About Wind Power
Wind is air in motion caused by the rotation of the earth and the uneven heating of the atmosphere by the sun.  Air rises as its particles spread out from being heated (making the air less dense and thus lighter.)  Unheated or cool air comes in to take the place of the rising heated air.  This process is calledconvection.   Wind patterns vary according to seasonal, diurnal,and landscape variability and due to changing wind patterns, physical obstacles, in the area, slope, etc.  Wind power machines are classified as mechanical (without electric generators) and electrical.  Mechanical are the ones focused on here, as they are mostly used in rural and remote areas for water pumping.  Electrical windmills connect to a power grid and produce energy converted to electricity for heating, transportation, and other mechanized power.

Photo from "Wind pumping, A Handbook"
by Joop van Meel and Paul Smulders
World Bank Technical Paper #101 ©1989

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Why Wind Power?

• Power demand is growing with increased populations especially in developing countries where fossil fuel supplies are low.
• Wind Power can bring energy to remote areas outside the "electrical grid."  It is cheaper in to start a wind power system than to bring in power lines or other types of fuel which are hard to transport.
• Wind is a renewable resource where as conventional methods such as coal, natural gas, and oil are limited (they have finite lifetimes.)
• Wind Power does not produce the greenhouse (carbon) emissions of conventional energy methods and thus will reduce these if used in their place.
• The price of installation, implementation, and maintenance have dramatically dropped in the past two decades making wind a more viable economic option even in developing countries.  As technology advances, costs will continue to drop.
• Many countries could become energy independent if they used their available wind potential.  For example, China has more wind power potential than it's current consumption.
• Wind power can be converted to other forms of energy (Wind Energy Conversion Systems - WECS):
• Electric - used for heating, light, transport, and running mechanical machines
• Mechanical - mostly converted to hydraulic power to pump a supply of water for irrigation and every day use from deep water levels
• Utilization of wind power for heating and lighting will lesson local environmental degradation as it replaces mass collection of fuel wood (which causes deforestation and  erosion/ watershed damage) as well as the usage of kerosene and animal dung for these purposes.
• Regular diurnal wind patterns in an area suggest that wind power will be an optimum choice for an energy system
• Reliability of WECS is improving with increased technology.

Countries Using Wind Power or Researching in the Wind Power Use:
 *This list is not all inclusive.  These are the findings of my research.
 

Argentina	Canada	Germany	Japan	Netherlands	Sri Lanka	Tobago
Belgium	Cape Verde	Greece	Jordan	Oman	Spain	Trinidad
Botswans	China	India	Kenya	Pakistan	Sudan	Tunisia
Brazil	Denmark	Ireland	Mexico	Portugal	Sweden	UK
Cameroon	France	Italy	Mozambique	Scotland	Tanzania	USA

**The following text and illustrations are adapted from "Wind Pumping : A handbook" by Joop Van Meel and Paul Smulders, World Bank Technical Paper Number 101, Industry and Energy Series. 1989

                                                    1. Wind Pump
                                                    2. Well or Water Source
                                                    3. Suction  and Delivery Lines
                                                    4. Storage Tank
                                                    5. Distribution System
                                                    6. Field Application System (for irrigation)

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                      Ask the questions:

1.How much water is needed?

           This includes daily use plus irrigation for a year round water supply.
           You need to calculate water need accurately as the amount of water necessary for
           the system to pump is directly proportional to the size of the rotor, which in turn is
           directly proportional to the cost.  The rotor and the water storage set up are the major
           components of the cost of the system.
 
 
 

Amount of water  needed to pump==========>>	Size of rotor  necessary================>>	Cost of wind pumping system
		;          ; Water storage

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2.What size system will pump the water necessary?
           To answer this question, we need to calculate the amount of energy needed to pump
           the determined volume of water.  These calculations must allow for loss of energy due
           to converting from one form of energy to another and head loss.  Diameter size of the
           piping in the system can be increased to account for the head loss. Power is the rate the
           energy is used in a given period of time.  You must determine the power needed and
           use this to decide the size of the water pumping device needed to fulfill the demands
           in that period.  NOTE: Calculating the power of your wind supply is complex due to
           the variations in wind and landscape described above.  Attaining an expert in this area
           is more apt to save costs in the long run as precise numbers are important to keep
           system costs down.
 

