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And He it is Who sends the winds asheralds of glad tidings, going beforeHis mercy, and We send down purewater from the sky,
Wind Resource Assessment        Program             Prepared by    Eng. Ashour Abdelsalam Moussa            Supervision by...
SOURCES OF ENERGYCONVENTIONAL / NON-RENEWABLE SOURCES     •OIL     •COAL     •WOOD
The World’s EnergyResources Are Limited!
Renewable Energy SourcesSolar                          Tidal         Wind            Geo                  Bio
All renewable energy(except tidal andgeothermal power),ultimately comes fromthe sun.About to per cent ofthe energy coming ...
Why Renewable Energy?• Main Reasons: -    The growth of Energy Demand     Fast depletion of fossil fuel.    Global environ...
Is Solar Energy efficient to meet our needs ? • In one year Earth receives          TWY of   Solar Radiation.  • Energy Co...
Principal Features of Non-ConventionalEnergy         Renewability of the sources.         Flexibility of technology       ...
Why assess wind resource.The Power in the wind is proportional to Cube of the wind speed (       difference in wind speed ...
. Turbine manufacturers concerns max.   turbulence intensity (    ), max. wind shear   acting on blade area (  ) and max. ...
Without wind resource,no wind project will even be viable.
Site Visits and Evaluations    – Visits should be conducted to all suitable      areas with the main goals of verifying si...
Preliminary Area Identification        based on information such as :            previous wind data,            Topography...
Griggs – Putman Wind IndexThis index is based on the permanenttree deformation caused by wind andis useful for estimating ...
Use vegetation to know wind   direction and intensity
Prevailing Wind DirectionImportant to check direction whensetting up instrument
Information in the resourceassessment will include :-       • Daily average wind speeds       • Monthly average wind speed...
Frequency distribution•The basic tool for estimateenergy production.•It shows the % of time that thewind blowing at certai...
Frequency distribution   +     Power Curve                  Energy ProductionTo assess a site’s wind power production pote...
Wind rose is a usefultool to know thewind blows.It is a valuable toolfor project layoutand micro-siting
Wind Power density (W/m )• It is defined as the wind power available per unit  area swept by the turbine blades.• It is a ...
Wind Power Class TableClass   Resource      Wind Power   Wind speed        Potential     density      m/s                 ...
Turbulence intensity• It is the rapid disturbances in the wind speed and    direction.                    Low <           ...
Standard deviation of wind speed calculation (σ)     •A number that indicates how much wind speed changes     above or bel...
Once this assessment iscompleted, an accuratepicture of wind resource atthe site should be clear
Site Screening Process When analyzing a region for potential wind farm locations, the most practical method is to look fir...
Step – Initial Screening of Wind ResourceThe most important factor in selecting a wind energysite is the wind resource its...
Step – Initial Screening for Land SuitabilityAll land with a “Good” or better wind energyresource may not be suitable for ...
Step – Factors Affecting Site SuitabilityThere are many factors that affect site suitability.These factors, which will imp...
Step    – Site Ranking CriteriaNote that the maximum possible score for each criterionis not the same. The differences ref...
MicrositingMicrositing is used to position one ormore wind turbines within a givenland area to maximize the overallenergy ...
Total power input      P/A=    x xVUsable powerP/A=    x xV x Turbine power P/A=    x xV x       x
The distances between the turbineshave a strong effect on the energyoutput of the wind park.This effect is described by th...
Wind turbines are typically arrangedin rows perpendicular to prevailingwinds.If the wind is consistently from onedirection...
•Avoid area of steep slope    The wind on steep slopes  tends to be turbulent.    The construction costs are  greatly incr...
The bottle-neck effect between two elevations
A ridge perpendicular to prevailing wind        direction create better wind potentialTall Ridges clear of trees or obstac...
Highest elevation within a given areaHigh elevation is good and typically meansincreased wind power
Variation of wind speed with heightThe increase of the wind speed as a function ofaltitude is a known effect. Near the gro...
