Layout of Wind Projects - Revision history

Lisafeldmann at 11:29, 30 June 2015

2015-06-30T11:29:02Z

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Wiki Gardener at 14:12, 28 December 2014

2014-12-28T14:12:17Z

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Ranisha at 12:36, 29 August 2014

2014-08-29T12:36:35Z

Ranisha at 13:09, 12 August 2014

2014-08-12T13:09:51Z

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Wiki Gardener: Wiki Gardener moved page Layout of wind projects to Layout of Wind Projects without leaving a redirect

2014-06-12T14:00:23Z

Wiki Gardener moved page Layout of wind projects to Layout of Wind Projects without leaving a redirect

Wiki Gardener at 13:59, 12 June 2014

2014-06-12T13:59:55Z

Wiki Gardener at 13:57, 12 June 2014

2014-06-12T13:57:16Z

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Katharina Wiedemann at 13:48, 15 May 2012

2012-05-15T13:48:42Z

Nils Marscheider at 11:50, 28 August 2011

2011-08-28T11:50:15Z

AnkeMaria at 07:40, 8 August 2011

2011-08-08T07:40:51Z

@@ Line 12: / Line 12: @@
 In this map, it can be clearly seen that ridges in the west and and in the east have considerably more favourable wind conditions than the plain in between, caused by the shadowing effects of the ridges and the speed-up effect atop a hill. In this example military installations north of the road (red line) are limiting the wind park area to the region south of the road until it reaches the eastern ridges. The villages around the site (orange areas) are furthermore restricting the available space, as noise emissions from the wind turbines and the shadow flicker caused by the moving turbine rotors cause stress to the inhabitants of these villages if specific values are exceeded.
-[[Layout of Wind Projects#Overview|Go to Top]]
+[[Layout_of_Wind_Projects#toc|►Go to Top]]
 = Wind Turbine Selection<br/> =
@@ Line 36: / Line 36: @@
 If these advanced options are not available, it will be necessary to choose a hub height, which does not exceed the height for qualified wind regime predictions for the specific site characteristics. At the Ashegoda site meaningful prediction of the wind regime was considered possible up to hub heights of 50 to 60 m. Thus the costs related to these hub heights have been considered in the feasibility study for the Ashegoda wind park.
-[[Layout of Wind Projects#Overview|Go to Top]]
+[[Layout_of_Wind_Projects#toc|►Go to Top]]
 === Determination of the Optimal Unit Size ===
@@ Line 107: / Line 107: @@
 <br/>
-The lower total number of V80 / E-70 wind turbines compared to the number of E-48 / V52 turbines is due to the effect that the distances between Multi-Megawatt turbines have to be considerable larger which may cause a reduced total installed capacity and thus a lower total energy production compared
+The lower total number of V80 / E-70 wind turbines compared to the number of E-48 / V52 turbines is due to the effect that the distances between Multi-Megawatt turbines have to be considerable larger which may cause a reduced total installed capacity and thus a lower total energy production compared to a 800 kW / 850 kW wind turbines layout.<br/>
 to a 800 kW / 850 kW wind turbines layout.
 {| border="0" align="left" cellspacing="1" cellpadding="1" style="width: 100%"
 |+ Energy Yields [MWh/wind turbine/y]
@@ Line 125: / Line 124: @@
 | 5,704
 |}
 <br/>
-This calculation is clearly showing the higher specific investment costs of the Multi-Megawatt-turbines compared to the 800 kW turbine class. If there is sufficient space available at the site (which is a limiting factor in most European sites today) to set up the installed capacity with smaller turbines like the 800 kW turbines in the example, a smaller turbine class could be a preferred choice, in case the transportation of large turbines to the site is difficult and connected to additional costs.<br/>
+<br/>This calculation is clearly showing the higher specific investment costs of the Multi-Megawatt-turbines compared to the 800 kW turbine class. If there is sufficient space available at the site (which is a limiting factor in most European sites today) to set up the installed capacity with smaller turbines like the 800 kW turbines in the example, a smaller turbine class could be a preferred choice, in case the transportation of large turbines to the site is difficult and connected to additional costs.<br/>
 Furthermore delivery time could be an important variable: Generally spoken smaller proven wind turbines have shorter delivery time as the large multi-megawatt machines. Thus, developers of a wind project have to conduct a small survey, which provider of wind turbines is able and willing to deliver the turbines to the country the project is located.<br/>
