WIND FARM SYSTEM COMPRISING IMPROVED WIND GUIDE CONFIGURATION

Abstract

The present invention disclosure describes a wind farm system and a method to improve the energy production from a wind farm comprising one or more wind guides for speeding up the wind through the wind turbine rotor and thereby improving the energy production from the wind turbine. One wind guide covering several wind turbines or several wind guides with a limited gap between them have been proven to significantly improve the efficiency of wind guides. One or more wind guides covering the wind turbines in the last row of a wind farm has likewise shown unexpected significant improvements. CFD calculations have shown more than 40% improvement in generated power from a wind farm system in some cases.

Claims

1. A wind farm system comprising at least three contiguous wind turbines forming at least one row of wind turbines, such row(s) being substantially perpendicular to the predominant wind direction, and comprising wind guides for at least some of the wind turbines for blocking and thereby guiding the wind in front of the wind turbines from a first direction to a second direction; the wind turbines each comprising a tower and a rotor provided with a number of rotor blades defining a rotor swept area; the wind guides being ground-based, seabed-based or floating in the sea surface and with a horizontal length and a vertical height defining an area standing substantially vertically within a range of +/10 degrees; the wind guides being substantially arranged and configured to face the wind in the predominant wind direction and blocking the wind at an altitude below the rotor swept area and thereby directing the wind so the wind behind the wind guides has another direction and speed than the wind in front of the wind guides; each of the wind guides defining; the horizontal length between its two lateral ends not lower than 1 time the length of the closest wind turbine rotor diameter; the vertical height being constant or variable along the horizontal length but not lower than 3 meters and not higher than two thirds of the height of the closest wind turbine blade tip when positioned at its lowermost position; a horizontal width being constant or variable along the horizontal length of the wind guides but always lower than 1.5 times the height of the wind guides; each of the wind guides being substantially arranged and configured to block and thereby guide the wind at an altitude below the rotor swept area so the wind behind the wind guides has another direction and speed than the wind in front of the wind guides; each of the wind guides being substantially arranged and configured to direct the wind to an area in front of and/or behind the wind turbine rotor swept areas so that through the wind turbine rotor swept areas the wind speed is increased characterised in that a horizontal gap between the two closest ends of two contiguous wind guides is less than the sum of the lengths of the rotor diameters of the two wind turbines positioned closest to the two contiguous wind guides.

2. The wind farm system according to claim 1, characterised in that at least one of the wind guides is positioned at a distance from the wind turbine and at least one of the wind guides has no physical contact with the wind turbine.

3. The wind farm system according to claim 1, characterised in that throughout at least one of the swept areas of the wind turbine rotors the vertical wind shear is reduced and/or the turbulence intensity is reduced so that the fatigue loads onto the wind turbine blades are reduced.

4. The wind farm system according to claim 1, characterised in that the distance between any of the contiguous wind turbines' towers in the wind farm system is more than 1.0 and less than 1.1, 1.2, 1.3, 1.4, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5 or 10 wind turbine rotor diameters.

5. The wind farm system according to claim 1, characterised in that the wind farm system comprises at least two rows of wind turbines, such rows being substantially perpendicular to the predominant wind direction, and located substantially one row behind the other row considering the predominant wind direction, where the wind guides are located only at the last of the at least two rows of wind turbines in the wind farm system being such row located substantially downwind to the other row(s) of wind turbines in the wind farm system.

6. The wind farm system according to claim 5, characterised in that the average distance between the row of wind turbines with the wind guides and the row of wind turbines positioned upwind considering the predominant wind direction is at least 10% or 20% or 30% or 40% or 50% or 60% or 70% or 80% lower than the lowest distance between any other consecutive row in the wind farm system and thereby significantly reduce the land area needed for the wind farm system.

7. The wind farm system according to claim 1 characterised in that the wind farm system comprises only one row of wind turbines with wind guides.

8. The wind farm system according to claim 1 characterised in that the horizontal gap between the two closest ends of two contiguous wind guides is substantially zero meters forming a substantially or at least partly continuous wind guide for more than one wind turbine.