Wind Speeds can be adjusted to another height using the power law equation :            v =v (z /z )∝ V = the unknown spee...
Logarithmic LawThis law takes into account the surfaceroughness of the surrounding terrain                        Z V     ...
zoZo (Roughness Lengths) is the height above groundlevel where the wind speed is theoretically Zero
Landscape Type                                     Zo (m)Large Cities with tall buildingCities with tall buildingsVillages...
Roughness Classes    and Roughness LengthsIf Roughness Length <=Class =           + Ln (length)/Ln(   )If Roughness Length...
ShelterShelter is defined as the relative decrease inwind speed caused by an obstacle in theterrain. Whether an obstacle p...
Obstacle (a house)   angle to corner : α   distance to corner : R   angle to corner : α   distance to corner : R   height ...
• To avoid turbulence, turbine should be placed at a distance    or more times the height of obstacle or vegetation up win...
How to increase the wind         turbine energy productionTo increase the energy production of a wind farm of a  specific ...
Detailed wind resources                        at ZafaranaRed Belt Northing [m]
WAsP ProgramWAsP (Wind Atlas Analysis and Application Program)
What you need is a way to take thewind climate recorded at themeteorological station, and use it topredict the wind climat...
WAsP = OBS + ROU +ORO
WAsP tools• The following tools are available:   . The OWC Wizard   . The WAsP Map Editor   . The WAsP Turbine Editor
Measurement PlanThe Plan should specify thefollowing:-       Measurement parameters       Equipment type, quality and cost...
Measurement ParametersBasic Parameters     – Wind Speed       •    Wind Speed data are the most important           indica...
Measured        Heights  ParametersWind Speed (m/s)   m,   m,   m Wind Direction         m    (deg.)Temperature (ºC)      ...
Optional Parameters       Solar Radiation   •   measure solar resource for later       solar energy studies.   •   Indicat...
Measured     HeightsParameters    Solar      –   m  Radiation  (W/m ) Barometric    –   m  Pressure   (KPa)    Delta     m...
How the measurement plan is        carried out?   – Good Management    Every one involved should be familiar    with the p...
Quality Assurance Plan• no sensor gives a perfect reading• much good data is lost due to low  batteries or some other mino...
OBSERVATION TIMES• Minimum        yearTwo or more years will produce morereliable results• Useful data:   – At least for  ...
Station InstrumentationBasic Sensors   Wind Speed     Cup anemometer or propeller     anemometers are the sensor types mos...
• Cup Anemometer measures Wind Speed.• Constructed from Aluminum and Stainless    Steel.•   Measuring range      :    m/s....
– Propeller anemometers This instrument consists of a propeller mounted on a horizontal shaft. The propeller anemometer al...
Non Rotational Type– Pressure Tube   • Use for calibration– Hotwire  • Non linear, very sensitive– Laser and acoustic anem...
Ultrasonicpopular for marine usedisplay wind speed and direction
SODAR(Sonic Detection And Ranging)system is a ground basedremote sensing system for themeasurement of vertical profilesof ...
Wind Direction    • A wind vane is used to measure wind        direction.    •   The vane aligning itself into the wind.  ...
Wind vane problem arise more fromconfusion on orientation
Data Loggers    • Data logger (or data recorders) is     connected to the sensors for displaying,     storing and transmit...
Installation of Monitoring Stations             The installation phase can              proceed once the site             ...
Tower Installation• Towers can be erected almost anywhere,    but the task is much easier if the terrain    is flat and fr...
Installation Wind Speed and           Directions Sensors–   Mount the upper level sensors at least      cm    above the to...
SafetyRisks:-     • Falling towers     • Falling from towers     • Falling equipmentThe team member should:-     • Be equi...
Data Storage DevicesThere are two commonly used format for recording and storing data :-  – Ring Memory   In this format, ...
Data Storage Capacity (days)       The storage capacity depend on the averaging interval and the       number of channels....
