. It produced 12 GWh of electric energy during the machines had blades that could be folded in high
the five years it was running and reached power levels wind speeds, (see Fig. 4). In the 90’s the German
of up to 2.7 MW. The machine was shut down in 1993 company Heidelberg Motor GmbH worked with
due to failure of the bottom bearing. development of H-rotors and they built several 300 kW
prototypes. These turbines had direct driven generators
The straight-bladed VAWT was also an with large diameters. In some turbines the generator
invention included in the original Darrieus patent [2]. was placed on top of the tower, and in some turbines the
This turbine is usually referred to as the straight-bladed generator was situated on the ground. From this short
Darrieus turbine or the H-rotor, but has also been called historical review it is clear that the first windmill was a
giromill or cycloturbine (different concepts of the same VAWT but that later HAWTs received most attention.
Fig-4: To the left is an H-rotor developed in the U.K. and to the right is one of the Heidelberg rotors
REVIEW OF PROJECT ON VERTICAL AXIS rotation of the motor is directing the current through the
MICRO WIND TURBINE printed wires by a magnetic field of permanent
Murat, 2003 design and construct a project on magnets. The printed motor has guided magnetic fields
Vertical Axis Micro Wind Turbine. This study was so that the power produced is very efficient. Like all
done to investigate the design and development of the DC motors this machine has a commutator to take the
vertical axis micro wind turbines. The contribution of current out through two wires.
counter rotating impellers with a freely rotating
generator to produce energy was investigated. From the These motors can produce about the same
analysis, Solid works, Mathcad and Abacus CAE amount of electricity as motorcycle alternators with
programs were used to design and to analyze the similar rotational speeds, while they have far less inertia
Vertical Axis Micro Wind Turbine. Possible due to small weight. Because of their small dimensions
developments were considered. Heuristic method was and small inertias which are less than motorcycle
used to complete the task of design of a vertical axis alternators and also their highly efficient power output.
micro wind turbine. It was imagined that the task has The Shafts which are the easiest components to
been completed and all the targets were reached. The manufacture and design, so that they were required to
main consideration of the wind turbine was its counter be designed in connection with other components such
rotating blades that reduce the inertia and increase the as impellers, slip rings, frames etc. However, their basic
relative speed of the motor shaft. It must have a frame cross sections need to be chosen. As all the components
to hold the bearings and two identical counter rotating have inner diameter to fit on a shaft, the outer shape of
blade components such as Savonius or Darrieus blade the shaft was chosen as round. Possible round shapes
types, etc. these two blade components are to be for shafts can be suggested as; solid shaft and hollow
connected to two different shafts. Then, the torque shaft.
should be gathered through a generator whose stator is
connected to one of the shafts while the rotor is However, using a hollow shaft limits the
connected to the other shaft. As the two separate shafts possibilities of connections and fits, so that a solid shaft
are connected to the generator, the power has to be which will also have higher inertia but also higher
transmitted by a slip ring to a battery tank, the grid or strength will be used in the final design. In addition,
the experimental measurement devices. In the assembly solid shaft will be machined to create steps as so that
process, there are 7 points of interest to be concerned the bearings will be fitted easily to the ends.
with; degrees of freedom (movement), material
differentiation, product and establishment (replace In this research, it was revealed that using a
ability) considerations, differentiation of functions, counter rotating wind turbine with a freely rotating
particular functional conditions and design generator can produce higher amounts of power than
considerations. All these points are examined during the common wind generators. Even though the power
complete concept design process. The generator used output of counter rotating vertical axis micro wind
for the project was the Printed DC motors which are a turbine was 6 times higher than the total of the two
kind of improved axial flux permanent magnet (AFPM) separate wheels‟ power outputs it has to be due to the
machines. They are also known as Printed Circuit power curve of the generator which indicates that
(PCB) or "Pancake" Motors. Printed DC motors have increasing rotation speeds the output increases
very thin structure because the wires are placed on a drastically in the beginning.
thin disk and the magnets are relatively small, the
RESULT OF THE DESIGNED VERTICAL AXIS small scale use like charging of batteries, lightening of
WIND TURBINE electric bulb etc. The turbine is made up of four parts,
The performance of the machine was namely the stator, hub, magnetic disk and the blade
satisfactory during the preliminary tests. Voltage was (Figure 5).
generated accordingly. The machine can be applied for
DISCUSSION ON THE PERFORMANCE TESTS speed increases, there is increase in voltage and this in
From the graph above, the speed of the turbine turn implies a watt change at different speeds. This also
was gotten by running it with an electric motor and the implies that when there is high wind, there is a higher
rpm was taken and the voltage output was taken with a rpm.
multimeter. From the graph also, we find out that as the