9. The wind farm system according to claim 1, characterised in that the wind farm system comprises at least 3, 4, 5, 7, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 120, 140, 160, 180, 200, 250, 300 wind turbines in each row.

10. The wind farm system according to claim 1, characterised in that the wind farm system comprises at least two wind guides with substantially different vertical heights so that the vertical height is highest closest to the ends of the row of wind turbines and the vertical height is lowest closest to the centre of the row of wind turbines.

11. The wind farm system according to claim 1, characterised in that the distance between the lowest position of the wind turbine rotor blade tips of each wind turbine rotor and its closest wind guide's top edges is different depending on the wind turbines relative position in the row of wind turbines with one or more wind guides.

12. The wind farm system according to claim 1, characterised in that the distance between the lowest position of the wind turbine rotor blade tips of each wind turbine rotor and its closest wind guide's top edges is lower closer to the ends of the row of wind turbines with one or more wind guides and is higher closer to the centre of the row of wind turbines with one or more wind guides.

13. The wind farm system according to claim 1, characterised in that the gap between two contiguous wind guides is located where a road, a river, or a path is located so that people, animals, ships, trucks, and any goods can pass through the gap.

14. The wind farm system according to claim 13, characterised in that the gap between the two contiguous wind guides comprises means to open and to close the gap either manually or automatically.

15. The wind farm system according to claim 1, characterised in that one or more wind guides are installed in front of existing wind turbines whereafter these existing wind turbines are at least partly replaced by new wind turbines that are exploiting the same existing one or more wind guides.

16. The wind farm system according to claim 1, characterised in that at least parts of at least some of the wind guides have a porosity more than 0, 5, 10, 20, 30, 40, 50, 60 percent.

17. The wind farm system according to claim 1, characterised in that the wind farm system further comprises an area to grow crops or an agri voltaic installation to both grow crops and generate photovoltaic power that benefit from the wind-breaking effect of the wind farm system.

18. A method to increase the energy production from a wind farm system comprising at least three contiguous wind turbines forming at least one row of wind turbines, such row(s) being substantially perpendicular to the predominant wind direction, and comprising wind guides for at least some of the wind turbines for blocking and thereby guiding the wind in front of the wind turbines from a first direction to a second direction; the wind turbines each comprising a tower and a rotor provided with a number of rotor blades defining a rotor swept area; the wind guides being ground-based, seabed-based or floating in the sea surface and with a horizontal length and a vertical height defining an area standing substantially vertically within a range of +/10 degrees; the wind guides being substantially arranged and configured to face the wind in the predominant wind direction and blocking the wind at an altitude below the rotor swept area and thereby directing the wind so the wind behind the wind guides has another direction and speed than the wind in front of the wind guides; each of the wind guides defining; the horizontal length between its two lateral ends not lower than 1 time the length of the closest wind turbine rotor diameter; the vertical height being constant or variable along the horizontal length but not lower than 3 meters and not higher than two thirds of the height of the closest wind turbine blade tip when positioned at its lowermost position; a horizontal width being constant or variable along the horizontal length of the wind guides but always lower than 1.5 times the height of the wind guides; each of the wind guides being substantially arranged and configured to block and thereby guide the wind at an altitude below the rotor swept area so the wind behind the wind guides has another direction and speed than the wind in front of the wind guides; each of the wind guides being substantially arranged and configured to direct the wind to an area in front of and/or behind the wind turbine rotor swept areas so that through the wind turbine rotor swept areas the wind speed is increased characterised in that a horizontal gap between the two closest ends of two contiguous wind guides is less than the sum of the lengths of the rotor diameters of the two wind turbines positioned closest to the two contiguous wind guides.

19. A method to expand an existing wind farm with one extra row of wind turbines with wind guides according to claim 18, characterised in that the average distance between the new extra row of wind turbines with the wind guides and the previous existing row of wind turbines positioned upwind considering the predominant wind direction is less than 90% or 80% or 70% or 60% or 50% or 40% or 30% of the distance between any other consecutive row(s) in the wind farm system and thereby significantly reduce the extra land area needed for expanding the existing wind farm.

