WO2023057026A1

WO2023057026A1 - Pressure vessels for a wind turbine foundation

Info

Publication number: WO2023057026A1
Application number: PCT/DK2022/050205
Authority: WO
Inventors: Mogens Jensen
Original assignee: Mogens Jensen
Priority date: 2021-10-06
Filing date: 2022-10-05
Publication date: 2023-04-13

Abstract

The present invention relates to a wind turbine foundation, the wind turbine foundation comprising one or more pressure vessels (90) as a solid support (23) for a wind turbine (10), the one or more pressure vessels (90) being equipped with fastening means (92) for keeping a wind turbine (10) in position during operation. The one or more pressure vessels (90) are adapted to be positioned beneath the ground at least partly in replacement of a concrete foundation for a wind turbine (10), and the one or more pressure vessels (90) are adapted for containing potential energy generated during periods when excess electrical energy is produced by a wind turbine (10) and configured to release energy during periods when inadequate electrical energy is produced by a wind turbine (10). Also, the one or more pressure vessels (90) are communicably coupled to one or more air compressors for storing potential energy generated during periods when excess electrical energy is produced by a wind turbine (10).

Description

PRESSURE VESSELS FOR A WIND TURBINE FOUNDATION

FIELD OF THE INVENTION

The present invention relates to the field of energy storage for wind turbines and particularly to a wind turbine foundation for storage of compressed air.

BACKGROUND OF THE INVENTION

In recent years there has been more and more attention to means for storing energy for use when wind turbines are less productive, such as during periods of low wind or nearly windless conditions. One of the great challenges of modern wind turbines and wind farms is that periods of low wind speed or windless periods often result in very low energy production because wind turbines usually cannot operate during these periods and are frequently set out of function during these wind conditions.

Several attempts have been described in terms of storing energy during periods of high performance of wind turbines or wind farms. These attempts include conversion of excess wind energy to basalt stones by heating the stones and utilizing the heat during periods of low wind speed or windless periods.

However, this solution may have some pronounced challenges. One of these challenges include a low efficiency in converting wind energy into another type of energy and further into electrical energy during high demands. Another challenge is that basalt stones may not suffice the demands on site and may not always be available in the quantity required on site, especially not on sites with restrictions, such as for off-shore wind turbines positioned on the sea ground.

Conventional horizontal-axis wind turbines are particularly challenged by low wind speed or windless periods since large scale wind blades are often not suitable for running under these wind conditions. Hence, solutions to accommodate the problems of energy storage of this type of wind turbines is gaining more and more attention, and a solution may fulfill a long felt need in the wind turbine business since a major part of wind turbines commonly used are horizontal-axis wind turbines.

Also, with respect to vertical-axis wind turbines there is a need for solutions to the ever growing problem of energy shortage during periods of low or no wind.

Although these types of wind turbines may operate at lower wind speed, there would still be a need for supplemental energy production at these wind speeds in order to supply high demands. Additionally, windless periods are still a challenge, and solutions that may accommodate production of energy during windless periods would be highly desirable.

Accordingly, there is a need in the art for energy storage means that may satisfy the demand for electrical energy during periods of low wind or windless periods. Further, there is a need in the art for energy storage solutions that are more cost- effective and energy efficient as well as solutions that only require a limited space.

SUMMARY OF THE INVENTION

Accordingly, there is provided a wind turbine foundation, the wind turbine foundation comprising: one or more pressure vessels (90) as a solid support (23) for a wind turbine (10), the one or more pressure vessels (90) being equipped with fastening means (92) for keeping a wind turbine (10) in position during operation, wherein the one or more pressure vessels (90) are adapted to be positioned beneath the ground at least partly in replacement of a concrete foundation for a wind turbine (10); the one or more pressure vessels (90) are adapted for containing potential energy generated during periods when excess electrical energy is produced by a wind turbine (10) and configured to release energy during periods when inadequate electrical energy is produced by a wind turbine (10); and the one or more pressure vessels (90) are communicably coupled to one or more air compressors for storing potential energy generated during periods when excess electrical energy is produced by a wind turbine (10).

Due to a very high loading capacity, a foundation comprising one or more pressure vessels (90) is considered very beneficial according to embodiments of the invention. For instance, multiple pressure vessels of 4.5 times 16 meters may be applied in the foundation of a wind turbine, such as 4-25 vessels, such as 5-20 vessels, such as 8-16 vessels depending on the requirements. Presently preferred is pressure vessels that may easily be transported to the site, here 4.5 times 16 meters. However, the size may be less or higher depending on requirement to the foundation or the transportation possibilities, such as 2 times 25 meters, such as 2.5 times 22 meters, such as 3 times 20 meters, such as 4 times 18 meters. Alternatively, 0.2 times 3 meters, such as 1.3 times 2 meter, such as 1.0 times 1.5 meters.

Importantly, a foundation mainly comprised of pressure vessels may solve various problems of energy storage for conventional wind turbine foundations. This type of foundation may be used for conventional horizontal-axis wind turbines or verticalaxis wind turbines according to the invention. The compressed air may be utilized to operate the one more wind rotors as for pressure vessels located in the housing of a wind turbine or may via converting means be used to operate one or more gearboxes and/or one or more generators. Particularly, a foundation may be provided with cylindrical pressure vessels in the foundation, preferable using no or a very low amount of supporting concrete. These pressure vessels may work as solid support for the wind turbine, i.e., as foundation.

In an embodiment of the invention, the foundation may comprise means for anchoring the one or more pressure vessels (90) beneath the ground. Additionally, fastening means (92) for keeping the wind turbine (10) in position during operation may be provided, such as rails for allowing the wind turbine (10) to rotate at least partly around an axis during operation. In some embodiments, the one or more pressure vessels (90) may comprise multiple pressure vessels (90). Compared to other types of storage means, compressed air according to the invention may be stored for a very long time, such as weeks, months or even years.

In some embodiments, the fastening means (92) for keeping a wind turbine (10) in position during operation comprise rails for allowing the wind turbine (10) to rotate at least partly around an axis during operation.

In some embodiments, the one or more pressure vessels (90) may have a working pressure of 5 bars or more, such as 10 bars or more, such as 20 bars or more, such as 50 bars or more.

In some embodiments, the one or more pressure vessels (90) may have a capacity of 10.000 liters or more, such as 50.000 liters or more, such as 100.000 liters or more, such as 200.000 liters or more, such as 250.000 liters or more, such as 300.000 liters or more.

However, also with respect to vertical-axis wind turbines there is a need for solutions to the ever growing problem of energy shortage during periods of low or no wind. Although these types of wind turbines may operate at lower wind speed, there would still be a need for supplemental energy production at these wind speeds in order to supply high demands. Additionally, windless periods are still a challenge, and solutions that may accommodate production of energy during windless periods would be highly desirable.

In some embodiments, the foundation may comprise multiple pressure vessels (90) communicably coupled to each other and communicably coupled to one or more air compressors for storing potential energy generated during periods when excess electrical energy is produced by the wind turbine (10).

In certain aspects of the invention, there is provided a wind turbine system for storage of wind energy, the wind turbine system comprising: a tower structure (10) having one or more wind rotors (40) with at least one wind blade (50), such as at least two or three wind blades, one or more generators for converting wind energy to electrical energy, optionally one or more gearboxes, one or more air compressors, and a wind turbine foundation comprising one or more pressure vessels (90) as a solid support (23) for the tower structure (10), the one or more pressure vessels (90) being equipped with fastening means (92) for keeping the tower structure (10) in position during operation, wherein the one or more pressure vessels (90) are adapted to be positioned beneath the ground at least partly in replacement of a concrete foundation for the tower structure (10); the one or more pressure vessels (90) are adapted for containing potential energy generated during periods when excess electrical energy is produced by the tower structure (10) and configured to release energy during periods when inadequate electrical energy is produced by the tower structure (10); and the one or more pressure vessels (90) are communicably coupled to one or more air compressors for storing potential energy generated during periods when excess electrical energy is produced by the tower structure (10).

