VIABILITY OF WIND ENERGY FOR POWER GENERATION IN NIGERIA.

(Paper presentation at the Nigerian Institution of Mechanical Engineers ‘ Annual General Meeting & International Conference “Coal City 2012 “ on18th October 2012.)

BY

ENGINEER OMEH SEBASTINE CHINONYE ( MD HYBRID MICRO MACHINES PRODUCTS LIMITED)

WHAT IS WIND ENERGY ALL ABOUT?.Wind energy can be simply defined as the energy possessed by moving air mass.The energy possessed by wind is usually in the form of kinetic energy but when in contact with wind turbine blade is transformed into rotational mechanical energy.The mechanical energy is transmitted via the drive system to the wind turbine generator which performs the final conversion to electrical energy.Thus the technology is simple and robust. The only resource is wind which is clean, abundant, free and renewable.

TYPES OF WIND TURBINEWind turbines are of two types namely: •Vertical axis wind turbine and• Horizontal axis turbine.The classifications as vertical and horizontal axis,simply indicate the orientation of the wind turbine rotor axis.

PRINCIPLE OF OPERATION OF WIND TURBINEThe wind turbine principle of operation is simple. It centers onThe Utilization of the aerodynamics forces that act on the airfoil shaped blades as wind flows around them.

When wind flows around airfoil, some forces result, namely:•LIFT FORCE; This force acts in a direction normal to the flow. It is the component of this force that is used by the wind turbine to drive the generator.•DRAG FORCE; The drag force acts in the same direction as the wind. It is an opposing force.•MOMENT FORCE; the moment force arises due to the point of action of the aerodynamics resultant with reference to the hinge point of the airfoil known as the feathering axis.

If the aerodynamics force acts at a point displaced from the feathering axis in the direction towards the leading edge, nose-up moment results, but if the force acts at a point displaced from the feathering axis in direction towards the trailing edge, nose-down moment results.

Basic Theory: The equation of the lift and drag forces acting on airfoil segment of surface area “A” under wind velocity ‘V ‘can be written as follows:FL = ½ рCLAV2

FD = ½рCDAV2

CL and CD are lift and drag coefficient respectively and р is the air density.

The power possessed by moving air across a disc of area A can be given as:Po = 1/2рv3 A = ½π рV3 r2

Where р = air density; r= radius of the disc; V= air velocityFrom the equation above, we can see that a fast moving wind possess a great amount of energy. However, not all the energy can be extracted by the wind turbine. There is a theoretical maximum known as Betz limit which is equal to 59 percent.In practice it is difficult to achieve up to 45 – 50%. The factor above is called the coefficient of capture Cp. The reduction is practice result from losses such as air foil profile loss, whirlpool loss , blade count loss and losses due to aerodynamics interference and gear box friction etc. The air foil profile loss results from the lift to drag ratio (C l /CD) of the blade airfoil. End loss is due to pressure diffusion at the tip of the blade where some air flow from the lower-camber to the upper-camber exists. This over glow of air due to pressure difference also gives rise to a diversion of the in flowing air thus changing its velocity and direction as it encounters the blade contrary to Betz assumption and results in whirlpool loss. When the number of blades increases, the flow of air through the blades gets more complex giving rise to some kind of departure from the established aerodynamics behaviors of the blade thus the blade count loss. This behavior is as a result of aerodynamics interference of one blade with the other due to excessive solidity of the rotor. The solidity of the rotor is the ratio of the actual blades area to the rotor disc area i.e. solidity S = nA/π r2 where n = number of blades, A = area of blade and r = rotor radius. Blade solidity above 0.1 would manifest significant aerodynamic interference.

PREVAILANCE OF WIND NEEDED FOR POWER GENERATION IN NIGERIA.

Operational wind speed requirement for most wind turbines range from 3m/s to 25m/s but most wind turbine achieve the rated out put power at about15m/s wind.