20. A method to position wind turbines in a wind farm design that considers at least two rows of wind turbines positioned one upwind the other according to the predominant wind direction according to claim 18, characterised in that the most downwind row of wind turbines comprises wind guide(s) and according to this method, at least some of the wind turbines in each of the consecutive rows are positioned very close to each other (the turbines towers of contiguous turbines in the row being positioned at a distance less than 3 times the average rotor diameter of such contiguous turbines) minimizing the effect of prior turbines' wakes in the row downwind thanks to the wind flow optimizing effect of the wind guide(s).

Description

FIGURES

[0074] The invention will be better understood by reading the following description, given solely by way of non-limiting examples and with reference to the drawings, in which:

[0075] FIG. 1 shows a perspective front view of a wind farm system with gaps between the wind guides.

[0076] FIG. 2 shows a perspective front view of a wind farm system with one continuous wind guide to cover all the wind turbines.

[0077] FIG. 3 shows a side view of a wind turbine and a ground-based wind guide

[0078] FIG. 4 shows a perspective front view of a wind farm system with 3 rows of wind turbines and a continuous wind guide covering the last row.

[0079] FIG. 5 shows a perspective front view of a wind farm system with two wind guides each covering three wind turbines.

[0080] FIG. 6 shows a perspective front view of a wind turbine with a wind guide and streamlines showing the wind flow pattern.

[0081] FIG. 7 shows a front view of a wind turbine rotor swept area with a wind guide and streamlines showing the wind flow pattern.

[0082] FIG. 8 shows a top view of a wind farm system with 7 wind turbines and 7 wind guides.

[0083] FIG. 9 shows a top view of a wind farm system with 7 wind turbines and one wind guide.

[0084] FIG. 10 shows a top view of a wind farm system with 7 wind turbines and 7 wind guides.

[0085] FIG. 11 shows a top view of a wind farm system with 7 wind turbines and 1 wind guides.

[0086] FIG. 12 shows a front view of a wind farm system with 7 wind turbines and 7 wind guides.

[0087] FIG. 13 shows a front view of a wind farm system with 7 wind turbines and 1 wind guide.

[0088] FIG. 14 shows a top view of a wind turbine rotor swept area with a wind guide and streamlines showing the flow pattern.

[0089] FIG. 15 shows a top view of a wind turbine rotor swept area and 2 half parts of a wind turbine rotor swept area and a wind guide in full length and 2 half wind guides and streamlines showing the flow pattern.

[0090] FIG. 16 shows a side view of a wind turbine and a wind guide and contour lines illustrating the wind speed.

[0091] FIG. 17 shows a side view of a wind turbine and a wind guide and contour lines illustrating the wind speed.

LIST OF POSITIONS NUMBERS

[0092] 1 Wind Turbine [0093] 2 Wind Turbine Blade [0094] 3 Tower [0095] 4 Rotor Swept Area [0096] 5 Wind Direction [0097] 6 Wind Guide [0098] 7 Ground [0099] D Rotor Diameter [0100] G Gap Between the Two Closest Ends of Two Contiguous Wind guides [0101] h Distance Between the Ground and the Wind Turbine Rotors Lowest Blade Tip Height [0102] vh Vertical Height of the Wind guide. Measured as the Distance Between the Top of the Wind guide and the Ground or Sea Surface. [0103] d Distance Between the Position of the Lowest Blade Tip of the Wind Turbine Rotor and the Closest Wind guide Top Edge [0104] d1 Projection in the horizontal plane of the distance Between the Position of the Lowest Blade Tips of the Wind Turbine Rotors and the Closest Wind guides Top Edge [0105] d2 Projection in the horizontal plane of the distance Between the Position of the Lowest Blade Tips of the Wind Turbine Rotors and the Closest Wind guides Top Edge [0106] d3 Projection in the horizontal plane of the distance Between the Position of the Lowest Blade Tips of the Wind Turbine Rotors and the Closest Wind guides Top Edge [0107] d4 Projection in the horizontal plane of the distance Between the Position of the Lowest Blade Tips of the Wind Turbine Rotors and the Closest Wind guides Top Edge [0108] d5 Projection in the horizontal plane of the distance Between the Position of the Lowest Blade Tips of the Wind Turbine Rotors and the Closest Wind guides Top Edge [0109] d6 Projection in the horizontal plane of the distance Between the Position of the Lowest Blade Tips of the Wind Turbine Rotors and the Closest Wind guides Top Edge [0110] d7 Projection in the horizontal plane of the distance Between the Position of the Lowest Blade Tips of the Wind Turbine Rotors and the Closest Wind guides Top Edge [0111] h1 Vertical Height of a Wind guide [0112] h2 Vertical Height of a Wind guide [0113] h3 Vertical Height of a Wind guide [0114] h4 Vertical Height of a Wind guide [0115] h5 Vertical Height of a Wind guide [0116] h6 Vertical Height of a Wind guide [0117] h7 Vertical Height of a Wind guide [0118] h8 Vertical Height of a Wind guide [0119] h9 Vertical Height of a Wind guide