In certain embodiments of this aspect, the tower structure (10) may comprise: a housing (15) having a front area (17) operable to receive ambient wind for generation of wind energy, a back area (19) operable to point away from the ambient wind direction, a bottom area (21) adapted to be fastened to a solid support (23), a top area (25) positioned in a certain height from the bottom area (21), and side areas (27,29) with one or more openings (33) operable to expel excess wind from the housing (15), the housing (15) comprising: one or more wind rotors (40) extending substantially from the bottom to the top of the housing (15) having vertical axes relative to the ground and each comprising at least one wind blade (50), such as at least two or three, the one or more wind rotors (40) being operable to receive wind from the front area (17) of the housing (15) and expel excess wind through the side areas (27,29); and at least two wind guiding members (55), such as at least three or four, for each of the one or more wind rotors (40) adapted to capture and guide ambient wind from outer positions within the front area (17) of the housing (15) to each of the one or more wind rotors (40), enabling the one or more wind rotors (40) to rotate with an increased speed and/or invoking increased wind force on the one or more wind rotors (40).

While little efforts have been given to vertical-axis wind turbines in recent years, certain clear benefits may apply to these types of wind turbines compared to horizontal-axis wind turbines. Among these advantages are the ability to generate energy from closer to the ground compared to horizontal-axis wind turbines and easy access for maintenance of gearboxes and generators that may be located close to the ground. However, as transportation challenges often limit the dimensions of these vertical-axis constructions, full benefit is not always achieved by the hitherto known vertical-axis wind turbines.

Generally, when reference is made to a “vertical-axis wind turbine” or similar wordings, the intended meaning is a wind turbine with one or more rotors operating around an axis transversely to the wind, contrary to a horizontal-axis wind turbine where a shaft or axis usually is positioned in parallel to the wind direction as would be understood by a person skilled in the art. A horizontal-axis wind turbine may be applied in some embodiments of the invention, such as in embodiments including energy storage of compressed air.

Typically, the vertical-axis wind turbine operates along a vertical axis where one or more wind rotors move horizontally around a vertical axis generating energy by rotation. In some embodiments, the vertical axis comprises one or more shafts, and in some embodiments the vertical axis comprises one or more hollow tube structures fixed at certain points to the housing of the wind turbine structure. One single shaft may be provided for one axis, or multiple shafts joined together in various joints may be provided for one axis. The same applies for the one or more hollow tube structures when applied, i.e., a single structure may be provided for each axis or multiple structures may be provided for each axis as needed. In some embodiments, the one or more wind rotors may on the vertical axis may be positioned such that the one or more wind blades have the same angle to each other. In some embodiments, the one or more wind rotors may on the vertical axis may be positioned such that the one or more wind blades have a different angle to each other. Other arrangements would also be available.

In certain other embodiments of this aspect, the tower structure (10) may comprise: one or more adjustable extensions (60,61) on each side of the housing (15), extending substantially from the bottom to the top of the housing (15), wherein the front (66) of said extensions (60,61) is adapted to increase the area for capturing and guiding ambient wind from positions outside the housing (15) to each of the one or more wind rotors (40), and wherein the back (68) of said extensions (60,61) is adapted to allow expelled excess wind from the side areas (27,29) of the housing (15) to proceed in a distance X outside the tip (62,63) of said extensions (60,61), thereby shifting the area for capturing and guiding ambient wind to positions outside the tip (62,63) of said extensions (60,61). In certain additional embodiments of this aspect, the housing (15) may comprise one or more back wind guiding members (57), such as adjustable wind guiding members (57), adapted to capture and guide excess wind after passing the one or more wind rotors (40) through the one or more openings (33) of the side areas (27,29) to the back (68) of said extensions (60,61), whereby expelled excess wind is forced and directed to proceed in a distance X outside the tip (62,63) of said extensions (60,61).

In some embodiments of this aspect, the tower structure (10) comprises one or more adjustable extensions (60,61) on each side of the housing (15), extending substantially from the bottom to the top of the housing (15), wherein said extensions (60,61) are operable to generate a higher pressure at the front (66) of said extensions (60,61) relative to the back (68) of said extensions (60,61) during operation, thereby generating a pressure difference between the front area (17) and the back area (19) of the housing (15) enabling the one or more wind rotors (40) to rotate with a pressure driven increased speed and/or invoking a pressure driven increased wind force on the one or more wind rotors (40).

Particularly, while the one or more rotors of the wind turbine of the present invention may be operated by direct exposure to ambient wind on the rotor blades, the pressure difference generated by means of the one or more extensions according to the invention may establish an even more efficient utilization of the wind energy.

Accordingly, the efficiency of energy production is even further improved by the presence of the one or more extensions according to the invention.

Specifically, it is contemplated that the relative low pressure on the backside of the housing of the wind turbine compared to the higher pressure on front of the housing of the wind turbine provides a synergistic effect in terms of rotation of the one or rotors according to the invention. This is especially pronounced in conditions of low ambient wind speed, where a relatively high pressure difference may be generated between the front and backside of the one or more adjustable extensions, which may provide a synergistic higher utilization of the wind energy. In some embodiments, the one or more adjustable extensions (60,61) are bending backwards in a way such that the tips (62,63) of said extensions (60,61) are positioned in a distance behind the back area (19) of the housing (15) relative to a horizontal axis extending centrally from the front area (17) to the back area (19) of the housing (15).

Particularly, it was seen that an increased pressure difference over the front and back side of the one or more extensions according to the invention may be generated by a configuration where the one or more adjustable extensions are bend backwards, for instance when the tips of the one or more extensions are positioned in a distance behind the back of the housing of the wind turbine. Without being bound by theory it is contemplated that the “cavity” defined by the one or more adjustable extensions allows for a higher pressure difference, which in turn invokes more speed of the one or more rotors of the wind turbine.

In some embodiments of the invention, the vertical-axis wind turbine is rotatable around a horizontal axis and the one or more adjustable extensions (60,61) are configured in a way that allows the vertical-axis wind turbine to adjust so that the front area (17) of the housing (15) is automatically pointing toward the ambient wind direction during operation.

While rotating may be accommodated by a means for rotation, such as an electrically driven engine means, it is particularly advantageous for smaller wind turbines for use in households or the like that the windmill may automatically adjust to the wind direction. Also, upon changing wind directions, it may be advantageous with an agile and quickly adapting wind turbine that may generate wind energy even in conditions with changing conditions.

In some embodiments of the invention, the one or more adjustable extensions (60,61) comprise a telescopic arrangement (64) so that the one or more adjustable extensions (60,61) are extendible in an outwards direction, thereby allowing a higher pressure difference between the front area (17) and the back area (19) of the housing (15) during operation even at low ambient wind speeds.

Various advantages are associated with a telescopic arrangement of the one or more adjustable extensions. One of these advantages is that an increased area may be established by extending the one or one adjustable extensions as much as possible, thereby increasing the area on front and back of the one or more adjustable extensions. This may be a particular advantage in in conditions with a low wind speed. Likewise, in conditions with a relatively high wind, the one or more adjustable extensions may be folded to a position with less surface area.

Accordingly, depending on the wind conditions, the wind turbine may be flexible and adapted to ambient conditions to a degree that generates the most optimal wind energy harvest. In some embodiments, a computer means operates in conjunction with the wind turbine and calculates the most efficient configuration of the one or more adjustable extensions.

In some embodiments of the invention, the one or more adjustable extensions (60,61) are adjustable in a way such that the tips (62,63) of said extensions (60,61) are operable to be adjustably positioned relative to a horizontal axis extending centrally from the front area (17) to the back area (19) of the housing (15), such as by means of a fixing member (70).

Hence, also the relative position of the one or more adjustable extensions may be optimized according to optimum harvest of wind energy and/or protected as appropriate with varying positions. In some embodiments, the one or more adjustable extensions may be bend fully backwards and to the other extreme, the one or more adjustable extensions may be positioned so they point in a forward direction, depending on the requirement of the system. In some embodiments, the multiple modular sections (35) are 3D printed. Various advantages are associated with 3D printed modules according to the invention, such as reduced production facilities, more precise module structures that may easier fit each other during stacking of modules on site, better opportunities to use different materials for the modules, cheaper production, etc.