Nigeria is blessed with good wind that is very suitable for the generation of the much needed electric power.

•The wind is all round the seasons

•We do not usually have hurricane type of wind which is dangerous to wind turbines.

•Wind energy potential is well spread along the length and breadth of the country.

WIND MAP OF NIGERIA: Figure below is the wind map of Nigeria at the height of 80m showing areas with wind energy greater than one hundred watts per square meter. From the report it is seen that about 63.34% of the total land mass of Nigeria have wind energy potential below 100w/m2 while 36.66% of the country’s landmass have wind energy potential of over 100w/m2. The available potential wind energy in the said region amounts to a whooping 41,868.67GW untapped.

History of observatory record:

Wind speed history for some cities in Nigeria as obtained from www.wunderground.com [Weather underground web site], a notable weather/forecast site shows that there is abundant wind for power generation in most part of the country.

History for Lagos, NigeriaSaturday, August 13, 2011

Hourly Observations

Time (WAT) Temp. Heat Index Dew Point Humidity Pressure Visibility Wind Dir Wind Speed Gust Speed Precip Events Conditions12:00 AM 24.0 °C - 23.0 °C 94% 1014 hPa 10.0 km WSW 25.9 km/h / 7.2 m/s - N/A Partly Cloudy

12:30 AM 24.0 °C - 23.0 °C 94% 1014 hPa 10.0 km WSW 22.2 km/h / 6.2 m/s - N/A Partly Cloudy

1:00 AM 24.0 °C - 23.0 °C 94% 1014 hPa 10.0 km West 14.8 km/h / 4.1 m/s - N/A Partly Cloudy

2:00 AM 24.0 °C - 23.0 °C 94% 1014 hPa 10.0 km West 20.4 km/h / 5.7 m/s - N/A Partly Cloudy

2:30 AM 24.0 °C - 23.0 °C 94% 1014 hPa 10.0 km WSW 18.5 km/h / 5.1 m/s - N/A Partly Cloudy

3:00 AM 24.0 °C - 23.0 °C 94% 1013 hPa 10.0 km WSW 22.2 km/h / 6.2 m/s - N/A Partly Cloudy

3:30 AM 24.0 °C - 23.0 °C 94% 1013 hPa 10.0 km West 18.5 km/h / 5.1 m/s - N/A Partly Cloudy

4:00 AM 24.0 °C - 23.0 °C 94% 1013 hPa 10.0 km SSW 14.8 km/h / 4.1 m/s - N/A Partly Cloudy

5:00 AM 23.0 °C - 23.0 °C 100% 1013 hPa 10.0 km SW 16.7 km/h / 4.6 m/s - N/A Scattered Clouds

6:00 AM 23.0 °C - 23.0 °C 100% 1013 hPa 10.0 km West 18.5 km/h / 5.1 m/s - N/A Scattered Clouds

7:00 AM 24.0 °C - 23.0 °C 94% 1013 hPa 10.0 km WSW 22.2 km/h / 6.2 m/s - N/A Mostly Cloudy

7:30 AM 24.0 °C - 23.0 °C 94% 1013 hPa 10.0 km WSW 18.5 km/h / 5.1 m/s - N/A Mostly Cloudy

8:00 AM 25.0 °C - 24.0 °C 94% 1013 hPa 10.0 km WSW 20.4 km/h / 5.7 m/s - N/A Mostly Cloudy

8:30 AM 25.0 °C - 24.0 °C 94% 1014 hPa 10.0 km WSW 22.2 km/h / 6.2 m/s - N/A Mostly Cloudy

9:00 AM 25.0 °C - 24.0 °C 94% 1014 hPa 10.0 km WSW 24.1 km/h / 6.7 m/s - N/A Mostly Cloudy

9:30 AM 25.0 °C - 24.0 °C 94% 1014 hPa 10.0 km West 29.6 km/h / 8.2 m/s - N/A Mostly Cloudy