Data Transfer Equipment Data are typically retrieved and transferred to a computer either manually or remotely:-A- Manual ...
Data Reading Programconnect the Data Storage Unit (DSU) to a PC using DSU Reader
B. Remote Data Transfer Remote transfer requires a telecommunication system to link the data logger to the central compute...
DocumentationThe following topics should be included:-  – Site Description     • Location Name     • Elevation/Latitude/Lo...
Site Equipment List• For all equipment (data logger, sensor and support hardware).• Document the following:-  –   Model  –...
Data Protection and Storage  There is a risk of data loss during the  measurement program.   –   faulty or damaged sensors...
Data ValidationThe goal of data validation is todetect errors.The validation routines can begrouped into two main categori...
General System ChecksTwo simple tests evaluate the collected data     • Data Records       The number of data must equal t...
Measured Parameters ChecksThese tests represent the heart of the dataSample Parameter Validation CriteriaAverage Wind Spee...
Treatment of        missing dataParameter         ValueWind SpeedWind directionAir TemperatureTemp. gradientPressureSolar ...
Data Recovery Data Recovery Rate= (Data Records  Collected/Data Records Possible) x For example:-The total possible number...
Measurement System          Accuracy and ReliabilityA- The measurement of wind speed,    for example,  requires that sever...
Quality of wind data• The wind data must be accurate  –   equipment design and specification  –   calibration of anemomete...
Costs and Labor Requirements for a Wind       Resource Assessment Program   Program costs can be divided into three main  ...
C. Related Expenses  •   Travel  •   Accommodation and meals  •   Remote data transfer  •   Land lease fees  •   Re-calibr...
• The estimated total cost for a single  station operated for two years is  about         .• Travel expenses can be econom...
Staffing RecommendationsThe Wind Resource Program should have :- . Project ManagerTasks :-  • Ensure that human and materi...
. Field Manager  Tasks :-  • Installs and maintains the monitoring     equipments. •   Transfer the data to home office. •...
Please don’t hesitate to contact me for any question         e-mail : ashour_ am@yahoo.com
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Capacity Building in the Field of Wind Energy 6 - 15 December, 2009

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Wind resource assessment.

  1. 1. And He it is Who sends the winds asheralds of glad tidings, going beforeHis mercy, and We send down purewater from the sky,
  2. 2. Wind Resource Assessment Program Prepared by Eng. Ashour Abdelsalam Moussa Supervision by Eng. Usama Said Said Wind Energy Dep.,New & Renewable Energy Authority (NREA)
  3. 3. SOURCES OF ENERGYCONVENTIONAL / NON-RENEWABLE SOURCES •OIL •COAL •WOOD
  4. 4. The World’s EnergyResources Are Limited!
  5. 5. Renewable Energy SourcesSolar Tidal Wind Geo Bio
  6. 6. All renewable energy(except tidal andgeothermal power),ultimately comes fromthe sun.About to per cent ofthe energy coming fromthe sun is converted intowind energy. That isabout to timesmore than the energyconverted into biomassby all plants on earth.
  7. 7. Why Renewable Energy?• Main Reasons: - The growth of Energy Demand Fast depletion of fossil fuel. Global environmental problems.
  8. 8. Is Solar Energy efficient to meet our needs ? • In one year Earth receives TWY of Solar Radiation. • Energy Consumption today = TWY.The Answer for the previous question: Yes Solar Energy can meet our needs.
  9. 9. Principal Features of Non-ConventionalEnergy Renewability of the sources. Flexibility of technology adaption. Diversity of the Sources.
  10. 10. Why assess wind resource.The Power in the wind is proportional to Cube of the wind speed ( difference in wind speed makes about change in wind power). This is the primary reason for wind resource assessment.. Wind speed, wind shear*, turbulence** and gust intensity all need to be specified when procuring a wind turbine and designing its foundation….etc.*Wind shears (large differences in the mean wind speed over the rotor) givelarge fluctuating loads and consequently fatigue on the wind turbine blades,because the blades move through areas of varying wind speed.**Turbulence causes dynamic loads on wind turbines. The strength of theturbulence varies from place to place. Over land the turbulence is more intensethan over the sea
  11. 11. . Turbine manufacturers concerns max. turbulence intensity ( ), max. wind shear acting on blade area ( ) and max. one second gust used for foundation designWind Resources assessments are thecornerstone of identifying and mitigating risksand for realizing the potential rewards from aproject.