In some embodiments of the invention, the one or more adjustable extensions (60,61) are fixed by means of a spring member (71). This embodiment may be particularly beneficial in conditions where shifting wind speed may cause damage to the wind turbine. By use of spring members, there will be some elasticity in the system for protection purposes. In other embodiments, the member is a shock absorber, or other means.

In some embodiments of the invention, the one or more adjustable extensions (60,61) are curved. Optimal curved configurations may be subject to the design of the one or more adjustable extensions. In some configurations, the one or more adjustable extensions are formed as an aircraft wing, in other configurations they are formed in other configurations that are adapted for optimum wind utilization. However, the one or more adjustable extensions may also be configured without a curved structure.

In some embodiments of the invention, the wind turbine (10) is constructed of multiple modular sections (35) that are 3D printed. Various advantages are associated with 3D printed modules according to the invention, such as reduced production facilities, more precise module structures that may easier fit each other during stacking of modules on site, better opportunities to use different materials for the modules, cheaper production, etc.

It is noted that by “3D printing”, it is intended that the complete module may be 3D printed, but it may also be that only a substantial part of the module is 3D printed. For instance, there may be used additional components of a module that are not 3D printed, just that the main core of structure of the module is 3D printed. In yet other embodiments of this aspect, the tower structure (10) may comprise a releasing member (67) configured to release the compressed air from the one or more pressure vessels (90) to operate the at least one wind blade (50), such as the at least two or three wind blades, during periods of less optimal ambient wind conditions, such as periods of low or very low ambient wind speed.

In yet other embodiments of this aspect, the one or more pressure vessels (90) may provide a supplement of wind to operate the at least one wind blade (50) during periods of low or very low ambient wind speed, thereby shifting the area for capturing and guiding ambient wind in a distance X to positions outside the tower structure (10).

In certain aspects of the invention, there is provided a vertical-axis wind turbine for storage of wind energy, the wind turbine (10) comprising: a housing (15) having a front area (17) operable to receive ambient wind for generation of wind energy, a back area (19) operable to point away from the ambient wind direction, a bottom area (21) adapted to be fastened to a solid support (23), a top area (25) positioned in a certain height from the bottom area (21), and side areas (27,29) with one or more openings (33) operable to expel excess wind from the housing (15), the housing (15) comprising: one or more wind rotors (40) extending substantially from the bottom to the top of the housing (15) having vertical axes relative to the ground and each comprising at least one wind blade (50), such as at least two or three, the one or more wind rotors (40) being operable to receive wind from the front area (17) of the housing (15) and expel excess wind through the side areas (27,29); and at least two wind guiding members (55), such as at least three or four, for each of the one or more wind rotors (40) adapted to capture and guide ambient wind from outer positions within the front area (17) of the housing (15) to each of the one or more wind rotors (40), enabling the one or more wind rotors (40) to rotate with an increased speed and/or invoking increased wind force on the one or more wind rotors (40); and a wind turbine foundation comprising one or more pressure vessels (90) as a solid support (23) for the tower structure (10), the one or more pressure vessels (90) being equipped with fastening means (92) for keeping the tower structure (10) in position during operation.

In certain embodiments of this aspect, the one or more pressure vessels (90) may be adapted to be positioned beneath the ground at least partly in replacement of a concrete foundation for the tower structure (10); the one or more pressure vessels (90) are adapted for containing potential energy generated during periods when excess electrical energy is produced by the tower structure (10) and configured to release energy during periods when inadequate electrical energy is produced by the tower structure (10); and the one or more pressure vessels (90) are communicably coupled to one or more air compressors for storing potential energy generated during periods when excess electrical energy is produced by the tower structure (10).

BRIEF DESCRIPTION OF DRAWINGS

The invention will be understood in greater detail with reference to the following figures that serve to illustrate certain particular embodiments of the invention by way of example and are not intended as limitations of broader aspects of the invention:

Fig. la illustrates the back of a vertical-axis wind turbine composed of multiple modular sections with a foundation comprising pressure vessels.

Fig. lb illustrates the front of a vertical-axis wind turbine composed of multiple modular sections with a foundation comprising pressure vessels. Fig. 2a illustrates the front of a vertical-axis wind turbine composed of multiple modular sections with open housing and adjustable extensions pointing in each side direction.

Fig. 2b illustrates the back of a vertical-axis wind turbine composed of multiple modular sections with open housing and adjustable extensions pointing in each side direction.

Fig. 3 illustrates the front of a vertical-axis wind turbine composed of multiple modular sections with adjustable extensions in various positions and a detailed closeup illustration of a wind rotor behind wind guiding members.

Fig. 4a illustrates a cross-section of a vertical-axis wind turbine with two wind rotors and adjustable extensions on each side of the housing equipped with a supporting member to keep the adjustable extensions in a given position.

Fig. 4b illustrates a cross-section of a vertical-axis wind turbine with two wind rotors and adjustable extensions on each side of the housing without supporting members for the adjustable extensions.

Fig. 4c illustrates a cross-section of a vertical-axis wind turbine with different configurations of adjustable extensions, such as curved extensions and extensions resembling aircraft wings.

Fig. 4d illustrates a cross-section of a vertical-axis wind turbine with adjustable extensions comprise telescopic arrangements, where the arrow illustrates the direction of extending the adjustable extensions.

Fig. 5 illustrates the front of a vertical-axis wind turbine composed of multiple modular sections rotationally fastened to a foundation of pressure vessels. Fig. 6 illustrates a cross-section of a vertical-axis wind turbine with two wind rotors and adjustable extensions on each side of the housing and the wind flow through the housing of the wind turbine proceeding via the back of the adjustable extensions in a distance X outside the tip of the extensions.

Fig. 6a illustrates a cross-section of a vertical-axis wind turbine with two wind rotors and adjustable extensions on each side of the housing and the wind flow through the housing of the wind turbine, and a pressure (p) generated at the front of the extensions relative to the back of the extensions.

Fig. 7 illustrates the back of a cross-section of a vertical-axis wind turbine with two wind rotors and adjustable extensions on each side of the housing and the wind flow through the housing of the wind turbine proceeding via the back of the adjustable extensions in a distance X outside the tip of the extensions.

Fig. 8a-8c illustrate a cross-section of a vertical-axis wind turbine and the wind flow through one side of the housing of the wind turbine proceeding via the back of the adjustable extensions in a distance X outside the tip of the extensions for high, middle, and low wind speeds.

Fig. 9 illustrates a cross-section of a vertical-axis wind turbine and the wind flow through one side of the housing of the wind turbine proceeding via the back of one adjustable extension in a situation where one side of the wind turbine is rotated against the wind direction with only one operating wind rotor.

Fig. 9a-9c illustrate a cross-section of a vertical-axis wind turbine is rotatable around a horizontal axis and the one or more adjustable extensions (60,61) are configured in a way that allows the vertical-axis wind turbine to adjust so that the front area (17) of the housing (15) is automatically pointing toward the ambient wind direction during operation. The circle illustrated in the pressure vessel indicated the balance point in the windmill with respect to adjustment relative to the wind. Fig. 9d illustrates a cross-section of a vertical-axis wind turbine where the adjustable extensions as fixed by means of a spring member. The arrows on the left side indicate the flexibility of the spring member and the arrow on the right side illustrates a gust of wind that may be invoked on the adjustable extension.

Fig. 10 illustrates a cross-section of a vertical-axis wind turbine with two wind rotors and adjustable extensions on each side of the housing equipped with a supporting member to keep the adjustable extensions in a given position, where a central pressure vessel in the housing allows compressed air to operate two wind rotors during a period of low or very low ambient wind speed.