One important aspect of these calculations is to determine your Critical Month.  This is where your demand of water most exceeds your wind potential.  This the month you should design your pumping system around.  REMEMBER: Rain water may be available to supply some of the water needs during the determined Critical Month and thus your demand of pumped water may not be as high.  Another month may actually have more demand on the wind pump and therefore is your real Critical Month.
 
 

When the Critical Month has an average wind speed of 5 meters/ second (m/s) or higher, then using a windmill is the best option for an energy system.  If the Critical Month has winds of less than 5 m/s, then a hand pumpt might be installed for use during that time or other low wind times.  Wind Power for water pumping is most economical for year round water supplies.

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Photo from "Wind pumping, A Handbook"
by Joop van Meel and Paul Smulders
World Bank Technical Paper #101 ©1989

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Water Storage
Water storage should be utilized for two main purposes:

1. To effeicently use times of higher wind speeds by storing the extra water pumped for later days of less wind.
2. Because wind pumps bring in a irregular modest flow rate all day long while normal use is at high rates for short periods of the day.

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Windmill Components:
From Chapter 2 - Wind Pump Technology, in "Wind Pumping : A handbook" by Joop Van Meel and Paul Smulders.
This chapter goes through the details on how water pumping windmills work.  The basics are explained here.

The Rotor captures the wind's energy and converts it into useful mechanical shaft power.  Recent designs have 4, 6, 8, or 12 blades and operate at higher tip speeds than classical models.  The rotor is fixed to a steel shaft.  Rotors of water pumping windmills range from 1.5 to 8 m in diameter.  In a 4 m/s wind, a rotor of 1.5 diameter may produce up to 24 Watts of mechanical power, and an 8 m diameter windmill up to 680Watts.  In a 5 m/s wind, these values nearly double (46 and 1320 Watts respectively)

A Transmission conveys the energy from the rotor to the pump (rod), sometimes involving intermediate energy conversions.  The pump rod transmits power to the pump.  The efficency of the transmission is somewhere between 70% and 90%. Windmills driving piston pumps (see Handbook for details on other types of windmills) have the most widespread use and therefore are the ones people have the most experience with.  There are two types:

1. Classical windmills typically have a heavy multi-bladed rotor and low speed of operation.  The smaller sizes incorporate a gear box.

2. Modern wind pumps are more varied, including one or more of the following innovations: lighter construction, higher speed of operation, starting helps such as a starting nozzle, balanced pumprod, no gearing, etc.  Therefore modern models have become much more efficient and less costly than older ones.

The Safety System protects the windmill during gusts and storms.  Usually this system is combined with an orientation system.  At low wind speeds the rotor is oriented into the wind; with increasing wind speeds the rotor is gradually turned out of the wind so as to limit the speed of the pump and the forces acting on the structure.  Normally it can be operated manually to stop the windmill.

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Links: Each link has the web address listed next to it as well in case the link fails.

General Info:

• Worldwatch News Brief "Wind Power Sets New Record" - contains useful stats and info including a graph on world wind energy generating capacity, 1980-98 http://www.worldwatch.org/alerts/981229.html

• Sustainable Development International (see different headings for specifics links to pages on this website) http://www.sustdev.org/
• World Wind Generating Capacity Jumps 31 Percent In 2001

http://www.sustdev.org/industry.news/012002/16.02.shtm
• U.S. Dept. of Energy. National Renewable Energy Laboratory;USAID. "Renewable Energy Micro Enterprise"

http://www.dec.org/pdf_docs/PNACK615.pdf
• Veldkamp, Dick.  Recommended Practices for Testing Water-Pumping Windmills Technical Paper #100 of the WorldBank  ©1989http://www-wds.worldbank.org/servlet/WDS_IBank_Servlet?pcont=details&eid=000178830_9810190413461
• Wind pumping, A Handbook  by Joop van Meel and Paul Smulders World Bank Technical Paper #101 ©1989 - This handbook is full of information (much of this website is based upon information gained from this book.)  It includes a chapter on history, technology, wind pump sizing, finances, logistics; and appendices on wind resources, a simple method of caculating costs, blank format sheets for use,