-[[Layout of Wind Projects#Overview|Go to Top]]
+[[Layout_of_Wind_Projects#toc|►Go to Top]]
 === Turbine Distances / Micro-siting<br/> ===
-For the micro-siting certain minimum distances between the individual wind turbines have to be observed. A common rule of thumb specifies three to five rotor diameters in cross wind directions (less than three is possible under some circumstances) and six to eight rotor diameters in main wind direction as a minimum spacing between the individual turbines. The minimum distance of three times or less the rotor diameter in cross wind direction is only feasible in case the wind direction is strictly perpendicular to the row of wind turbines.
+For the micro-siting certain minimum distances between the individual wind turbines have to be observed. A common rule of thumb specifies three to five rotor diameters in cross wind directions (less than three is possible under some circumstances) and six to eight rotor diameters in main wind direction as a minimum spacing between the individual turbines. The minimum distance of three times or less the rotor diameter in cross wind direction is only feasible in case the wind direction is strictly perpendicular to the row of wind turbines. The smallest distances in cross wind direction are determined by a layout development iteration process, carried out under the condition that the wake losses do not fall below a chosen average level for the individual turbines, which is considered as necessary for the economical operation of the wind farm (e.g. the wake losses do not cause decrease in energy output below 85 % for the following wind turbines). Depending on the location of the individual wind turbine and the ambient conditions (topography, location of nearby wind turbines, number of wind turbines towards the main wind direction) the distance between two adjacent turbines can be larger.<br/>
+<br/>For the Ashegoda wind project the minimal distances are summarized in the following table. As the wind turbines at this site should be erected in a single row, the distance of the turbines in the prevailing wind direction is not considered. If space is not a limiting factor for a wind park, the placement in a single row is very benificial because an important part of the wake effects can be avoided.<br/>
 {| border="0" align="left" cellspacing="1" cellpadding="1" style="height: 193px; width: 100%"
@@ Line 175: / Line 172: @@
 In the example layout the orientation of the central part of the eastern ridge nearly parallel to the main wind direction (southeast) prevents the more intensive usage for wind turbines as these will be situated behind each other in the main wind direction while the village at the eastern edge of the wind park area limits the length of the southeasternmost row of turbines. Further wind turbines at the northern end of the row will cause the exceedance of the noise level limits for the village. Similar limitations exist for the northern end of the westernmost row of turbines.<br/>
-[[File:Layout-example for the Ashegoda wind park in Ethiopia.jpg|frame|center|180px|Figure 4: Layout example for the Ashegoda wind park in Ethiopia]]<br/>[[Layout of Wind Projects#Overview|Go to Top]]
+[[File:Layout-example for the Ashegoda wind park in Ethiopia.jpg|frame|center|180px|Figure 4: Layout example for the Ashegoda wind park in Ethiopia]]<br/>[[Layout_of_Wind_Projects#toc|►Go to Top]]
 = Turbulence<br/> =
@@ Line 187: / Line 184: @@
 New studies show that the Frandsen-Model overestimates the turbulence applied to the turbines. The Empirical Turbulence Dutch TNO Laboratory 1993 Model could be chosen as alternatively. A consultation of the manufacturers of the wind turbines for checking the turbulence impact is generally required.<br/>
-[[Layout of Wind Projects#Overview|Go to Top]]
+[[Layout_of_Wind_Projects#toc|►Go to Top]]
 = Noise Impact<br/> =
@@ Line 232: / Line 229: @@
 Considering that identified noise sensitive areas can be assigned to the Village centres with mixed utilisation, the limiting noise standard for the operation of the wind farm in the example of Ashegoda is an impact level of 45 dB (A) at night time.
-[[Layout of Wind Projects#Overview|Go to Top]]
+[[Layout_of_Wind_Projects#toc|►Go to Top]]
 = Shadow Impact =
@@ Line 240: / Line 237: @@
 The estimations are carried out for the worst case that the sun is always shining, 365 days per year. An additional calculation can be performed using the real sunshine probability.
-[[Layout of Wind Projects#Overview|Go to Top]]
+[[Layout_of_Wind_Projects#toc|►Go to Top]]
 = Further Information =
@@ Line 246: / Line 243: @@
 *[[Portal:Wind|Wind Portal on energypedia]]
-[[Layout of Wind Projects#Overview|Go to Top]]
+<br/>
 = References =