10:00 AM 26 °C - 24 °C 85% 1015 hPa 10 km West 22.2 km/h / - - Mostly Cloudy

10:00 AM 26.0 °C - 24.0 °C 89% 1014 hPa 10.0 km West 22.2 km/h / 6.2 m/s - N/A Mostly Cloudy

11:00 AM 27.0 °C 29.6 °C 23.0 °C 79% 1014 hPa 10.0 km WSW 29.6 km/h / 8.2 m/s - N/A Mostly Cloudy

11:30 AM 27.0 °C 29.6 °C 23.0 °C 79% 1014 hPa 10.0 km West 24.1 km/h / 6.7 m/s - N/A Mostly Cloudy

12:00 PM 26.0 °C - 23.0 °C 83% 1014 hPa 10.0 km WSW 31.5 km/h / 8.7 m/s - N/A Mostly Cloudy

12:30 PM 26.0 °C - 23.0 °C 83% 1014 hPa 10.0 km WSW37.0 km/h / 10.3 m/s

- N/A Mostly Cloudy

2:00 PM 28.0 °C 31.2 °C 23.0 °C 74% 1013 hPa 10.0 km WSW46.3 km/h / 12.9 m/s

- N/A Mostly Cloudy

2:30 PM 28.0 °C 31.2 °C 23.0 °C 74% 1012 hPa 10.0 km WSW46.3 km/h / 12.9 m/s

- N/A Mostly Cloudy

3:00 PM 29.0 °C 32.7 °C 23.0 °C 70% 1012 hPa 10.0 km West 18.5 km/h / 5.1 m/s - N/A Mostly Cloudy

3:30 PM 29.0 °C 32.7 °C 23.0 °C 70% 1012 hPa 10.0 km West48.2 km/h / 13.4 m/s

- N/A Mostly Cloudy

4:00 PM 27.0 °C 29.6 °C 23.0 °C 79% 1012 hPa 10.0 km West 29.6 km/h / 8.2 m/s - N/A Mostly Cloudy