• Windmill World- history and links to great pictures of windmills from around the world  www.windmillworld.com

Projects:

• Projects of the Word Bank

http://www4.worldbank.org/sprojects/
There are three projectsthat come up under a search for "wind energy."
• Mexico:http://www4.worldbank.org/sprojects/Project.asp?pid=P060718
• Sri Lanka:http://www4.worldbank.org/sprojects/Project.asp?pid=P010498
• Argentina:http://www4.worldbank.org/sprojects/Project.asp?pid=P006043
• USAID Project in Panama - http://www.usaid.gov/in/whatsnew/pressreleases/AIDW2000-281.htm

Wind Energy Policy / Wind for Electricity:

• China:  http://ens.lycos.com/ens/nov2000/2000L-11-29-01.html
• Morocco:
• Wind Farms: http://ens.lycos.com/ens/aug2000/2000L-08-04-11.html
• Wind Power Plant: http://www.arabicnews.com/ansub/Daily/Day/981003/1998100319.html
• Patagonia: http://www.businessweek.com/magazine/content/01_13/b3725163.htm
• Mexico:  http://www.mexconnect.com/MEX/lloyds/llydeco9.html#wind_power Feb 2002
• UK: http://www.sustdev.org/industry.news/082001/07.01.shtml http://www.offshorewindfarms.co.uk/ (linked through the above website)
• USA:
• Earth Policy Institute - dedicated to providing a vision of what an environmentally sustainable economy, an eco-economy, looks like, as well as a roadmap of how to get from here to there.  http://www.earth-policy.org/
• Articles on this page:
• Wind Power: The Missing Link in the Bush Energy Plan http://www.earth-policy.org/Alerts/Alert14.htm
• Green Power Purchases Growing by Leaps and Bounds http://www.earth-policy.org/Updates/Update9.htm
• U.S. Farmers Double Cropping Corn and Wind Energy http://www.earth-policy.org/Alerts/Alert3.htm
• Wind Energy Potential in the United States, http://www.nrel.gov/wind/potential.html
• Wind Energy FAQ/ Technical Information,  http://www.awea.org/faq/
• Texas In Big Push To Develop Wind Power http://www.sustdev.org/industry.news/082001/28.01.shtml
• Shell Launches Second Major Investment in U.S. Wind Power Market http://www.sustdev.org/industry.news/012002/30.01.shtml

The Future of Wind Power and Other Renewables:

•  Using windmills under water: “Tidal Currents: A Major New Source of Energy for the Millennium”  http://www.sustdev.org/journals/edition.01/preview/1.107.shtml
• Wind, Tidal/Current, and Wave Energy “Offshore Renewable Energies – Market Developments to 2010”  http://www.sustdev.org/industry.news/032002/26.04.shtml

Problems of Implementation of Renewable Resources and how NGO’s can overcome these barriers:
“Experiences of NGO’s with Renewable Energies in Developing Countries: Some Selected Cases and Lessons Learnt”  http://www.eadi.org/news/RenewableEnergies.pdf

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Articles and Other Resources:

Policy:

• UNEP Press Release, Forecast: Sunny and Windy.  Environment. Vol.44 No.2, March 2002. 7.
• The Solar and Wind Energy Survey Assessment of the United Nations Environment Program will map solar and wind resources in Bangladesh, Brazil, China, Cuba, El Salvedor, Ethiopia, Ghana, Guatemala, Honduras, Kenya, Nepal, Nicaragua, and Sri Lanka.
• Flavin, Christopher.  Bull Market for Wind Energy.World Watch Institute. March/April 1999.
• Global history and statistics
• B. Rajsekhar et al.  Indian wind energy program: performance and future directions.  Energy Policy. Volume 27, 1999. 669-678.