@@ Line 1: / Line 1: @@
 = Overview =
 = Wind Potential Map<ref>The contents of this article have been prepared by the project team of the feasibility study of the Ethiopian wind park Ashegoda, conducted by the Deutsche Gesellschaft für internationale Zusammenarbeit (GIZ) in cooperation with the Austrian development agency and Lahmeyer international. Originally the contents have been published as: GTZ (2006) Feasibility Study for Wind Park Development in Ethiopia and Capacity Building - Ashegoda Wind Park Site), retrieved 11.7.2011 [[http://www.gtz.de/de/dokumente/en-feasibility-study-wind-park-ashegoda-2006.pdf]]</ref> =
@@ Line 16: / Line 14: @@
 = Wind Turbine Selection<br/> =
-==== Suitable Tower Heights<br/> ====
+=== Suitable Tower Heights<br/> ===
 Typically, wind speeds are higher with increasing levels above ground. For that reason higher towers can exploit higher wind speeds so that the annual energy production can be increased correspondingly. The counteracting effect is the respective additional investment cost for the tower and the foundation. In some countries available crane capacities could be a further limiting factor.<br/>
@@ Line 22: / Line 20: @@
 The tower heights for wind turbines are chosen to find a good combination of energy yield which is increasing with tower height, and costs for tower and foundation, which are increasing with tower heights. Furthermore for larger turbines, the tower heights are also increasing in general. Especially in lower wind speed areas the tendency towards higher hub heights can be found.<br/>
-The following table will present the costs of several turbines types in connection with different hub heights showing the effect of higher hub heights described above: <br/>
+The following table will present the costs of several turbines types in connection with different hub heights showing the effect of higher hub heights described above:<br/>
 [[File:Cost of turbines related to hub height.jpg|frame|center|180px|Figure 2: Turbine costs in accordance with several hub heights]]This calculation was done with official market prices for the wind turbines of the named manufacturer and the production estimation is connected to the wind conditions at the Ashegoda wind park site. On the x-axis the standard hub height of the selected turbines in meters are plotted, and on the y-axis the specific investment costs in /kWh are presented, calculated by the estimated investment costs devided by the expected annual energy output (P75-value).<br/>
@@ Line 28: / Line 26: @@
 The use of larger hub heights, above 60 m and up to 100m will cause higher costs for towers, foundations and the erection period, as well as higher crane costs.<br/>
-Besides wind speed characteristics the choice of hub height depends on the terrain: For example the Ashegoda wind project site in Ethiopa has a quite wind speed characteristic (characterised as wind class III b according to the IEC regulations) and the terrain at the site can be described as complex. Therefore the extrapolation of the wind speed at higher hub heights compared to the height of the measuring mast is associated with comparatively high uncertainties. These uncertainties could be reduced using higher measuring masts or higher order models for the flow calculations like mesoscalic models like KLIMM. <br/>
+Besides wind speed characteristics the choice of hub height depends on the terrain: For example the Ashegoda wind project site in Ethiopa has a quite wind speed characteristic (characterised as wind class III b according to the IEC regulations) and the terrain at the site can be described as complex. Therefore the extrapolation of the wind speed at higher hub heights compared to the height of the measuring mast is associated with comparatively high uncertainties. These uncertainties could be reduced using higher measuring masts or higher order models for the flow calculations like mesoscalic models like KLIMM.<br/>
 If these advanced options are not available, it will be necessary to choose a hub height, which does not exceed the height for qualified wind regime predictions for the specific site characteristics. At the Ashegoda site meaningful prediction of the wind regime was considered possible up to hub heights of 50 to 60 m. Thus the costs related to these hub heights have been considered in the feasibility study for the Ashegoda wind park.
+<br/>
 === Determination of the Optimal Unit Size ===
 <u>The selection of the wind turbine type is depending on several criteria, such as:</u>
 *Transportation to the foreseen wind park site
 *Available space on site
 *Orographical conditions on site which may prevent the installation of larger turbines in the Megawatt - range
@@ Line 50: / Line 44: @@
 *Turbine types available at the regional market
+<br/>
 Wind turbines in the Multi-Megawatt range require a higher level of maintenance to be performed by the turbine manufacturer - compared to proven turbine types in the range below one Megawatt. In addition, proven in the past, almost all wind turbine manufacturers are not willing to offer turbines in the Megawatt class for countries which are just entering the wind energy market.
@@ Line 58: / Line 52: @@
 *More offers from wind turbine manufacturers will be available in the case a tendering for 800 kW range wind turbines is performed, enabling the client a more detailed selection.
 *The investigation of the transport logistic has been proven that it will be possible to transport wind turbines in the 800 kW range. For bigger turbines, a detailed road survey has to be performed.
 *It can be expected that the delivery time for turbines in the Megawatt range will be longer when compared with smaller turbines.
 The specific investment costs in Euro per generated MWh per year for two selected 2 MW wind turbines compared to the 0.8 MW turbines of the same manufacturer are displayed in the following table:
@@ Line 127: / Line 121: @@
 This calculation is clearly showing the higher specific investment costs of the Multi-Megawatt-turbines compared to the 800 kW turbine class. If there is sufficient space available at the site (which is a limiting factor in most European sites today) to set up the installed capacity with smaller turbines like the 800 kW turbines in the example, a smaller turbine class could be a preferred choice, in case the transportation of large turbines to the site is difficult and connected to additional costs. Furthermore delivery time could be an important variable: Generally spoken smaller proven wind turbines have shorter delivery time as the large multi-megawatt machines. Thus, developers of a wind project have to conduct a small survey, which provider of wind turbines is able and willing to deliver the turbines to the country the project is located.<br/>
+<br/>
 === Turbine Distances / Micro-siting<br/> ===
@@ Line 135: / Line 129: @@
 For the Ashegoda wind project the minimal distances are summarized in the following table. As the wind turbines at this site should be erected in a single row, the distance of the turbines in the prevailing wind direction is not considered. If space is not a limiting factor for a wind park, the placement in a single row is very benificial because an important part of the wake effects can be avoided.<br/>
-{| border="0" align="left" cellspacing="1" cellpadding="1" style="height: 193px; width: 100%"
+{| border="0" align="left" cellspacing="1" cellpadding="1" style="height: 193px;  width: 100%"
 |+ Minimal turbine distances for Ashegoda wind park
 |-
 ! scope="col" | Turbine type<br/>
-! scope="col" colspan="2" | Minimal distance between turbines in cross wind direction<br/>
+! colspan="2" scope="col" | Minimal distance between turbines in cross wind direction<br/>
 |-
 ! scope="col" | <br/>
@@ Line 178: / Line 172: @@
 New studies show that the Frandsen-Model overestimates the turbulence applied to the turbines. The Empirical Turbulence Dutch TNO Laboratory 1993 Model could be chosen as alternatively. A consultation of the manufacturers of the wind turbines for checking the turbulence impact is generally required.<br/>
+<br/>
 = Noise Impact<br/> =
@@ Line 221: / Line 215: @@
 |}
 Considering that identified noise sensitive areas can be assigned to the Village centres with mixed utilisation, the limiting noise standard for the operation of the wind farm in the example of Ashegoda is an impact level of 45 dB (A) at night time.
 = Shadow Impact =
@@ Line 231: / Line 225: @@
 The estimations are carried out for the worst case that the sun is always shining, 365 days per year. An additional calculation can be performed using the real sunshine probability.
+<br/>
 = Further Information =
@@ Line 237: / Line 231: @@
 *[[Portal:Wind|Wind Portal on energypedia]]
+<br/>
 = References =