DETAILED DESCRIPTION

[0120] In FIG. 1 is shown a perspective front view of a wind farm system with 6 wind turbines (1) and 6 wind guides (6) with horizontal gaps (G) between each of the wind guides (6). The horizontal gaps (G) are, according to the invention, less than the sum of the lengths of the rotor diameters (D) of the two wind turbines positioned closest to the two contiguous wind guides. At the drawing all wind turbines have identical rotor diameters (D), so in this case, the horizontal gaps are less than 2 times the rotor diameter (D) of one wind turbine (1). The wind direction is shown with 3 arrows pointing in the direction the wind flows.

[0121] In FIG. 2 is shown a perspective front view of a wind farm system with 6 wind turbines (1) and one continuous wind guide (6) to cover all the 6 wind turbines. There are no horizontal gaps between the wind guides or the horizontal gaps are zero. According to the invention, the horizontal gaps are less than the sum of the lengths of the rotor diameters of the two wind turbines positioned closest to the two contiguous wind guides. In this case the horizontal gaps are zero, so this case is covered by the invention disclosure, since zero is less than 2 times the rotor diameter of one of the identical wind turbines.

[0122] In FIG. 3 is shown a side view of a wind turbine (1) and a ground-based wind guide (6). The wind guide (6) could as well be seabed-based or floating on the sea surface and it is substantially vertically oriented, although it could as well be angled up to 10 degrees to each side. The wind guide could have, as according to this invention disclosure, a vertical height (vh) that is between one third and two thirds of the distance between the ground, seabed, or the sea surface and the wind turbine rotors lowest blade tip height. The distance (d) between the lower blade tip position and the wind guide top edge is also shown in the figure, since this distance is used in FIGS. 8-13. The wind turbine rotors lowest blade tip height means the lowest point of the wind turbine rotor swept area and therefore the lowest vertical position the blade tips will take when the wind turbine rotor is rotating. The wind guide is, in FIG. 3, positioned at a distance in front of the wind turbine (the wind direction is from right to left and it is not shown in FIG. 3) but it could as well be aligned with the wind turbine tower and thereby substantially speed-up the wind behind the rotor swept area and thereby substantially speed-up the wind through the wind turbine rotor to increase the power production from the wind turbine.

[0123] In FIG. 4 is shown a perspective front view of a wind farm system with 3 rows of 6 wind turbines (1) in each row and a continuous wind guide (6) covering the last row being the row downwind in relation to the other two rows in the wind farm. This is in accordance with this invention disclosure, where the wind farm system comprises at least two rows of wind turbines substantially parallel to each other and located substantially one behind the other considering the predominant wind direction, where the wind guides are located only at the last row of wind turbines in the wind farm system being such row located downwind to the other rows of wind turbines in the wind farm considering the predominant wind direction. CFD calculations of the set-up shown in FIG. 4, have shown surprisingly good results since the wind flow will be influenced by one or two wind turbines before it reaches the wind turbines with the wind guide in the last row. CFD calculations have also shown that, the speed-up of the wind around the wind turbine rotors bottom part in the 2 front rows caused by the induction that is caused by the operating wind turbines extracting energy from the wind in the front rows, is the main reason for the higher speed-up by the wind guide located in the last row compared to a case where the wind turbines with the wind guide were in a single row wind farm. This front wind turbine induced speed-up effect is combined with the effect originating from a wind guide.