  12. 12. Without wind resource,no wind project will even be viable.
  13. 13. Site Visits and Evaluations – Visits should be conducted to all suitable areas with the main goals of verifying site conditions.The evaluator should use the following:- • The site topographical map • A Global Positioning System (GPS) • A Camera • A compass
  14. 14. Preliminary Area Identification based on information such as : previous wind data, Topography, Flagged trees ..etc.A new wind measurement sites can be selected.
  15. 15. Griggs – Putman Wind IndexThis index is based on the permanenttree deformation caused by wind andis useful for estimating the averagewind speed in an area.
  16. 16. Use vegetation to know wind direction and intensity
  17. 17. Prevailing Wind DirectionImportant to check direction whensetting up instrument
  18. 18. Information in the resourceassessment will include :- • Daily average wind speeds • Monthly average wind speeds • Annual Average wind speeds • Frequency distribution • Wind Rose • Wind power density • Turbulence intensity
  19. 19. Frequency distribution•The basic tool for estimateenergy production.•It shows the % of time that thewind blowing at certain speed.The wind speed are binned,meaning that speed betweenand m/s are binned as m/s,wind speeds between andm/s are binned as m/s, andso on.
  20. 20. Frequency distribution + Power Curve Energy ProductionTo assess a site’s wind power production potential, thewind speed frequency distribution must be multipliedby a representative wind turbine power curve.
  21. 21. Wind rose is a usefultool to know thewind blows.It is a valuable toolfor project layoutand micro-siting
  22. 22. Wind Power density (W/m )• It is defined as the wind power available per unit area swept by the turbine blades.• It is a true indication of wind energy potential in the site than wind speed alone.• Its value combines wind speed distribution and air density.
  23. 23. Wind Power Class TableClass Resource Wind Power Wind speed Potential density m/s w/m Poor < < Marginal – – Moderate – – Good – – Very Good – – Excellent – – Outstanding > >
  24. 24. Turbulence intensity• It is the rapid disturbances in the wind speed and direction. Low < Medium ~ Large >• High turbulence level cause extreme loading on wind turbine components.• Turbulent locations will severely limit the lifetime of Wind turbines and maximum the chance of their catastrophic failures.• Standard deviation used for turbulence Turbulence intensity = standard deviation of wind speed/ mean wind speed
  25. 25. Standard deviation of wind speed calculation (σ) •A number that indicates how much wind speed changes above or below the mean •Example :For set of data v = m/s n = times v = m/s n = times v = m/s n = timesTotal Number of times occurrence (n) =mean wind speed = (n xv + n xv + n xv )/n =( x + x + x )/ = m/sσ = /(n- ){(n xv ^ + n xv ^ + n xv ^ ) – /n (n xv+n xv +n xv )^ } = {( x( ) + x( ) + ( ) –( )( x + x + x ) } = m /sσ= m/sTurbulence intensity = standard deviation of wind speed/ meanwind speed = / =
  26. 26. Once this assessment iscompleted, an accuratepicture of wind resource atthe site should be clear
  27. 27. Site Screening Process When analyzing a region for potential wind farm locations, the most practical method is to look first for locations that are completely constrained from wind farm development and to remove them from analysis.Some -step process that addresses wind resourceevaluation, evaluation of land suitability, analysisof site-specific suitability, preliminary site ranking.
  28. 28. Step – Initial Screening of Wind ResourceThe most important factor in selecting a wind energysite is the wind resource itself. Many factors can beconsidered in the wind resource assessment process,including: • Local meteorological data • Local “common knowledge” • Biological and physical indicators.