4:30 PM 27.0 °C 29.6 °C 23.0 °C 79% 1012 hPa 10.0 km WNW37.0 km/h / 10.3 m/s

- N/A Mostly Cloudy

5:00 PM 26.0 °C - 23.0 °C 83% 1012 hPa 10.0 km WNW37.0 km/h / 10.3 m/s

- N/A Partly Cloudy

5:30 PM 26.0 °C - 23.0 °C 83% 1012 hPa 10.0 km West33.3 km/h / 9.3 m/s

- N/A Partly Cloudy

6:00 PM 25.0 °C - 23.0 °C 89% 1012 hPa 10.0 km WSW25.9 km/h / 7.2 m/s

- N/A Partly Cloudy

6:30 PM 25.0 °C - 23.0 °C 89% 1012 hPa 10.0 km West18.5 km/h / 5.1 m/s

- N/A Partly Cloudy

7:00 PM 25 °C - 24 °C 92% 1013 hPa 10 km West 18.5 km/h / - - Mostly Cloudy

7:00 PM 25.0 °C - 24.0 °C 94% 1012 hPa 10.0 km West18.5 km/h / 5.1 m/s

- N/A Partly Cloudy

7:30 PM 25.0 °C - 24.0 °C 94% 1012 hPa 10.0 km WSW22.2 km/h / 6.2 m/s

- N/A Partly Cloudy

8:00 PM 25.0 °C - 24.0 °C 94% 1012 hPa 10.0 km West27.8 km/h / 7.7 m/s

- N/A Mostly Cloudy

8:30 PM 25.0 °C - 24.0 °C 94% 1012 hPa 10.0 km West18.5 km/h / 5.1 m/s

- N/A Mostly Cloudy

9:00 PM 24.0 °C - 23.0 °C 94% 1013 hPa 10.0 km West29.6 km/h / 8.2 m/s

- N/A Mostly Cloudy

9:30 PM 24.0 °C - 23.0 °C 94% 1013 hPa 10.0 km WSW18.5 km/h / 5.1 m/s

- N/A Mostly Cloudy

10:00 PM 24.0 °C - 23.0 °C 94% 1013 hPa 10.0 km West20.4 km/h / 5.7 m/s

- N/A Mostly Cloudy

History for Lagos, NigeriaSaturday, August 13, 2011

Daily Observations

History for Sokoto, Nigeria: Top of Page : Month of December, 2009

- - - - - - - - - - - - - - - - - - -

2009 Temp. (°C) Dew Point (°C) Humidity (%)Sea Level Pressure (hPa) Visibility (km) Wind (km/h)

Gust Speed (km/h)

Precip (cm) Events

December high avg low high avg low high avg low high avg low high avg low high avg high sum

