8/25/20152 ” وهو الذى أرسل الرياح بشراً بين يدى رحمته ، وأنزلنا من السماء ماءً طهوراً ” الفرقان - 48 And He it is Who sends the winds as heralds of glad tidings, going before His mercy, and We send down pure water from the sky,

8/25/20153 Wind Resource Assessment Program Prepared by Eng. Ashour Abdelsalam Moussa Wind Energy Dep., New & Renewable Energy Authority (NREA)

8/25/20154 The World’s Energy Resources Are Limited! The World’s Energy Resources Are Limited!

8/25/20155 World Wind Energy 2010 Worldwide capacity reached Megawatt, out of which Megawatt were added in 2010 All wind turbines installed by the end of 2010 worldwide can generate 430 Terawatt hours per annum, more than the total electricity demand of the United Kingdom, the sixth largest economy of the world, and equalling 2,5 % of the global electricity consumption. The wind sector in 2010 had a turnover of 40 billion Euro and employed 670’000 persons worldwide.

8/25/20156 World Market Update 2009March Page 6 China became number one in total installed capacity and the center of the international wind industry, and added Megawatt within one year, accounting for more than 50 % of the world market for new wind turbines. Germany keeps its number one position in Europe with Megawatt, followed by Spain with MW.

8/25/20157 World Market Update 2009March Page 7

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9 Wind

8/25/ Why assess wind resource 1.The Power in the wind is proportional to Cube of the wind speed (10% difference in wind speed makes about 33% change in wind power). This is the primary reason for wind resource assessment. 2.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) give large 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 the turbulence varies from place to place. Over land the turbulence is more intense than over the sea

8/25/ Turbine manufacturers concerns max. turbulence intensity (16%), max. wind shear acting on blade area (0.2) and max. one second gust used for foundation design Wind Resources assessments are the cornerstone of identifying and mitigating risks and for realizing the potential rewards from a project.

8/25/ Without wind resource, Without wind resource, no wind project will even be viable.

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8/25/ This index is based on the permanent tree deformation caused by wind and is useful for estimating the average wind speed in an area. Griggs – Putman Wind Index

8/25/ Use vegetation to know wind direction and intensity ميل خفيف للاغصانميل متوسطميل كامل والساق عمودية على الارض الساق عمودية والاغصان ثابتة االساق عمودية والاغصان متحركة ميل جزئى للساق والاغصان ميل شبه كامل للساق والاغصان الساق والاغصان كالسجادة

8/25/ Prevailing Wind Direction Important to check direction when setting up instrument

8/25/ Information in the resource assessment will include :- Information in the resource assessment will include :- Daily average wind speeds Daily average wind speeds Monthly average wind speeds Monthly average wind speeds Annual Average wind speeds Annual Average wind speeds Frequency distribution Frequency distribution Wind Rose Wind Rose Wind power density Wind power density Turbulence intensity Turbulence intensity

8/25/ The wind speed are binned, meaning that speed between 0 and 1 m/s are binned as 1 m/s, wind speeds between 1 and 2 m/s are binned as 2 m/s, and so on. Frequency distribution The basic tool for estimate energy production. It shows the % of time that the wind blowing at certain speed.

8/25/ Frequency distribution Power Curve Energy Production + To assess a site’s wind power production potential, the wind speed frequency distribution must be multiplied by a representative wind turbine power curve.

8/25/ Wind rose is a useful tool to know the wind blows. It is a valuable tool for project layout and micro-siting

8/25/ Wind Power density (W/m 2 ) It is defined as the wind power available per unit area swept by the turbine blades. 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. 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. Its value combines wind speed distribution and air density.