@@ Line 1: / Line 1: @@
-== Wind Potential Map<ref>The contents of this article have been prepared by the project team of the feasibility study of the Ethiopian wind park Ashegoda, conducted by the Deutsche Gesellschaft für internationale Zusammenarbeit (GIZ) in cooperation with the Austrian development agency and Lahmeyer international. Originally the contents have been published as: GTZ (2006) Feasibility Study for Wind Park Development in Ethiopia and Capacity Building - Ashegoda Wind Park Site), retrieved 11.7.2011 [[http://www.gtz.de/de/dokumente/en-feasibility-study-wind-park-ashegoda-2006.pdf]]</ref>  ==
+== Wind Potential Map<ref>The contents of this article have been prepared by the project team of the feasibility study of the Ethiopian wind park Ashegoda, conducted by the Deutsche Gesellschaft für internationale Zusammenarbeit (GIZ) in cooperation with the Austrian development agency and Lahmeyer international. Originally the contents have been published as: GTZ (2006) Feasibility Study for Wind Park Development in Ethiopia and Capacity Building - Ashegoda Wind Park Site), retrieved 11.7.2011 [[http://www.gtz.de/de/dokumente/en-feasibility-study-wind-park-ashegoda-2006.pdf]]</ref> ==
-Based on long-term corrected data of the [[Assessing wind potentials|wind measurements on site]], a wind potential map has been calculated (using [[Estimation of Wind Energy Production|WindPro and WAsP software]]), providing information for the distribution of the average wind speeds over the area foreseen for the implementation of the wind park (Figure 6-1) and therefore being a base for the wind park layout development process. Figure 1 shows an example for a wind potential map for the Ashegoda wind project in Ethiopia.
+Based on long-term corrected data of the [[Assessing_Wind_Potentials|wind measurements on site]], a wind potential map has been calculated (using [[Estimation of Wind Energy Production|WindPro and WAsP software]]), providing information for the distribution of the average wind speeds over the area foreseen for the implementation of the wind park (Figure 6-1) and therefore being a base for the wind park layout development process. Figure 1 shows an example for a wind potential map for the Ashegoda wind project in Ethiopia.
-[[Image:Wind Potential Map for Ashegoda wind project.jpg|frame|center|Figure 1: Wind potential map of Ashegoda site (red line indicates the road, orange areas mark the villages, yellow line the wind park area)]]<br>
+[[File:Wind Potential Map for Ashegoda wind project.jpg|frame|center|Figure 1: Wind potential map of Ashegoda site (red line indicates the road, orange areas mark the villages, yellow line the wind park area)]]
 == Wind Turbine Selection <br>  ==