  29. 29. Step – Initial Screening for Land SuitabilityAll land with a “Good” or better wind energyresource may not be suitable for wind energydevelopment Factors that would eliminate a sitefrom consideration include: • National parks, wetlands, or other areas where development is prohibited. • Migration routes of migratory bird species • Some military areas • Culturally sensitive areas (religious, historic, or archeological sites)
  30. 30. Step – Factors Affecting Site SuitabilityThere are many factors that affect site suitability.These factors, which will impact the costs andperformance of a project :- Transmission Capacity and Accessibility Site Terrain, Accessibility, and Complexity Terrain Orientation to Prevailing Wind On-Site Vegetation Soil Conditions Aviation/Telecommunications Conflicts Site Capacity Cost of Land
  31. 31. Step – Site Ranking CriteriaNote that the maximum possible score for each criterionis not the same. The differences reflect the relativeimportance of the criteria.
  32. 32. MicrositingMicrositing is used to position one ormore wind turbines within a givenland area to maximize the overallenergy output of the wind plant.One km of the windy land canhost MW of potential installedcapacity.
  33. 33. Total power input P/A= x xVUsable powerP/A= x xV x Turbine power P/A= x xV x x
  34. 34. The distances between the turbineshave a strong effect on the energyoutput of the wind park.This effect is described by the parkefficiency the relation between :-(the output of the park) / (the outputof the same number of stand-aloneturbines)
  35. 35. Wind turbines are typically arrangedin rows perpendicular to prevailingwinds.If the wind is consistently from onedirection then within-row spacing isless and row-to-row spacing isgreater.Within rows the spacing can varyfrom to times the rotordiameter.Row-to-row distances typically varyfrom to times the rotordiameter.For sites that have energetic winds Typical array lossesfrom multiple directions, the row-to-row spacing and within row spacing for a wind farm areare similar. ~ %.
  36. 36. •Avoid area of steep slope The wind on steep slopes tends to be turbulent. The construction costs are greatly increased.•On hill tops, set the turbinesback from edge to avoid impactsof the vertical component of thewind.
  37. 37. The bottle-neck effect between two elevations
  38. 38. A ridge perpendicular to prevailing wind direction create better wind potentialTall Ridges clear of trees or obstacles in windy partsridgelines that are perpendicular to the prevailingwind direction are preferred to ridgelines that areparallel to the prevailing wind direction.
  39. 39. Highest elevation within a given areaHigh elevation is good and typically meansincreased wind power
  40. 40. Variation of wind speed with heightThe increase of the wind speed as a function ofaltitude is a known effect. Near the ground , thewind speed is reduced due to friction caused byobstacles. the relative increase of wind speed differsfrom one location to another
  41. 41. Wind Speeds can be adjusted to another height using the power law equation : v =v (z /z )∝ V = the unknown speed at height Z v = the known wind speed at the measurement height z ∝ = the wind shear factor. it changes with different roughness, often assumed over flat open terrain but can increase to for area with forest or taller buildings.
  42. 42. Logarithmic LawThis law takes into account the surfaceroughness of the surrounding terrain Z V ln Zo V Z ln Zo Zo (Roughness Lengths)
  43. 43. zoZo (Roughness Lengths) is the height above groundlevel where the wind speed is theoretically Zero
  44. 44. Landscape Type Zo (m)Large Cities with tall buildingCities with tall buildingsVillages, small towns, agricultural land withmany or tall sheltering, forests and very rough.Agricultural land with many houses and plants,or metre tall sheltering with a distance ofapprox. metresAgricultural land with some houses and tallsheltering with a distance of approx. m.Agricultural land with some houses and tallsheltering with a distance of approx. m.Open agricultural area without fencesCompletely open terrain with smooth surfaceWater surface
  45. 45. Roughness Classes and Roughness LengthsIf Roughness Length <=Class = + Ln (length)/Ln( )If Roughness Length >Class= +Ln(length)/Ln( )
  46. 46. ShelterShelter is defined as the relative decrease inwind speed caused by an obstacle in theterrain. Whether an obstacle providesshelter at the specific site depends upon:– the distance from the obstacle to the site (x)– the height of the obstacle (h)– the height of the point of interest at the site (H)– the length of the obstacle (L)– the porosity of the obstacle (P)
  47. 47. Obstacle (a house) angle to corner : α distance to corner : R angle to corner : α distance to corner : R height m, depth : m, porosity :
  48. 48. • To avoid turbulence, turbine should be placed at a distance or more times the height of obstacle or vegetation up wind of the project.