Fig. 10a illustrates a cross-section of a vertical-axis wind turbine with two wind rotors and a pressure vessel (65) that is relatively large. The pressure vessel (65) may be available in different sizes dependent on the needs. In some embodiments, the pressure vessel may also be absent, dependent on the needs.

Fig. Ila illustrates one way of connecting multiple modular sections of a verticalaxis wind turbine.

Fig. 11b illustrates details in one way of connecting multiple modular sections of a vertical-axis wind turbine.

Fig. 12a-12d illustrate one way of stacking multiple modular sections of a verticalaxis wind turbine by means of a sliding arrangement on the back area of each modular section and a crane using the sliding arrangement for elevating each modular section to the desired level of the vertical-axis wind turbine.

Fig. 13a-13d illustrate supporting cables for securing a vertical-axis wind turbine. Fig. 14a illustrates a crane with means for carrying personnel for maintenance of the wind turbine.

Fig. 14b illustrates different positions of the back wind guiding members.

Fig. 15a-15c illustrate a cross-section of a vertical-axis wind turbine where the adjustable extensions are fixed in different positions.

DETAILED DESCRIPTION

Referring now to Fig. la, lb, 2a, 2b, 3, 4a-4d, 5, 7, 9a-9d, 10a and 15a-15c, there is provided a vertical-axis wind turbine comprising a housing (15) having a front area (17) operable to receive ambient wind for generation of wind energy, a back area (19) operable to point away from the ambient wind direction, a bottom area (21) adapted to be fastened to a solid support (23), a top area (25) positioned in a certain height from the bottom area (21), and side areas (27,29) with one or more openings (33) operable to expel excess wind from the housing (15).

Typically, the vertical-axis wind turbine operates along a vertical axis where one or more wind rotors move horizontally around a vertical axis generating energy by rotation. In some embodiments, the vertical axis comprises one or more shafts, and in some embodiments the vertical axis comprises one or more hollow tube structures fixed at certain points to the housing of the wind turbine structure. One single shaft may be provided for one axis, or multiple shafts joined together in various joints may be provided for one axis. The same applies for the one or more hollow tube structures when applied, i.e., a single structure may be provided for each axis or multiple structures may be provided for each axis as needed. Other arrangements would also be available.

In the present context, the intended meaning of “a housing (15) having a front area (17) operable to receive ambient wind for generation of wind energy” refers to an area that at least partly points in the wind direction, such as where the wind direction is substantially perpendicular to the front area or in an angle relative to the front area that allows wind to operate one or more wind rotors of the wind turbine.

Accordingly, when the front area is mentioned to “receive” ambient wind, the intended meaning is that the wind may be entering the housing to one or more wind rotors and particularly excluding a situation where wind is exposed to a front area without being able to operate one or more wind rotors of the wind turbine. In this context, “ambient wind” refers to wind that has not been processed or redirected by any element of the wind turbine. Similarly, “ambient wind direction” refers to the direction of this ambient wind.

In a similar way as the front area may receive ambient wind for generation of energy, a back area (19) is mentioned to be operable to “point away” from the ambient wind direction. Essentially, this means that ambient wind is not directly exposed to the back area under normal conditions, except for periodically shifts in the wind direction or other exceptional situations. Various means may be provided in order to have the front area facing the wind direction and the back area pointing away from the wind direction, which means are known to a person skilled in the art. Sensors may be provided that serve to keep the wind turbine in position by rotation and vary the angles that the front area face to the wind direction. However, in certain configurations the wind turbine will be automatically pointed in the wind direction. As the wind direction is usually not a precise measure and will usually change periodically, even within second or minutes, the position of the front and back area may be readily adjusted in order to maximize the generation of wind energy. Hence, the wind turbine may be rotationally adjustable, for instance by means of a rotational platform at the bottom area of the wind turbine. It is contemplated that a certain change in wind direction may not have a substantial impact on the efficiency of the wind turbine, while a substantial change in wind direction may require the wind turbine to be rotated. Accordingly, the wind turbine may be rotated as required but would not need to be rotated immediately when the wind direction changes.

During operation of the vertical-axis wind turbine, side areas (27,29) with one or more openings (33) may serve to expel excess wind from the housing (15). Wind received by the front area of the wind turbine and used for generating energy by the one or more wind rotors may preferably be expelled through side areas of the housing of the wind turbine.

The side areas may comprise one or more openings, such as one opening, two opening, three openings, etc. If the wind turbine is made of modular sections, there may be one openings in each side of the wind turbine for each section. However, also in this situation, more than one opening may be used. The openings may serve to expel excess wind from the housing of the wind turbine and preferably are used to allocate a certain volume of wind with a certain higher speed than the ambient wind to the back of the wind turbine, thereby shifting the area for capturing and guiding ambient wind to positions outside the tip (62,63) of said extensions (60,61).

Further referring to Fig. la, lb, 2a, 2b, 3, 4a-4d, 5, 7, 9a-9d, 10a and 15a, the housing (15) of the wind turbine comprises one or more wind rotors (40) extending substantially from the bottom to the top of the housing (15) having vertical axes relative to the ground and each comprising at least one wind blade (50), such as at least two or three, the one or more wind rotors (40) being operable to receive wind from the front area (17) of the housing (15) and expel excess wind through the side areas (27,29).

Here, the construction may be configured in various conformations. For instance, the housing may consist of one wind rotor (40), preferably in a central position of the housing, or in a side position of the housing. When wind is received by the front area and passes the wind rotor, this wind may be expelled through only one side opening of the housing or allocated to openings in each side of the housing. As the case may be, it occurs that the wind turbine is more stable if openings in each side of the housing are applied. In a presently more preferable configuration, two wind rotors are applied in order to provide a more stable and wind efficient configuration of the wind turbine. In certain embodiments, more than two wind rotors are applied, such as one central rotor and two additional rotors in each side of the housing of the wind turbine. Even further rotors may be anticipated in some embodiments.

In the present context, when the vertical axes are mentioned to extend substantially from the bottom to the top of the housing (15) relative to the ground, this implies that the each of these one or more wind rotors extend substantially vertically from the bottom to the top of the housing (15) relative to one vertical axis. However, these “one or more wind rotors” may consist of multiple rotors jointed together along the vertical axis. For instance, if the wind turbine is made of modular sections, each modular section may comprise separate wind rotors that when jointed with adjacent rotors on the vertical axis constitute “one rotor”. Similarly, this also applies if “two rotors” are used, where these two rotors extend vertically and substantially from the bottom to the top of the housing (15) by means of two axes.

In some embodiments, the one or more wind rotors may not extend to the bottom area (21) of the housing but may extend to a lower part of the housing, such as when modular sections are applied. Here, one or more generators and one or more gearboxes may be present in the bottom of the housing, whereby the rotor does not extend completely to the bottom area (21). Accordingly, when the one or more wind rotors (40) are mentioned to extend substantially from the bottom to the top of the housing (15), this is to be understood in a relative context also allowing for instance a modular section dedicated to equipment for running the wind turbine in the bottom of the construction.

Further referring to Fig. la, lb, 2a, 2b, 3, 4a-4d, 5, 7, 9a-9d, 10a and 15a-15c, the housing (15) comprises at least two wind guiding members (55), such as at least three or four, for each of the one or more wind rotors (40) adapted to capture and guide ambient wind from outer positions within the front area (17) of the housing (15) to each of the one or more wind rotors (40), enabling the one or more wind rotors (40) to rotate with an increased speed and/or invoking increased wind force on the one or more wind rotors (40).

The expression “wind guiding member” in a broad context is to be understood as a physical barrier that is formed in a way that “captures” the wind for further operation of the one or more wind rotors. After the wind is “captured”, the wind is passively “guided” to the one or wind rotors by means of the physical configuration of the wind guiding members. Typically, the “wind guiding members” (55) are plates, either curved or non-curved, positioned vertically with one of the sides of the plates directed in a certain angle to the wind direction. This allows the wind to be “guided” in the most beneficial manner to the one or more wind rotors. By positioning different wind guiding members in different angles in the front area of the housing, the wind harvested by the one or more wind rotors may be optimized.