@@ Line 1: / Line 1: @@
-== Wind Potential Map  ==
+== Wind Potential Map<ref>The contents of this article have been prepared by the project team of the feasibility study of the Ethiopian wind park Ashegoda, conducted by the Deutsche Gesellschaft für internationale Zusammenarbeit (GIZ) in cooperation with the Austrian development agency and Lahmeyer international. Originally the contents have been published as: GTZ (2006) Feasibility Study for Wind Park Development in Ethiopia and Capacity Building - Ashegoda Wind Park Site), retrieved 11.7.2011 [[http://www.gtz.de/de/dokumente/en-feasibility-study-wind-park-ashegoda-2006.pdf]]</ref>  ==
 Based on long-term corrected data of the [[Assessing wind potentials|wind measurements on site]], a wind potential map has been calculated (using [[Estimation of Wind Energy Production|WindPro and WAsP software]]), providing information for the distribution of the average wind speeds over the area foreseen for the implementation of the wind park (Figure 6-1) and therefore being a base for the wind park layout development process. Figure 1 shows an example for a wind potential map for the Ashegoda wind project in Ethiopia.
@@ Line 5: / Line 5: @@
 [[Image:Wind Potential Map for Ashegoda wind project.jpg|frame|center|Figure 1: Wind potential map of Ashegoda site (red line indicates the road, orange areas mark the villages, yellow line the wind park area)]]<br>
 In this map, it can be clearly seen that ridges in the west and and in the east have considerably more favourable wind conditions than the plain in between, caused by the shadowing effects of the ridges and the speed-up effect atop a hill. In this example military installations north of the road (red line) are limiting the wind park area to the region south of the road until it reaches the eastern ridges. The villages around the site (orange areas) are furthermore restricting the available space, as noise emissions from the wind turbines and the shadow flicker caused by the moving turbine rotors cause stress to the inhabitants of these villages if specific values are exceeded.<br>
 == Wind Turbine Selection <br>  ==

@@ Line 212: / Line 212: @@
 The estimations are carried out for the worst case that the sun is always shining, 365 days per year. An additional calculation can be performed using the real sunshine probability.
-== References ==
+== References  ==
 <references />

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