[0124] In FIG. 5 is shown a perspective front view of a wind farm system with 6 wind turbines (1) and two wind guides (6) each covering three wind turbines. This is in accordance with this invention disclosure where at least two contiguous wind guides connect through its closest ends to form one substantially continuous wind guide. The higher the number of wind turbines sharing one continuous wind guide, the better the effect to increase the wind speed-up effect compared to a single wind turbine with one wind guide. When 3 or more wind turbines share one continuous wind guide, this effect is significant. Also, there could be reasons for designing exceptionally long wind guides with gaps for local farmers, animals or wind turbine service personnel and equipment to easily pass through to the other side of the wind guide and there could be cases where roads go through a wind farm with wind guides.

[0125] In FIG. 6 is shown a perspective front view of a wind turbine (1) with a wind guide (6) and streamlines showing the wind flow pattern. As described previously, the solution with a single wind turbine with a single wind guide substantially show two major aerodynamic losses where FIG. 6 show one of them. It is shown how a considerable amount of wind flow escape at the two ends of the wind guide and thereby lose wind flow that, as according to the present invention disclosure, can be reduced and thereby improve the wind speed increase for two or more contiguous wind turbines.

[0126] In FIG. 7 is shown a front view of a wind turbine rotor swept area (4) with a wind guide (6) and streamlines showing the wind flow patterns. As described previously, the solution with a single wind turbine with a single wind guide substantially show two major aerodynamic losses, where FIG. 7 shows one of them. It is shown that the wind leaving the wind guide diverge to the two sides in front of the rotor swept area. This divergence of the flow result in a reduced wind speed passing through the rotor as compared to a flow where there is no or little divergence of the wind flow in front of the wind turbine rotor swept area. In case 9 contiguous wind turbines share the same continuous wind guide, this flow divergence will be small and the efficiency of the wind guide to speed-up the wind will be improved as according to the present invention disclosure. In the case of infinite number of wind turbines sharing the same continuous wind guide, the wind flow would be 2-dimensional and there would be no flow divergence.

[0127] In FIG. 8 is shown a top view of a wind farm system with 7 wind turbines represented by the projection in the horizontal plane of the rotor swept area (4) and 7 wind guides (6) with a gap (G) between them and the wind farm system is in a special layout. This layout is in accordance with the disclosure of the present invention where the distance between the position of the lowest wind turbine rotor blade tips of the wind turbine rotors and the closest wind guides top edges are different depending on the wind turbines relative position in a row of wind turbines with one or more wind guide(s). In FIG. 8 the projections in the horizontal plane of such distances are named d1 to d7 and in a preferred solution as shown in FIGS. 8, d1 d2 d3 d4 and d4 d5 d6 d7 since CFD calculations have shown this to be an optimum solution for a wind farm system situated in a flat area with low surface roughness.

[0128] In FIG. 9 is shown a top view of a wind farm system with 7 wind turbines represented by the projection in the horizontal plane of the rotor swept area (4) and one continuous wind guide (6) covering all 7 wind turbines in a special layout. This layout is in accordance with the disclosure of the present invention where the distance between the position of the lowest wind turbine rotor blade tips of the wind turbine rotors and the closest wind guides top edges are different depending on the wind turbines relative position in a row of wind turbines with one or more wind guide(s). In FIG. 9 the projections in the horizontal plane of such distances are named d1 to d7 and in a preferred solution as shown in FIGS. 9, d1 d2 d3 d4 and d4 d5 d6 d7, since CFD calculations have shown this to be an optimum solution for a wind farm system situated in a flat area with low surface roughness.