Typically, the wind guiding members (55) provide stability to the housing of the wind turbine, for instance when they are joined to the top and bottom wall of modular sections. The front edges of the wind guiding members may be positioned right beneath the front of the housing or may be positioned in a certain distance behind the front of the housing and even extended in a certain distance outside the housing. Preferably, the back edge of the wind guiding members are positioned close to the outer edges of the one or more wind rotors, allowing the wind rotors to rotate properly and preferably allowing most of the wind to target the outer areas of the one or more wind rotors in order to provide optimized momentum of the rotors.

In some embodiments, the wind guiding members may be part of the construction of the housing and not necessarily separate elements of the housing. For instance, the outermost wall of each side of the housing may serve as a wind guiding member in the present context, whereas when a central pressure vessel is applied according to some embodiments, then the outer walls of this vessel may also serve as wind guiding member in the present context.

In essence, when allocating wind guiding members in different angles along the front area of the housing, the ambient wind may be “concentrated” in a smaller area or volume close to the wind rotors, thereby generating a higher wind speed than the ambient wind speed for the wind rotors. At least two wind guiding members may be adequate to generate a higher wind speed. However, more than two wind guiding members would be preferred in order to generate maximum wind speed, but also in order to provide increased stability of the wind turbine construction.

Preferably, at least 3 or 4 wind guiding members are applied, such as 5, 6, 7, 8, 9 or 10 wind guiding members, or even more. These may be applied in vertical rows, or if modular sections are applied these may be scattered vertically throughout the front area of each modular section. Less wind guiding members can generally be applied by using curved wind guiding members but can also be applied by varying the length of the wind guiding members extending from the front area of the housing to the one or more rotors, such as two wind rotors extending from the left or right edges of the front area to a suitable position close to the one or more wind rotors, such as close to the outer portion of the one or more wind rotors.

In some embodiments, the wind guiding members are adjustable. Hence, depending on the ambient wind direction and ambient wind force, the wind guiding members may be adjusted to optimize the “concentrated” wind allocated to the one or more wind rotors. This serves several benefits such as a housing being more responsible to shifts in the wind direction and thereby optimization of the wind energy generation. Also, adjustable wind guiding members may have the result that the wind turbine as such may not need to be rotated to the same degree as if adjustable wind guiding members were not present. In some embodiments, all wind guiding members are adjustable, in other embodiments only one or a few are adjustable. Presently, it is preferred that the wind guiding members are not adjustable but fixed in order to increase the stability of the wind turbine.

Obviously, in order to operate the one or more wind rotors, the wind needs to be allocated to the same side of the one or more wind rotors during operation. In a presently preferred embodiment, when two wind rotors are applied, the wind guiding members are constructed in a way that allows the two wind rotors to rotate in different directions, expelling excessive wind through the side areas. Typically, a preferred construction is that a left wind rotor rotates counter-clockwise, whereas a right wind rotor rotates clockwise. Without being bound by theory it is believed that this configuration gives the most stable construction and maximizes the wind utilization most advantageously.

Generally, when a vertical-axis wind turbine is referenced in the present context and referenced in the figures, it is presently preferred that the wind turbine is symmetrical around a central vertical axis. For instance, in this configuration two wind rotors may be applied symmetrically in each side of the housing of the wind turbine, and wind guiding members may also be distributed symmetrically around a central vertical axis, preferably along with other elements of the housing of the wind turbine.

Symmetry may be beneficial in order to provide balanced force allocation throughout the wind turbine, as well as stability. As another point, symmetry may also provide production benefits, also when the wind turbine is made of modular sections. More importantly, efficiency of the wind turbine may be increased when the housing of the wind turbine is made around a central vertical symmetrical axis, particularly when adjustable extensions (60,61) are provided. Adjustable extensions usually increases the area subject to ambient wind forces considerably, hence balance and stability may be increasingly important as the area increases. Therefore, it is contemplated that symmetry of the structure provides particular advantages.

If modular sections are applied, it may be a benefits that each modular section is identical or substantially identical. Both from a design perspective but more importantly from a production perspective, identical or substantially identical modules may result in a very cost effective wind turbine alternative compared to conventional horizontal-axis wind turbines. Additionally, transportation may be considerable easier, in some cases only requiring standard transportation vehicles to the site of operation.

One of the advantages of the wind turbine according to the invention is that a minimum threshold wind force is not required in order to initiate wind production. While conventional wind turbines may require such a minimum threshold wind force, which in some cases may be relatively high, the instant wind turbine may utilize ambient wind even in low or very low ambient wind conditions. This advantage has an impact on the overall wind production and subsequently efficiency of the wind turbine.

In some embodiments, the wind stored in the pressure vessels may be used to start up the wind turbine in case the ambient wind is not strong enough to start up the wind turbine or in case there is another reason to start up the wind turbine by use of stored energy. For instance, if ambient wind is low or very low, it may be beneficial to utilize the stored wind in the pressure vessels to initiate the system. In some instances, stored wind for starting up the wind turbine may initiate a cumulative utilization of the ambient wind to generate relatively more energy than would be harvested without this initialization. Generally, the materials used for the wind turbine and components would be known by a person skilled in the art of wind turbines and would include a steel or fiberglass construction similar to conventional horizontal-axis wind turbines, or for instance aluminum or wood construction. The materials used for the different elements may differ, for instance the one or more rotors may be produced in a different material than the rest of the construction, etc. Reinforcement of the construction may be applied, particularly with the aim of providing increased stability. Certain critical parts, such as adjustable extensions, may be made of a different material in order to withstand forces on site of operation. Additionally, the construction may be subject to wiring (99) attachment to the ground, or similar stability increasing means, as illustrated in Fig. 13a-13d.

Further referring to Fig. la, lb, 2a, 2b, 3, 4a-4d, 5, 7, 9a-9d, 10a, and 15a-15c, the wind turbine (10) comprises one or more adjustable extensions (60,61) on each side of the housing (15), extending substantially from the bottom to the top of the housing (15), wherein said extensions (60,61) are operable to generate a higher pressure (p) at the front (66) of said extensions (60,61) relative to the back (68) of said extensions (60,61) during operation, thereby generating a pressure difference between the front area (17) and the back area (19) of the housing (15) enabling the one or more wind rotors (40) to rotate with a pressure driven increased speed and/or invoking a pressure driven increased wind force on the one or more wind rotors (40).

In another embodiment, or in addition, the front (66) of said extensions (60,61) is adapted to increase the area for capturing and guiding ambient wind from positions outside the housing (15) to each of the one or more wind rotors (40), and wherein the back (68) of said extensions (60,61) is adapted to allow expelled excess wind from the side areas (27,29) of the housing (15) to proceed in a distance X outside the tip (62,63) of said extensions (60,61), thereby shifting the area for capturing and guiding ambient wind to positions outside the tip (62,63) of said extensions (60,61). In the present context, “adjustable extensions” generally refer to flaps-like “plates” or “wings” provided on each side of the housing of the wind turbine. These extensions provide various benefits, such as establishing a pressure difference between the front and back of the extensions. Also, or in addition, the adjustable extensions may provide an increasing area for capturing and guiding ambient wind from positions outside the housing (15) to each of the one or more wind rotors (40) and shifting the area for capturing and guiding ambient wind to positions outside the tip (62,63) of said extensions (60,61). Various benefits are associated with the adjustable extensions.

The adjustable extensions are typically in the shape of curved plates on each side of the housing as illustrated in the drawings that may be “folded out” upon installation of the wind turbine from a closed position during transportation on the site of operation. In some embodiments, the adjustable extensions are each folded-out to a position on each side of the housing so that they provide a maximum width of the construction (middle position in Fig. 3).

In other embodiments, they are folded out backwards from a horizontal axis of the housing (back position in Fig. 3) or in a forward position from a horizontal axis of the housing (front position in Fig. 3). In yet other embodiments, the adjustable extensions are folded-out independent of each other, such as one being in a closed position, whereas the other are folded-up in a middle-position. Generally, in order to provide the most optimal conditions for capturing and guiding wind to the one or more wind rotors, the adjustable extensions are folded-out to the same position. In this way, ambient wind may be harvested from one common areas constituted by the adjustable extensions. Preferably, ambient wind may not enter in-between the adjustable extensions.