1 33 24 16 8 4 1 23 19 15 1014 1012.25 1009 10.0 6.8 4.0 17 12 - 0.0

2 34 26 17 6 4 1 23 18 9 1013 1012.14 1010 10.0 9.4 8.0 28 10 - 0.0

3 34 27 20 6 4 2 21 15 9 1013 1012.00 1011 10.0 10.0 10.0 18 11 - 0.0

4 34 26 17 7 4 2 23 15 9 1014 1010.50

1004 10.0 8.8 8.0 18 13 - 0.0

5 34 26 19 8 4 2 26 17 10 1013 1012.00

1010 10.0 8.8 8.0 22 13 - 0.0

6 35 30 24 6 4 1 17 12 8 1013 1011.00 1009 10.0 10.0 10.0 28 18 - 0.0

7 33 18 18 3 2 1 21 14 8 1013 1012.00 1011 10.0 9.0 8.0 28 17 - 0.0

8 32 26 26 6 4 2 12 12 11 1013 1012.50 1012 10.0 10.0 10.0 20 18 - 0.0

9 33 26 26 6 5 4 15 13 11 1013 1012.00 1011 8.0 7.5 7.0 18 18 - 0.0

10 26 - 26 5 5 5 16 16 16 1014 1014.00

1014 10.0 10.0 10.0 18 18 - 0.0

11 34 26 26 9 9 9 13 13 13 1013 1011.00 1009 10.0 10.0 10.0 18 16 - 0.0

12 33 33 32 3 2 1 8 8 7 1009 1005.00 1001 12.0 11.0 10.0 22 17 - 0.0

13 34 - 34 9 9 9 12 12 12 1010 1010.00 1010 10.0 10.0 10.0 18 18 - 0.0

15 37 37 30 12 11 10 22 17 12 1009 1008.50 1008 10.0 10.0 10.0 18 12 - 0.0

16 36 - 36 - 0 - 5 5 5 1011 1011.00 1011 10.0 10.0 10.0 9 9 - 0.0

17 38 36 32 12 12 11 20 16 13 1010 1009.50 1009 10.0 10.0 10.0 20 17 - 0.0

18 37 35 35 9 9 9 12 11 10 1010 1009.50 1009 10.0 10.0 10.0 26 21 - 0.0

19 37 34 34 9 8 7 10 10 10 1010 1009.50 1009 10.0 9.0 8.0 18 16 - 0.0

21 37 33 30 9 7 5 12 11 10 1014 1011.67 1010 10.0 10.0 10.0 18 17 - 0.0

22 28 - 28 4 4 4 12 12 12 1014 1014.00 1014 10.0 10.0 10.0 28 28 - 0.0

24 36 - 36 9 9 9 11 11 11 1010 1010.00

1010 10.0 10.0 10.0 15 15 - 0.0

25 28 - 28 6 6 6 16 16 16 1015 1015.00 1015 6.0 6.0 6.0 33 33 - 0.0

26 26 26 22 6 6 6 25 22 18 1015 1014.00 1013 10.0 9.0 8.0 37 30 - 0.0

27 35 16 16 10 6 2 25 19 13 1014 1012.00 1010 10.0 10.0 10.0 17 15 - 0.0

29 19 - 17 4 4 4 28 28 28 1013 1013.00 1013 10.0 10.0 10.0 22 22 - 0.0

30 18 - 17 5 5 5 30 30 30 1013 1013.00 1013 10.0 10.0 10.0 18 18 - 0.0

31 24 - 24 7 7 7 24 24 24 1013 1013.00 1013 8.0 8.0 8.0 15 15 - 0.0

History for Sokoto, Nigeria: Month of December, 2009

2009 Temp. (°C) Dew Point (°C) Humidity (%) Sea Level Pressure (hPa) Visibility (km) Wind (km/h)Gust Speed (km/h)

Precip (cm)

Events

Decemberhigh avg low high avg low high avg low high avg low high avg low high avg high sum

History for Enugu, NigeriaMonth of December, 2009 Month of December, 2009 —

Daily Observations

2009 Temp. (°C) Dew Point (°C) Humidity (%) Sea Level Pressure (hPa) Visibility (km) Wind (km/h)

Gust Speed (km/h)

Precip (cm) Events

December high avg low high avg low high avg low high avg low high avg low high avg high sum