[0129] In FIG. 10 is shown a top view of a wind farm system with 7 wind turbines represented by the projection in the horizontal plane of the rotor swept area (4) and 7 wind guides (6) with a gap (G) between them. The layout is typical for an existing wind farm, where the wind turbines are situated in a row forming a straight line and where the wind guides are not situated in one straight line. This layout is in accordance with the disclosure of the present invention where the distance between the position of the lowest wind turbine rotor blade tips of the wind turbine rotors and the closest wind guides top edges are different depending on the wind turbines relative position in a row of wind turbines with one or more wind guide(s). In FIG. 10, the projections in the horizontal plane of such distances are named d1 to d7 and in a preferred solution as shown in FIGS. 10, d1 d2 d3 d4 and d4d5 d6d7, since CFD calculations have shown this to be an optimum solution for a wind farm system situated in a flat area with low surface roughness.

[0130] In FIG. 11 is shown a top view of a wind farm system with 7 wind turbines represented by the projection in the horizontal plane of the rotor swept area (4) and 1 wind guides (6). The layout is typical for an existing wind farm, where the wind turbines are situated in a row forming a straight line. The wind guide is curved to optimize the position of the wind guide relative to the position of the wind turbines. This layout is in accordance with the disclosure of the present invention where the distance between the position of the lowest wind turbine rotor blade tips of the wind turbine rotors and the closest wind guides top edges are different depending on the wind turbines relative position in a row of wind turbines with one or more wind guide(s). In FIG. 11 the projections in the horizontal plane of such distances are named d1 to d7 and in a preferred solution as shown in FIGS. 11, d1 d2 d3 d4 and d4 d5 d6 d7, since CFD calculations have shown this to be an optimum solution for a wind farm system situated in a flat area with low surface roughness.

[0131] In FIG. 12 is shown a front view of a wind farm system with 7 wind turbines represented by their rotor swept area (4) and the tower (3) and 7 wind guides (6) positioned with a gap (G) between them and in front of the wind turbines. This layout is in accordance with the disclosure of the present invention where the wind farm system comprises wind guide(s) with different vertical height(s). In FIG. 12 these vertical heights are named h1 to h7 and in a preferred solution as shown in FIGS. 12, h1h2h3h4 and h4 h5 h6 h7, since CFD calculations have shown this to be an optimum solution for a wind farm system situated in a flat area with low surface roughness.

[0132] In FIG. 13 is shown a front view of a wind farm system with 7 wind turbines represented by their rotor swept area (4) and the tower (3) and 1 continuous wind guide (6) covering all the 7 wind turbines. This layout is in accordance with the disclosure of the present invention where the wind farm system comprises wind guide(s) with different vertical height(s). In FIG. 13 these vertical heights are local vertical heights at different positions of the continuous wind guide and the heights are named h1 to h9 and in a preferred solution as shown in FIGS. 13, h1h2h3h4h5 and h5 h6 h7 h8 h9, since CFD calculations have shown this to be an optimum solution for a wind farm system situated in a flat area with low surface roughness.

[0133] In FIG. 14 is shown a top view of a wind turbine rotor swept area (4) with a wind guide (6) and streamlines showing the flow pattern. The wind flow (5) starts from the left side and flows towards the right side and the starting height position for the streamlines in the far-left side is 8-meter height above ground or sea surface. One 165 meter long and 16 meters high wind guide is positioned in front of the wind turbine rotor swept area. In this CFD calculation the actuator disk function is turned off, so the flow is not influenced by the induction caused by the wind turbine rotor and the 90 meters diameter wind turbine rotor swept area is, therefore only included in the figure to show the position where the wind turbine rotor may be located. In case the actuator disk was included to model the induction from the wind turbine rotor, the horizontal divergence of the flow just in front of the wind turbine rotor swept area would have shown a larger divergence of the wind flow. This divergence is one of the two aerodynamic losses that are exceptionally large for a single wind turbine with a single wind guide, as shown in FIG. 14. The other exceptionally large aerodynamic loss is caused by the wind flow escaping at the two ends of the wind guide. The streamlines behind the two ends of the wind guide are very closely spaced indicating a relatively high wind speed indicating a relatively large aerodynamic loss since the wind flow that escapes at the ends of the wind guide will not be exploited to speed-up the wind flow at the wind turbine rotor height and therefore it is to be considered as a total aerodynamic loss. The main option in the present invention disclosure is to reduce these two aerodynamic losses and thereby improve the efficiency of the wind guide.