The position of the adjustable extensions mainly depends on the ambient wind direction and ambient wind speed and serves to optimize the wind energy generation. One means of maintaining the adjustable extensions in a proper position may be to partly fix the extensions to an element (70) as illustrated in Fig. 4a. This element may in some embodiments be disconnected to the housing, for instance during transportation, or in some embodiments this element may not be needed depending on the force generated by the ambient wind to the system. In some embodiments, the adjustable extensions are locked in a fixed position, preferably in the same position.

According to the invention, the one or more rotors of the wind turbine may be operated by direct exposure to ambient wind on the rotor blades, the pressure difference generated by means of the one or more extensions according to the invention may establish an even more efficient utilization of the wind energy. Accordingly, the efficiency of energy production is even further improved by the presence of the one or more extensions according to the invention.

With reference to Fig. 6a, it is contemplated that the relative low pressure on the backside of the housing of the wind turbine compared to the higher pressure on front of the housing of the wind turbine provides a synergistic effect in terms of rotation of the one or rotors according to the invention. This is especially pronounced in conditions of low ambient wind speed, where a relatively high pressure difference may be generated between the front and backside of the one or more adjustable extensions, which may provide a synergistic higher utilization of the wind energy.

In some embodiments, the adjustable extensions are intended to cover an increased area in order to capture wind and guide this wind from outside of the housing of the wind turbine to the one or more wind rotors. Particularly, in shallow wind the adjustable extensions may provide very advantageous optimization of wind energy generation. For instance, the wind turbine may be operational in wind conditions where conventional wind turbines may not be operational, such as in wind conditions with low or very low wind speed, or even with zero wind if stored wind is applied. This may address a demand for electricity in periods where traditional windmills or wind turbines cannot operate. Special attention is drawn to the back (68) of said extensions (60,61) that is adapted to allow expelled excess wind from the side areas (27,29) of the housing (15) to proceed in a distance X outside the tip (62,63) of said extensions (60,61), thereby shifting the area for capturing and guiding ambient wind to positions outside the tip (62,63) of said extensions (60,61). This is particularly illustrated in Fig. 6 and Fig. 7.

Referring to Fig. 6 and Fig. 7., it may be seen how the wind flow may proceed with adjustable extensions for a vertical-axis wind turbine. As can be seen in this embodiment, ambient wind is captured and guided by the adjustable extensions to the front of the housing of the wind turbine via wind guiding members to the one or more wind rotors. Upon “concentration” of the wind for operating the wind rotors, the wind rotors rotate with increased speed and/or increased force are subjected to the wind rotors, whereafter the wind is expelled on the back of the adjustable extensions with a wind speed that is higher than ambient wind speed.

According to this embodiment, the wind proceeding along the back of the adjustable extensions may provide several benefits. One of these advantages is that the ambient wind force subject to the front of the adjustable extensions may be somewhat counteracted by the expelled wind proceeding along the back of the adjustable extensions. In some cases, the force on the back of the adjustable extensions substantially counteracts the force invoked on the front of the adjustable extensions or at least a part of the force invoked. This means that a fixing member (70) may be absent or have less impact on the general stability of the system.

Another advantage of this embodiment occurs as the wind proceeds in a distance X outside the tip (62,63) of said extensions (60,61), thereby shifting the area for capturing and guiding ambient wind to positions outside the tip (62,63) of said extensions (60,61). As the wind reaches the tip of the adjustable extensions, the increased wind speed on the back of the adjustable extensions in beneficial embodiments creates a “wind barrier” outside the tip (62,63) of said extensions. As illustrated in Fig. 6 and Fig. 7, the distance that the wind travels outside the tip of said adjustable extensions and thereby the “wind barrier” is indicated with an “X”.

As ambient wind approaches the “wind barrier” in this embodiment, this “wind barrier” may work to capture and guide ambient wind from outside the tip of the adjustable extensions all the way to the one or more rotors on the front side of the adjustable extensions. Without being bound by theory it is contemplated that wind turbulence in some embodiments may substantially increase the efficiency of the “wind barrier” in the present context. For example, when ambient wind meets the expelled wind from the backside of the adjustable extensions having increased speed, turbulence may result in turbulence that results in pressure difference forcing the wind to the one or more wind rotors of the wind turbine. In some instance, wind turbulence generated may even further extend the distance “X” whereby unforeseen synergy is provided for the efficiency of the wind turbine.

These advantageous technical effect of the embodiments in turn increases the wind speed and/or the force invoked on the one or more rotors and thereby serves to generate even more wind energy. A steady state cycle is reached with maximized utilization of ambient wind.

Generally, the distance “X” is dependent on ambient wind conditions. If ambient wind speed is high, then the distance “X” in some embodiments is less than for conditions where ambient wind speed is lower. Also, the distance “X” is dependent on the angle to which the wind turbine is adjusted relative to the wind direction. The advantage is not that profound in conditions of high wind speed as the wind energy received is usually adequate to generate the needed electrical energy. However, in situations with low or very low wind conditions, the impact may be very high, or even in middle wind conditions the impact is high. The general aim of said system is to maximize the area to which ambient wind is subjected and therefore the area for which ambient wind is captured and guided to the one or more wind rotors. Referring now to Fig. 2a, 2b, 3, 4a-4d, 5, 6, 6a, 7, 9, 9a-9d, 10a and 15a-15c, there is provided a vertical-axis wind turbine comprising two vertical axes of wind rotors being positioned in a left and a right side location of the housing (15), preferably relative to a central vertical axis of the housing (15).

This preferable embodiment of a vertical-axis wind turbine may provide the aforementioned symmetry of the wind turbine with the aforementioned benefits, including increasing efficiency of the wind turbine. In some embodiments, however, the two wind rotors are not positioned symmetrically around the vertical axis but one of the wind rotors are positioned without this symmetry. This may have the benefit of providing more efficiency in situations where the front area of the wind turbine is not perpendicular to the wind direction, or in situations where elements in the housing of the wind turbine prevents symmetry.

In some embodiments, the at least two wind guiding members (55), such as the at least three or four, for each of the one or more wind rotors (40) is adapted to capture and guide ambient wind from outer positions within the front area (17) of the housing (15) to an outer portion of the at least one wind blade (50) of each of the one or more wind rotors (40). This is particularly illustrated in Fig. 4a, 4b, 6, and 8a-8c.

Special benefits are provided by directing the wind captured to an outer portion of the at least one wind blade of the wind rotors. Particularly, when the wind is directed to the outer portion of the wind rotors, the momentum of the wind rotors is optimized and thereby energy efficiency of the wind rotors is optimized. It is noted that the wind rotors may comprise a wind brake. Hence, when wind is directed to the wind rotors, the wind rotors may either rotate with increased speed or by using the wind brake, the wind rotors may generate more energy per rotation of the wind rotors.

Combinations may apply depending on the ambient conditions.

Generally, the one or more wind rotors may comprise one or more blades. The special construction of the wind guiding members may allow one wind blade on each wind rotor. The wind funneled through the housing of the wind turbine may generate enough pressure to provide rotation if only one wind blade is present on each wind rotor, thereby forcing the blade around the vertical axis, in turn subjecting the blade to direct exposure to wind guided by the wind guiding members (55) after a certain rotation. However, two wind blades would be more preferred, whereas three wind blades for each wind rotor would be most beneficial although more than 4 wind blades may be present for each wind rotor.

Referring now to Fig. 2a, 2b, 3, 4a-4d, 5, 6, 6a, 7, 9, 9a-9d, 10a and 15a-15c, there is provided a vertical-axis wind turbine wherein the at least two wind guiding members (55), such as at least three or four, for each of the one or more wind rotors (40) are positioned in the housing (15) with different angles relative to the ambient wind direction, and wherein different sides of the at least two wind guiding members (55) for each of the one or more wind rotors (40) point in the ambient wind direction.