  49. 49. How to increase the wind turbine energy productionTo increase the energy production of a wind farm of a specific design, there are two possibilities available: . Position the wind turbine at a greater height above ground. This option involves a wind turbine price increase. It is therefore necessary to study whether the increased energy production compensates the extra price. . Optimise the wind farm design by re-locating turbines or removing the ones that produce less.
  50. 50. Detailed wind resources at ZafaranaRed Belt Northing [m]
  51. 51. WAsP ProgramWAsP (Wind Atlas Analysis and Application Program)
  52. 52. What you need is a way to take thewind climate recorded at themeteorological station, and use it topredict the wind climate at the turbinesite. That is what WAsP does.
  53. 53. WAsP = OBS + ROU +ORO
  54. 54. WAsP tools• The following tools are available: . The OWC Wizard . The WAsP Map Editor . The WAsP Turbine Editor
  55. 55. Measurement PlanThe Plan should specify thefollowing:- Measurement parameters Equipment type, quality and cost Number and location of met. stations Sensor measurement heights Minimum measurement accuracy, duration and data recovery. Data sampling and recording intervals Data Storage format Data handling and processing procedures Quality control measures Format of data reports
  56. 56. Measurement ParametersBasic Parameters – Wind Speed • Wind Speed data are the most important indicator of a site’s wind energy resource. • Many level measurement heights are encouraged for determining a site’s wind shear characteristics. – Wind Direction • To define the prevailing wind direction • Optimizing the layout of wind turbines within a wind farm. – Temperature • An important descriptor of a wind farm’s operating environment. • Used to calculate air density.
  57. 57. Measured Heights ParametersWind Speed (m/s) m, m, m Wind Direction m (deg.)Temperature (ºC) m
  58. 58. Optional Parameters Solar Radiation • measure solar resource for later solar energy studies. • Indicator of atmospheric stability. Barometric Pressure • Used to calculate air density. Change in Temperature With Height • Provide information about turbulence and used to indicate atmospheric stability.
  59. 59. Measured HeightsParameters Solar – m Radiation (W/m ) Barometric – m Pressure (KPa) Delta m, m, mTemperature
  60. 60. How the measurement plan is carried out? – Good Management Every one involved should be familiar with the program’s overall objectives, measurement plan and schedule. – Qualified Staff The project team should include at least one person with field measurement experience, data analysis and computer skills. – Adequate resources an investment in quality equipment, tools and spare parts.
  61. 61. Quality Assurance Plan• no sensor gives a perfect reading• much good data is lost due to low batteries or some other minor problems. Goals of quality Assurance is to :- – Guarantee the successful collection of high quality data. – Minimize the uncertainties
  62. 62. OBSERVATION TIMES• Minimum yearTwo or more years will produce morereliable results• Useful data: – At least for of the duration of the programme• Omissions: – Data gaps Less than one week
  63. 63. Station InstrumentationBasic Sensors Wind Speed Cup anemometer or propeller anemometers are the sensor types most commonly used for measurement. In practice, the cup type is most commonly used for resource assessment. • Cup anemometer This instrument consists of three cups centrally connected to a vertical shaft for rotation. the aerodynamic shape of the cups converts wind pressure force to rotational torque. A transducer in the anemometer converts this rotational movement into an electrical signal. which is sent through a wire to a data logger.