[0134] FIG. 15 shows a top view of a wind turbine rotor swept area (4) and 2 half parts of a wind turbine rotor swept area (4) and a wind guide (6) in full length and 2 half wind guides (6) and streamlines showing the flow pattern. The wind flow (5) starts from the left side and flows towards the right side and the starting height position for the streamlines in the far-left side is 8-meter height above ground or sea surface. One 165 meter long and 16 meters high wind guide is positioned in front of the wind turbine rotor swept area at the centre of FIG. 15.

[0135] The horizontal gaps (G) between the closest ends of two contiguous wind guides is 15 meters. In the CFD calculation 9 wind identical wind turbines with 9 identical wind guides was simulated. In FIG. 15 only the centre wind turbine with its wind guide and two half parts of the wind turbines with their wind guide systems are shown. In this CFD calculation the actuator disk function is turned off, so the flow is not influenced by the induction caused by the wind turbine rotors and the 90 meters diameter wind turbine rotor swept areas are, therefore only included in the figure to show the position where the wind turbine rotors may be located. When comparing the flow pattern between FIG. 14 and FIG. 15 it is obvious that both the wind flow divergence and the wind flow escaping at the ends of the wind guide is much smaller in the case showing the centre positioned wind guide out of 9 wind guides as shown in FIG. 15. Therefore, it is obvious that the total aerodynamic loss is much larger for a single wind guide than for a row of 9 wind guides with dimensions as described above, when the wind guides are positioned with a 15-metre horizontal gap between them. The main option in the present invention disclosure is to reduce the aerodynamic losses and thereby improve the efficiency of the wind guide.

[0136] In FIG. 16 is shown a side view of a wind turbine represented by its rotor swept area (4) and a wind guide (6) and contour lines illustrating the wind speed. The wind flow (5) comes from the left side and flows towards the right side in FIG. 16. One 165 meter long and 16 meters high wind guide is positioned in front of the wind turbine rotor swept area. In this CFD calculation the actuator disk function is turned off, so the flow is not influenced by the induction caused by the wind turbine rotor and the 90 meters diameter wind turbine rotor swept area is, therefore only included in the figure to show the position where the wind turbine rotor may be located. The contour lines show the horizontal component of the wind speed and it can be seen that in the wake behind the wind guide, the wind flow is negative, indicating that the wind flow flows from right to left in the figure. For example, the contour line 1 show a wind speed at 2.5 m/s. The contour line 7 show the line where the wind speed is 9.5 m/s. Above this line the wind speed is higher than 9.5 m/s. The influence from the wind guide has a positive effect on the wind speed both from the top, where the 9.5 m contour line drops down into the rotor swept area and from the 7.5 m/s contour line that rises into the rotor swept area.

[0137] In FIG. 17 is shown a side view of a wind turbine represented by its rotor swept area (4) and a wind guide (6) and contour lines illustrating the wind speed. The wind flow comes from the left side and flows towards the right side in FIG. 17. One 165 meter long and 16 meters high wind guide is positioned in front of the wind turbine rotor swept area. In this CFD calculation the actuator disk function is turned off, so the flow is not influenced by the induction caused by the wind turbine rotor and the 90 meters diameter wind turbine rotor swept area is, therefore only included in the figure to show the position where the wind turbine rotor may be located. The contour lines show the horizontal component of the wind speed similar to those shown in FIG. 16. The input data for the CFD calculation are identical to the input data used to calculate the result shown in FIG. 15. FIG. 17 show the results when including 9 wind turbines and 9 wind guides with a 15-meter gap between the two contiguous ends of the wind guides. In FIG. 17 the horizontal wind speed is much higher at the wind turbine rotor swept area than in the single wind turbine case shown in FIG. 16. The 9.5 m/s contour line covers almost the entire wind turbine rotor swept area, whereas in FIG. 16 it only covers less than half the wind turbine rotor swept area.