The benefit of this construction is that wind may be captured and guided from the entire front area of the housing of the wind turbine, whereby the wind may be more “concentrated” for the one or more wind rotors. Also, change in ambient wind direction may be accommodated in the sense that a certain change in wind direction may result in substantially the same “concentration” of wind for the one or more wind rotors. Given that different sides and angles are applied relative to the wind direction, there would usually be guidance for the wind to reach the one or more wind rotors. This may be further strengthened with multiple wind guiding members.

Typically, the housing of the wind turbine is designed with a curved line front area and/or a curved back areas as illustrated in the drawings, although the housing may also have other designs. This shape increases the function of the wind guiding members being able to capture wind even when the wind direction is substantially changed relative to the front area. If the wind direction changes up to 90 degrees, the front of the housing of the wind turbine may still capture and guide wind to the one or more rotors by means of the shape of the front area. This provides great flexibility of the wind turbine according to this embodiment and utility of ambient wind even in severe conditions with changing wind directions. Also, if wind gusts occur, these may to some extend be absorbed by means of this design of the wind turbine. Additionally, this shape may increase the strength of the construction.

Presently preferred dimensions of the housing of the wind turbine is a width (from a left side area to a right side area) of 5-30 meters, such as 8-25 meters, such as 10-22 meters, such as 12-20 meters, such as 14-18 meters. In some embodiments a width of about 16 meter is preferred in order to utilize a maximum length of transportation vehicles, such as when modular sections are used. In case modular sections are applied, the depth of each modular section may also be adapted to fit for transportation vehicles, such as a depth (from the front area to the back area) about 4.5 meters. Presently preferred dimensions of the housing of the wind turbine may be a depth (from the front area to the back area) of 1-10 meters, such as 2-8 meters, such as 3-6 meters, such as 4-5 meters. However, other dimensions may be applied and would not be a limiting factor of the wind turbine.

Alternative dimensions of the housing of the wind turbine is a width (from a left side area to a right side area) of 0.5-10 meters, such as 0.5-15 meters, such as 0.5-10 meters, such as 0.5-5 meters. Alternative dimensions of the housing of the wind turbine may be a depth (from the front area to the back area) of 0.2-5 meters, such as 0.3-4 meters, such as 0.5-3 meters. However, other dimensions may be applied and would not be a limiting factor of the wind turbine.

If modular sections are applied, the height of each modular section may also be adapted to fit for transportation vehicles, such as a height (from the bottom to top of each modular section) about 4.5 meters. Presently preferred dimensions of each modular section of the housing of the wind turbine may be a height of 1-10 meters, such as 2-8 meters, such as 3-6 meters, such as 4-5 meters. However, also in this case, other dimensions may be applied and would not be a limiting factor of the wind turbine. Referring now to Fig. 2b, 4a, 4b, 5, 6, 7, 8a-8c, 9 and 14b, there is provided a vertical-axis wind turbine wherein the housing (15) comprises one or more back wind guiding members (57), such as adjustable wind guiding members (57), adapted to capture and guide excess wind after passing the one or more wind rotors (40) through the one or more openings (33) of the side areas (27,29) to the back (68) of said extensions (60,61), whereby expelled excess wind is forced and directed to proceed in a distance X outside the tip (62,63) of said extensions (60,61).

For certain wind conditions and certain designs of the wind turbine, it may be advantageous to direct the expelled wind after passing the one or more rotors to the back (68) of said extensions (60,61) in the most efficient way. Hence, by providing back wind guiding members (57) that may guide the wind appropriately in the right direction, the expelled excess wind may be forced and directed more efficiently to proceed in a distance X outside the tip (62,63) of said extensions (60,61) along the back of the adjustable extensions. However, if for instance a curved back area of the housing is applied as illustrated in the drawings, it may not be necessary to further adjust or provide back wind guiding members.

In some embodiments, the back wind guiding members (57) are an integral part of the housing. In some other embodiments, the back wind guiding members (57) are mounted to the housing and may extend in a distance from each side of the housing. In some other embodiments, the back wind guiding members (57) are adjustable. In some other embodiments, the back wind guiding members (57) are adjustable and positioned in parallel with the adjustable extensions (60,61).

The back wind guiding members may be integrated in the design or the back wall of the housing of the wind turbine. In other cases, the back wind guiding members may be configured and designed to provide the adequate direction of the wind along the back of the adjustable extensions. These may be fixed, or the back wind guiding members may be adjustable (Fig. 14b) so that the wind direction may be adjusted according to ambient wind conditions. One or more back wind guiding members may be applied, both if they are fixed in the construction or adjustable, depending on the requirements. What is decisive is that expelled wind proceeds along the back of the adjustable extensions.

Referring to Fig. 6 and Fig. 7., the distance X outside the tip (62,63) of said extensions (60,61) may constitute up to 5 times the distance that the expelled excess wind from the side areas (27,29) of the housing (15) travels over the back (68) of said extensions (60,61), such as up to 4 times the distance, such as up to 3.0 times the distance, such as up to 2.5 times the distance, such as up to 2.0 times the distance, such as up to 1.5 times the distance, such as up to 1.0 times the distance, such as up to 0.6 times the distance, such as up to 0.4 times the distance, such as up to 0.2 times the distance,

The distance X outside the tip (62,63) of said extensions (60,61) may increase with decreasing ambient wind speeds, thereby shifting the area for capturing and guiding ambient wind to positions outside the tip (62,63) of said extensions (60,61) to a higher degree with decreasing ambient wind speeds.

Referring now to Fig. 8a-8c, the distance “X” outside the tip (62,63) of said extensions (60,61) is illustrated as a function of increasing ambient wind speed. In Fig. 8a, ambient wind speed is relatively high, and in this embodiment the distance “X” may be relatively low. Further, in Fig. 8b, ambient wind speed is moderate, and in this embodiment the distance “X” may be moderate. Finally, in Fig. 8c, ambient wind speed is relatively low, and in this embodiment the distance “X” may be higher. Obviously, the situation may depend on various factors, such as the extent to which a wind brake is used for the one or more wind rotors, the angle of the back wind guiding members, etc.

However, it is generally considered that the special technical benefit of the embodiment is more pronounced for low or relatively low wind speeds, where the distance “X” may serve to considerably increase the efficiency of the wind turbine. The special technical benefits may be even more improved if stored wind is expelled to the back of the adjustable extensions during low or very low ambient wind speed according to some embodiments of the invention. In this situation, a surprisingly efficient wind energy generation may be obtained if this stored wind energy is expelled on the back of the adjustable extensions in addition to the processed ambient wind being expelled on the back of the adjustable extensions. The stored wind energy in addition to the processed ambient wind may provide a remarkable synergy in low or very low wind condition where conventional wind turbine cannot operate.

In some embodiments, the stored wind is expelled to the back of the adjustable extensions directly from the pressure vessels in order to benefit from on increased distance “X” outside the tip (62,63) of said extensions (60,61). In some embodiments, the stored wind is expelled to the back of the adjustable extensions via channels or valves from the pressure vessels in order to benefit from on increased distance “X” outside the tip (62,63) of said extensions (60,61). In some embodiments, the stored wind is expelled to the back of the adjustable extensions via the one or more wind rotors from the pressure vessels in order to benefit from on increased distance “X” outside the tip (62,63) of said extensions (60,61). In this embodiment, the stored wind energy will both serve to operate the one or more wind rotors directly and increase the distance “X” which in turn may provide additional ambient air supply for the one or more wind rotors.