Water Pumping Wind Power Systems

• Ramana Rao, B.V., Rama Krishna, Y.S. and S.C Chowdhary. Wind power potential for irrigation in the arid regions of India. Indian Journal of Power and River Valley Development. September-October 1980. 129-133.
• Ramana Rao, B.V., Rama Krishna, Y.S. and S.C Chowdhary. Performance of Low-Cost Sail-wing Windmill. Agricultural Mechinazation in Asia, Africa, and Latin America.  Winter 1981. 66-68.
• Determines the suitability of windmills for pumping water by estimating the amount of  water that can be pumped at different wind speeds from wells at different depths.  Graphs are created from data for use by others.
• Parikh,M.M and A.K Bhattacharya. Wind Data Analysis for Studying the Feasibility of Windmills for Irrigation. Energy in Agriculture. Vol. 3. Elsevier Science Publishers B.V., Amsterdam - printed in Netherlands. 1984.  129-136.
• Uses probability ten years of mean hourly windspeed data were analyzed to estimate the theoretical discharge of a windmill.  The results  were used together with certain realistic assumptions to estimate the cropping area and the crops that can be irrigated by the estimated discharge of the windmill.

Electrical Windmills

• Singh, D.  Power Generation From Renewable in India: Present Status and Future Prospects. American Solar Energy Society. Conference.  1992.  392-396.
• Twidell, John; Grainger, Bill. Small wind-energy conversion systems (SWECS).  Electronics and Power.  April 1984.  285-289.
• Describes both electrical and mechanical windmills with a focus on electrical.  Advantages and problem areas are outlined.
• Thiringer, Torbjorn; Petru, Tomas and Christer Liljegren. Power Quality Impact of a Sea Located Hybrid Wind Park.  IEEE Transactions on Energy Conversion. Vol. 16, No. 2, June 2001. 123-127
• Power quality problems due to changes in wind speed.  Use of variable speed operation of the turbine by using transistor converters to reduce the power quality impact.
• Gutierrez-Vera, Jorge. Use of Renewable Sources of Energy in Mexico, Case: San Antonio Agua Bendita. IEEE Transactions on Energy Conversion.  Vol. 9, No. 3, September 1994.  442-449.
• A hybrid electric system used in rural Mexico combing solar, wind, and water power.

General Case Studies of Wind Energy:

• Sharma, C.; Chadee, J. A Wind Energy Conversion System (WECS) for the Island of Tobago - A Case Study.Energy Engineering.  Vol. 96, No. 3,  1999.  6+
• M. Yusof Sulaiman et al. Wind Characteristics of Oman.  Energy.  Vol. 27, 2002.  35-46
• S.M. Habali et al.  Wind as an alternate source of energy in Jordan.  Energy Conversion and Management.  Vol. 42, 2001.  339-357.
• Rene Tchinda et al.  Estiamtion of mean wind energy available in far north Cameroon.  Energy Conversion and Management.  Vol. 41, 2000.  1917-1929.
• Menon, P.K.(editor). Bamboo screens to harness more wind power.  Indian Journal of Power and River Valley Development.  Vol. 33, No. 7 & 8, July-August 1983.  221-220.

Critical Month: where the ratio of demand of hydraulic energy to the available wind potential  of that month is largest
diurnal: varying within the course of a single day
head loss: energy loss per unit of weight of the fluid in a tube (or pipe) due to frictional forces within the fluid
Wind Power Potential: simply the amount of wind power available at a site.  Calculations can be found in  Section 1.3 in Wind pumping, A Handbook  by Joop van Meel and Paul Smulders World Bank Technical Paper #101 ©1989. (Potential Wind Speed: wind speed which would be observed in completely flat and open terrain)
Wind Power Machine: prime mover driven by wind power.  It may be used to drive any kind of load: pump, electric generator, etc.

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