  64. 64. • Cup Anemometer measures Wind Speed.• Constructed from Aluminum and Stainless Steel.• Measuring range : m/s.• Linearity (High correlation between the output of a sensor and the changes in environment).• Calibration equation U = Ao + Bo x f. (Ao, Bo Calibration Coefficients , f Frequency in Hz).
  65. 65. – Propeller anemometers This instrument consists of a propeller mounted on a horizontal shaft. The propeller anemometer also generates an electrical signal which is sent through a wire to a data logger.
  66. 66. Non Rotational Type– Pressure Tube • Use for calibration– Hotwire • Non linear, very sensitive– Laser and acoustic anemometers • D, Expensive ( Euro)
  67. 67. Ultrasonicpopular for marine usedisplay wind speed and direction
  68. 68. SODAR(Sonic Detection And Ranging)system is a ground basedremote sensing system for themeasurement of vertical profilesof the horizontal wind vectorand turbulence. • Use acoustic signal bounced from ground unit up into the air and reflected back and captured to measure wind speed and direction. • Cost US$ • Excellent for detail studies of winds - m high
  69. 69. Wind Direction • A wind vane is used to measure wind direction. • The vane aligning itself into the wind. • Most wind vanes use a potentiometer type transducer that outputs an electrical signal relative to the position of the vane. this signal is transmitted via wire to a data logger. • The most familiar type uses a fin connected to a vertical shaft.
  70. 70. Wind vane problem arise more fromconfusion on orientation
  71. 71. Data Loggers • Data logger (or data recorders) is connected to the sensors for displaying, storing and transmitting the data in engineering units.
  72. 72. Installation of Monitoring Stations The installation phase can proceed once the site selection has been completed and the necessary equipment acquired. The quality of the data collected depend on the quality of the installation.
  73. 73. Tower Installation• Towers can be erected almost anywhere, but the task is much easier if the terrain is flat and free of trees.• The Guy anchors should be located at each of the four directions (N, E, S, W).• The tower raise along one of these directions, near to the prevailing wind direction as possible.
  74. 74. Installation Wind Speed and Directions Sensors– Mount the upper level sensors at least cm above the tower top to minimize tower shading effects.– In lattice tower position the sensor at least tower widths (one face for triangular lower)– In tubular tower position sensors at least tower diameter.– Orient sensors into the prevailing wind direction.– Locate sensors above the horizontal mounting hardware at a height equal to at least eight diameters of the mounting hardware.
  75. 75. SafetyRisks:- • Falling towers • Falling from towers • Falling equipmentThe team member should:- • Be equipped with the proper safety equipment (hard hats, protective gloves, safety belts and proper foot attire) . • have first aid kit. • Use common sense during the installation (very high wind speed, lightning activity) postpone work until the danger has passed.
  76. 76. Data Storage DevicesThere are two commonly used format for recording and storing data :- – Ring Memory In this format, data archiving is continuous, However, once the available memory is filled to capacity, the newest data record is written over the oldest. the data must be retrieved before the memory capacity of the storage is reached.(DSU X, DSU F) – Fill and Stop Memory Once the memory is filled to capacity, no additional data are archived. the device must be replaced or downloaded and erased before the data logger can archive new data.(DSU , DSU E).
  77. 77. Data Storage Capacity (days) The storage capacity depend on the averaging interval and the number of channels.Int.min Number of Channels
  78. 78. Data Transfer Equipment Data are typically retrieved and transferred to a computer either manually or remotely:-A- Manual Data Transfer This method requires site visits to transfer data. Typically this involves two steps: • Remove and replace the current storage device or transfer data directly to a laptop computer. • Upload the data to a central computer.