Items

[0138] 1. A wind farm system comprising at least two neighbouring wind turbines forming at least one row of wind turbines that is substantially perpendicular to the most predominant wind direction and at least two wind guides for guiding the wind in front of each of the at least two neighbouring wind turbines from a first direction to a second direction; [0139] the neighbouring wind turbines comprising a tower and a rotor provided with a number of rotor blades defining a rotor swept area; [0140] the wind guides comprising a wind guide with a horizontal length, at least one vertical height, a horizontal width and with at least two ends, arranged and configured to receive wind from an altitude below the rotor swept area and to direct the wind so the wind leaving the wind guide has another direction than the wind received by the wind guide; [0141] the wind guides are arranged and configured to direct the wind to an area in front of and/or behind the wind turbine rotors' swept area in a way that through such rotors' swept area the wind speed is increased characterised in that the horizontal gap between the two closest ends of two contiguous wind guides is less than the sum of the length of the rotor diameters of the two wind turbines positioned closest to the two contiguous wind guides. [0142] 2. The wind farm system according to item 1, characterised in that at least two contiguous wind guides connect through its closest ends to form one substantially continuous wind guide. [0143] 3. The wind farm system according to any of the items 1-2, characterised in that the wind guide(s) is (are) ground-based or seabed-based and is (are) substantially vertical within a range of +/10 degrees. [0144] 4. The wind farm system according to any of the items 1-3, characterized in that the wind guide(s) has (have) a vertical height between one third and two thirds of the distance between the ground or the sea surface and the wind turbine rotors lowest blade tip height. [0145] 5. The wind farm system according to any of the items 1-4, characterised in that the distance between at least two of the wind turbines in said wind farm system is less than 1.1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5 or 10 wind turbine rotor diameters. [0146] 6. The wind farm system according to any of the items 1-5, characterised in that said wind farm system comprises at least two rows of wind turbines substantially parallel to each other and located substantially one behind the other considering the predominant wind direction, where the wind guides are located only at the last row of wind turbines in the wind farm system being such row located downwind to the other rows of wind turbines in the wind farm considering the predominant wind direction. [0147] 7. The wind farm system according to any of the items 1-5 characterised in that said wind farm system comprises only one row of wind turbines and only one wind guide covering at least two of the wind turbines in the one row of wind turbines. [0148] 8. The wind farm system according to any of the items 1-7, characterised in that said wind farm system comprises at least 3, 4, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 120, 140, 160, 180, 200, 250, 300, 350, 400, 450 or 500 wind turbines. [0149] 9. The wind farm system according to any of the items 1-8, characterised in that the wind farm system comprises wind guide(s) with different vertical height(s). [0150] 10. The wind farm system according to any of the items 1-9, characterised in that the distance between the position of the lowest wind turbine rotor blade tips of the wind turbine rotors and the closest wind guides top edges are different depending on the wind turbines relative position in a row of wind turbines with one or more wind guide(s). [0151] 11. The wind farm system according to any of the items 1-10, characterised in that the wind guide(s) further incorporate(s) solar panels to enable the production of hybrid wind-solar energy generation. [0152] 12. The wind farm system according to any of the items 1-11 characterised in that the wind guide(s) comprise(s) visual impact improvement devices or means to improve the visual impact caused by the wind guide(s). [0153] 13. A method to increase the energy production from a wind farm system comprising at least two neighbouring wind turbines forming at least one row of wind turbines that is substantially perpendicular to the most predominant wind direction and at least two wind guides for guiding the wind in front of each of the at least two neighbouring wind turbines from a first direction to a second direction; [0154] the neighbouring wind turbines comprising a tower and a rotor provided with a number of rotor blades defining a rotor swept area; [0155] the wind guides comprising a wind guide with a horizontal length, at least one vertical height, a horizontal width and with at least two ends, arranged and configured to receive wind from an altitude below the rotor swept area and to direct the wind so the wind leaving the wind guide has another direction than the wind received by the wind guide; [0156] the wind guides are arranged and configured to direct the wind to an area in front of and/or behind the wind turbine rotors' swept area in a way that through such rotors' swept area the wind speed is increased characterised in that the horizontal gap between the two closest ends of two contiguous wind guides is less than the sum of the length of the rotor diameters of the two wind turbines positioned closest to the two contiguous wind guides.