8/25/ ClassResource Potential Wind Power density w/m2 Wind speed m/s 1Poor < 200 < 5.6 2Marginal 200 – – 6.4 3Moderate 300 – – 7 4Good 400 – – Very Good 500 – – 8 6Excellent 600 – – 8.8 7Outstanding > 800 > 8.8 Wind Power Class Table

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8/25/ It is the rapid disturbances in the wind speed and direction. It is the rapid disturbances in the wind speed and direction. Low < 0.1 Medium 0.1 ~ 0.25 Large > 0.25 High turbulence level cause extreme loading on wind turbine components. 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. Turbulent locations will severely limit the lifetime of Wind turbines and maximum the chance of their catastrophic failures. Standard deviation used for turbulence Standard deviation used for turbulence Turbulence intensity = standard deviation of wind speed/ mean wind speed Turbulence intensity

8/25/ Standard deviation of wind speed calculation (σ) A number that indicates how much wind speed changes above or below the meanA number that indicates how much wind speed changes above or below the mean Example :For set of data v1 =6 m/s n1= 19 times v2 =7m/sn2= 54 times v3=8 m/sn3= 42 times Total Number of times occurrence (n) = 115 mean wind speed = (n1xv1 + n2xv2 + n3xv3)/n = (19x6 +54x7 + 42x8)/ 115 = 7.2 m/s σ 2 =1/(n-1){(n1xv1^2 + n2xv2^2 + n3xv3^2) – 1/n (n1xv1 +n2xv2 +n3xv3)^2} =1/114 {(19x(6) 2 +54x(7) 2 +42(8) 2 – (1/115)(19x6 + 54x7 +42x8) 2 } = m2/s2 σ = m/s Turbulence intensity = standard deviation of wind speed/ mean wind speed = / 7.2 = 0.097

8/25/ Once this assessment is completed, an accurate picture of wind resource at the site should be clear

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8/25/ Site Ranking Criteria Note that the maximum possible score for each criterion is not the same. The differences reflect the relative importance of the criteria.

8/25/ Micrositing Micrositing is used to position one or more wind turbines within a given land area to maximize the overall energy output of the wind plant. One km2 of the windy land can host 5 – 7 MW of potential installed capacity. One km2 of the windy land can host 5 – 7 MW of potential installed capacity. 100 MW wind farm needs (15-20 km2)

8/25/ Total power input P/A= 0.5x  xV 3 Usable power P/A= 0.5x  xV 3 x 16/27 Turbine power P/A= 0.5x  xV 3 x 16/27x 

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8/25/ The distances between the turbines have a strong effect on the energy output of the wind park. This effect is described by the park efficiency the relation between :- (the output of the park) / (the output of the same number of stand-alone turbines)

8/25/ Wind turbines are typically arranged in rows perpendicular to prevailing winds. If the wind is consistently from one direction then within-row spacing is less and row-to-row spacing is greater. Within rows the spacing can vary from 1.5 to 5 times the rotor diameter. Row-to-row distances typically vary from 10 to 20 times the rotor diameter. For sites that have energetic winds from multiple directions, the row-to- row spacing and within row spacing are similar Typical array losses for a wind farm are 2~4 %.

8/25/ Avoid area of steep slopeAvoid area of steep slope  The wind on steep slopes tends to be turbulent.  The construction costs are greatly increased. On hill tops, set the turbines back from edge to avoid impacts of the vertical component of the wind.On hill tops, set the turbines back from edge to avoid impacts of the vertical component of the wind.

8/25/ The bottle-neck effect between two elevations

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8/25/ Highest elevation within a given area High elevation is good and typically means increased wind power

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8/25/ Variation of wind speed with height

8/25/ Wind Speeds can be adjusted to another height using the power law equation : v 2 =v 1 (z 2 /z 1 ) ∝ v 2 =v 1 (z 2 /z 1 ) ∝ V 2 = the unknown speed at height Z2 v 1 = the known wind speed at the measurement height z1 ∝ = the wind shear factor. it changes with different roughness, often assumed 0.14 over flat open terrain but can increase to 0.25 for area with forest or taller buildings.

8/25/ Z o (Roughness Lengths) Logarithmic Law This law takes into account the surface roughness of the surrounding terrain

8/25/ zozozozo Zo (Roughness Lengths) is the height above ground level where the wind speed is theoretically Zero

8/25/ How to increase the wind turbine energy production To increase the energy production of a wind farm of a specific design, there are two possibilities available: 1.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. 2.Optimise the wind farm design by re-locating turbines or removing the ones that produce less.

8/25/ Detailed wind resources at Zafarana

8/25/ Please don’t hesitate to contact me for any question

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