  79. 79. Data Reading Programconnect the Data Storage Unit (DSU) to a PC using DSU Reader
  80. 80. B. Remote Data Transfer Remote transfer requires a telecommunication system to link the data logger to the central computer.The communications system may :- – direct wire cabling. – Satellite modems – Phone lines – Cellular phone equipments (more expensive)
  81. 81. DocumentationThe following topics should be included:- – Site Description • Location Name • Elevation/Latitude/Longitude of the site • The installation date and the commission time. • surrounding description • prevailing wind direction • Magnetic Declination
  82. 82. Site Equipment List• For all equipment (data logger, sensor and support hardware).• Document the following:- – Model – Serial Number – the mounting heights – directional orientation
  83. 83. Data Protection and Storage There is a risk of data loss during the measurement program. – faulty or damaged sensors – loose wire connections – temperature extremes – Low battery – data logger malfunctions – Damage hard drives and floppy disks. – Data can be over-written or erased.To reduce the risk of data loss – maintain multi copies of the database, or store each copy in a separate location not in the same building. – Ensure that all personnel (data handling) are fully trained. – Data validation
  84. 84. Data ValidationThe goal of data validation is todetect errors.The validation routines can begrouped into two main categories :- • General System checks • measured parameters checks.
  85. 85. General System ChecksTwo simple tests evaluate the collected data • Data Records The number of data must equal the expected number of measured parameters. A year of ten minute data is records ( x x = ). • Time Sequence This test should should focus on the time and date stamp of each data record.
  86. 86. Measured Parameters ChecksThese tests represent the heart of the dataSample Parameter Validation CriteriaAverage Wind Speed: offset < Avg. < m/sWind Direction : ° < Avg. ≤ °Temperature Seasonal Variability: °C < Avg. < °CBarometric Pressure Average: kPa < Avg. < kPaOne Hour change in wind speed average: < m/sOne Hour change Temperature average: <= ºThree Hour change in Pressure average: < kpa
  87. 87. Treatment of missing dataParameter ValueWind SpeedWind directionAir TemperatureTemp. gradientPressureSolar radiation
  88. 88. Data Recovery Data Recovery Rate= (Data Records Collected/Data Records Possible) x For example:-The total possible number of -minuterecords in January is ( x x ).If records were deemed invalid.The data records collected = -=Data Recovery Rate =( )x =
  89. 89. Measurement System Accuracy and ReliabilityA- The measurement of wind speed, for example, requires that several components (sensor, cabling and data logger), each contributing an error to the measured parameter.Accuracy = {(measured value – Accepted Standard Value) / Accepted Standard Value} X for wind speed ≤ %B- Reliability System reliability is a system’s ability to provide valid data for a parameter over its measurement range. the best indication of a product’s reliability is its performance history.
  90. 90. Quality of wind data• The wind data must be accurate – equipment design and specification – calibration of anemometers – careful mounting of sensors on mast – verification of sensor output (QA)• The wind data must be representative – data collection > year – data recovery > – careful siting of mast• The wind data must be reliable – Operation and maintenance
  91. 91. Costs and Labor Requirements for a Wind Resource Assessment Program Program costs can be divided into three main categories labor, equipment and expensesA. Labor Tasks Administration, Site Selection, Installation, O&M and Data Collection & Handling.B. Equipment Equipment costs can be obtained from manufactures, other items to include in the budget are shipping charges, taxes, insurance, spare parts, tools. The estimated cost for m tubular tower equipped with levels of sensors is about
  92. 92. C. Related Expenses • Travel • Accommodation and meals • Remote data transfer • Land lease fees • Re-calibration of anemometers
  93. 93. • The estimated total cost for a single station operated for two years is about .• Travel expenses can be economized if more than one site is visited.• The total cost to operate a second site is estimated to be to less than the cost for the first site.
  94. 94. Staffing RecommendationsThe Wind Resource Program should have :- . Project ManagerTasks :- • Ensure that human and material resources are available. • Oversee the measurement and quality assurance plans
  95. 95. . Field Manager Tasks :- • Installs and maintains the monitoring equipments. • Transfer the data to home office. • Should be available whenever a problem arises in the site.. Data Manager Tasks:- • Data validation and report generation
  96. 96. Please don’t hesitate to contact me for any question e-mail : ashour_ am@yahoo.com

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