1 34 34 28 19 16 14 46 34 21 1008 1007.50 1007 8.0 7.5 7.0 15 10 - 0.0

2 34 26 19 18 16 14 70 48 19 1011 1008.80

1007 8.0 5.8 4.0 15 12 - 0.0

3 34 31 28 23 19 15 68 41 24 1012 1008.50

1006 15.0 12.8 6.0 28 11 - 0.0

4 33 26 19 22 19 17 83 54 30 1011 1009.67

1008 10.0 7.3 4.0 22 7 - 0.0

5 22 21 19 19 18 17 81 79 75 1011 1011.00 1011 8.0 8.0 8.0 15 8 - 0.0

6 34 26 18 16 15 14 77 42 21 1010 1008.33 1006 10.0 8.7 7.0 15 9 - 0.0

7 33 18 18 17 16 14 83 52 21 1009 1008.50 1008 15.0 11.5 8.0 28 17 - 0.0

8 33 20 12 16 16 15 74 46 26 1011 1010.00 1009 7.0 6.3 7.0 20 7 - 0.0

10 32 26 26 22 21 20 65 56 46 1012 1010.50

1009 6.0 6.0 6.0 9 8 - 0.0

12 33 29 29 25 24 25 71 62 54 1010 1009.50

1009 9.0 7.0 5.0 13 4 - 0.0

13 33 33 33 22 20 18 42 36 31 1009 1008.00

1007 8.0 8.0 8.0 22 18 - 0.0

14 30 - 30 23 23 23 60 60 60 1012 1012.00 1012 15.0 15.0 15.0 15 15 - 0.0

15 35 35 31 21 20 20 44 38 31 1007 1006.50 1006 15.0 13.5 12.0 11 10 - 0.0

16 34 - 34 21 21 21 36 36 36 1009 1009.00 1009 10.0 10.0 10.0 0 0 - 0.0

18 36 34 34 23 22 22 41 39 37 1008 1006.50 1005 12.0 11.0 10.0 15 10 - 0.0

19 36 - 36 22 22 22 37 37 37 1005 1005.00 1005 12.0 12.0 12.0 15 15 - 0.0

21 35 34 34 23 21 19 43 36 29 1010 1009.00 1008 10.0 9.0 8.0 22 7 - 0.0

22 34 - 34 23 23 23 41 41 41 1011 1011.00 1011 10.0 10.0 10.0 7 7 - 0.0

23 35 - 32 23 23 23 50 50 50 1008 1008.00 1008 12.0 12.0 12.0 0 0 - 0.0

25 29 - 29 23 23 23 64 64 64 1013 1013.00 1013 10.0 10.0 10.0 0 0 - 0.0

26 34 30 28 21 14 8 57 30 12 1014 1012.50 1011 10.0 9.3 8.0 11 10 - 0.0

27 35 26 17 12 12 11 64 40 16 1012 1010.33 1008 15.0 10.3 6.0 15 10 - 0.0

28 18 - 18 15 15 15 78 78 78 1011 1011.00 1011 10.0 10.0 10.0 0 0 - 0.0

29 22 22 19 16 16 16 74 67 60 1010 1010.00 1010 10.0 9.0 8.0 0 0 - 0.0

30 17 - 17 13 13 13 69 69 69 1010 1010.00 1010 3.0 3.0 3.0 11 11 - 0.0

31 19 - 18 15 15 15 72 72 72 1011 1011.00 1011 6.0 6.0 6.0 0 0 - 0.0

Month of December, 2009 —

Daily Observations

2009 Temp. (°C) Dew Point (°C) Humidity (%) Sea Level Pressure (hPa) Visibility (km) Wind (km/h)Gust Speed (km/h)

Precip (cm)

Events

Decemberhigh avg low high avg low high avg low high avg low high avg low high avg high sum

History for Enugu, Nigeria

Wind Energy Production Wind energy harnessing is very interesting in that the

area of machine in contact with wind is far less than the area of space within which energy is captured. Unlike solar in which the machine element area to potential energy reference area ratio is unity, that of wind is usually less than 0.1.

The low solidity factor of horizontal axis wind conversion machine is a plus to designers in that increase in the rotor radius geometrically increases the capture area and thus the power capture. A single wind turbine of capacity up to ten mega watt (10MW) can be found in the market today. In fact wind energy is better and more economical when harnessed at large capacities. The secret of large capacity wind turbine is long blade.

The power capture of a horizontal axis wind turbine can be written as Pc = CpR2V3

R = rotor radius, V= wind velocity, Cp

= coefficient of capture which is a constant.

Wind information system analysis carried out with one unit vestas V47 (stall) wind turbine when installed around Ama, near 9th mile would yield a total annual energy of 1221.999 MWh/y and average power of 152.75kw see fig B1 through B6 & table B7. This grade of wind turbine has been designed by us at hybrid research centre and it is awaiting production. The same turbine if installed around independence layout area would yield a total annual energy of 1088.486MWh/y and average power of 136.061kw see fig C1 through C6 and table C7. Our HTB24S model wind turbine is similar to the vest as V47 (stall) and would yield about the same power as the vestas V47 turbine used for the analysis.

HTB24S SpecsRotor diameter =50mRated power = 600KWHub height =65mRated wind speed =14m/soperating wind = 3m/s – 25m/s

Wind Energy Cost

Wind energy is the cheapest of all renewable energy sources. This is so because wind energy can be harnessed at larger scale in comparison to another renewable energy sources. Governments all over the world are making much effort to develop renewable energy in view of its environmental friendliness. With much attention and efforts toward renewable energy of which wind is Chief, will soon make wind energy the cheapest of all known energy source.However, wind energy cost in Nigeria like in other countries where wind turbine is not produced is still high. The reasons are:•Wind energy is cheap only when produced at reasonable capacity.•Low awareness due to inadequate promotion of wind energy.•Importation of wind turbine is usually very expensive due to the fact that transportation is a major challenge to international wind turbine market. Example: wind turbine of capacity 2.5MW would have blade length of 45 to 50 meters. Shipment of such long cargo would involve special container and handling arrangement; movements from factory to port and from port to site need special cart/trailer.

In view of the above coupled with other reasons,we at Hybrid Micro Machines Products ltd decided to embark on wind energy research and development.Today, we have produced five models of horizontal axis wind turbine.

New blades produced at Hybrid factory

At HYBRID ,we have developed the needed technology for large scale wind energy production.

What we need is patronage and encouragement and so we call on Nigerian people and government at all levels to invest in

wind energy development.Thank you.

Contact: 08033219473;08084191892