Special consideration may apply in high winds or very windy conditions. In this case, as illustrated in Fig. 9, the housing of the wind turbine may be rotated in an angle to the ambient wind direction so that for instance only one wind rotor is operable. During these conditions, the adjustable extensions may be superfluous because the energy generated by the one wind rotor may be sufficient to generate enough energy and even may be enough to store wind energy for later use. The one or more wind rotors may be subject to wind brake as required and may be completely stopped. In some embodiments, as illustrated in the drawings there is provided a vertical-axis wind turbine wherein the wind speed of the expelled excess wind from the side areas (27,29) of the housing (15) is up to 20 times the ambient wind speed, such as up to 15 times the ambient wind speed, such as up to 10 times the ambient wind speed, such as up to 5 times the ambient wind speed, such as up to 3 times the ambient wind speed, thereby establishing a wind barrier in a distance X outside the tip (62,63) of said extensions (60,61). Without being bound by theory it is believed that the level of increased wind speed along the back of the adjustable extensions provides a critical contribution to the benefits of the invention which was not expected by the inventor(s).

Generally, it is contemplated that the method of generating wind energy can be summarized as follows in one aspect of the invention: i) providing a vertical-axis wind turbine (10) with one or more adjustable extensions (60,61) on each side of a housing (15) of the wind turbine (10), extending substantially from the bottom to the top of the housing (15); ii) generating a higher pressure at the front (66) of said extensions (60,61) relative to the back (68) of said extensions (60,61) during operation, thereby generating a pressure difference between the front area (17) and the back area (19) of the housing (15); and iii) enabling the one or more wind rotors (40) to rotate with a pressure driven increased speed and/or invoking a pressure driven increased wind force on the one or more wind rotors (40).

Generally, it is contemplated that the method of generating wind energy can be summarized as follows in one aspect of the invention: i) providing a vertical-axis wind turbine (10), ii) capturing ambient wind from outer positions, iii) guiding the ambient wind to one or more wind rotors (40) of the wind turbine (10), iv) expelling excess wind from the wind turbine (10) with a wind speed higher than ambient wind speed, and v) shifting the area for capturing ambient wind to positions outside the wind turbine (10).

Turning now to a special configuration of the invention, as illustrated in Fig. la, lb, 2a, 2b, 3, 5, and 7, and particularly in Fig. I la, 1 lb, and 12a-12d, there is provided a vertical-axis wind turbine, wherein the wind turbine (10) is constructed of multiple modular sections (35), preferably identical modular sections, stacked on each other in a vertical direction with a bottom and top area (37) adapted to be fastened to an adjacent modular section.

Modular sections may provide several benefits. One of the advantages is that a wind turbine in sections may be transported to sites more efficiently and cost inexpensive compared to conventional wind turbines that usually require transportation equipment that are associated with high costs. Another benefit is that the size of each modular section may be adapted for fitting transportation vehicles of conventional size, thereby addressing cost reductions for transportation. Yet another benefit as can particularly be seen in Fig I la and 1 lb as well as Fig. 12a-12d is that modules may easily be stacked on each other from the ground to the top with less expensive equipment and faster than conventional wind turbines, also on sites with restricted access.

Particularly, as illustrated in the drawings there is provided a vertical-axis wind turbine constructed of modular sections, the wind turbine (10) comprising multiple modular sections (35), preferably identical, each modular section (35) having a front area (17) operable to receive ambient wind for generation of wind energy, a back area (19) operable to point away from the ambient wind direction, a bottom and top area (37) adapted to be fastened to adjacent modular sections (35), and side areas (27,29) with one or more openings (33) operable to expel excess wind from each modular section (35), each modular section (35) comprising one or more wind rotors (40), such as at least two or three, having vertical axes relative to the ground and each comprising at least one wind blade (50), such as at least two or three, the one or more wind rotors (40) being connected and fixed to wind rotors (40) of adjacent modular sections (35), whereby the wind rotors (40) of adjacent modular sections (35) are united and extending substantially from the bottom to the top of the multiple modular sections (35), and each of the one or more wind rotors (40) of each modular section (35) being operable to receive wind from the front area (17) of the modular section (35) and expel excess wind through the side areas (27,29); and at least two wind guiding members (55), such as at least three or four, for each of the one or more wind rotors (40) adapted to capture and guide ambient wind from outer positions within the front area (17) to each of the one or more wind rotors (40), enabling the one or more wind rotors (40) to rotate with an increased speed and/or invoking increased wind force on the one or more wind rotors (40).

Particularly, when modular sections are applied, the bottom and top area (37) of each modular section (35), may be adapted to be fastened to adjacent modular sections (35), comprise a wall member (37) and may be fastened in a manner that does not allow ambient wind to proceed in between connected wall members (37).

More particularly, when modular sections are applied, the bottom and top area (37) of each modular section (35), may be adapted to be fastened to adjacent modular sections (35), and may be at least partly stabilized by the at least two wind guiding members (55), such as the at least three or four wind guiding members.

Even more particularly, when modular sections are applied, the at least two wind guiding members (55), such as the at least three or four wind guiding members, may be positioned perpendicular to the bottom and top area (37) of each modular section (35) adapted to be fastened to adjacent modular sections (35). Importantly, when modular sections are joined together, the one or more rotors are to be connected for each axis so that they may be operable throughout the top to the bottom of the wind turbine. Various means may be used for this purpose, such as a screw joint of the one or more wind rotors (96) on joining means (95). The individual modules may also be fixed to each other, such as fixing the walls (37) of the modular sections to adjacent modules.

Presently, it is preferred that individual modular sections are identical, except for a first module provided in the bottom with equipment, such as one or more gearboxes and generators. While this configuration provides more easy mounting and production benefits, the modular sections may in some other embodiments be individualized for the height they are applied in, or in some instances be different for design purposes. A total of a few modules may be adequate for a functioning wind turbine. However, in preferred embodiments multiple modular sections are stacked on each other to provide a wind turbine structure of a certain height. As would be known by a person skilled in the art, the high of the wind turbine has a substantial impact on the efficiency.

Referring to Fig 12a-12d, there is provided a vertical-axis wind turbine, wherein the wind turbine (10) is constructed of multiple modular sections (35), preferably identical modular sections, each comprising a sliding arrangement (38) on the back area (19) of the housing (15) for stacking the modular sections (35) on each other with a mounting arrangement (39), the wind turbine (10) optionally comprising as the first modular section near the ground a modular section (36) with supporting equipment, such as one or more gearboxes, one or more generators for converting wind energy to electrical energy, and one or more air compressors.

According to this embodiment, the sliding arrangement on back of each modular section makes it possible to lift a crane in the vertical direction, hence building each module on top of each other. This embodiment is presently preferred but an extern crane may also be applied when needed or in support of a crane applied to the sliding arrangement. The sliding arrangement may also be used when modular sections are not applied. The sliding arrangement has the added benefit that maintenance and service of the wind turbine may be easier since a crane may be applied to the sliding arrangement when needed which may be used to lift personnel to the site of maintenance. The modular section may be connected with any fastening means, such as bolts, or the modular sections may be joined by welding.

Referring to Fig I la, the modular sections may be assembled and positioned under installation via certain positioning means (98,99) that may serve to more precisely keep the individual modules in a correct position to each other. In some embodiments, these means (98,99) may also serve as fastening means, such as including bolts.

Referring to Fig 14a, there is provided a vertical-axis wind turbine with a crane mounted to the sliding arrangement (38) where personnel may be lifted to a position on the outside of the wind turbine and thereby may perform maintenance on the outside of the wind turbine.

In some embodiments, the one or more adjustable extensions (60,61) on each side of the housing (15) may be folded to a position where the front (66) of said extensions (60,61) closes the front area (17) of the housing (15). This is particularly useful upon transportation of a wind turbine provided in modular sections, whereby each section with adjustable extensions may be delivered without subsequent attachment of adjustable extensions.

Also, as illustrated in the drawings, provided is a modular section for a multiple modular wind turbine, the modular section (35) comprising one or more wind rotors (40), such as at least two or three, having vertical axes relative to the ground and each comprising at least one wind blade (50), such as at least two or three, each of the one or more wind rotors (40) being operable to receive wind from a front area (17) of the modular section (35) and expel excess wind through side areas (27,29) of the modular section (35); at least two wind guiding members (55), such as at least three or four, for each of the one or more wind rotors (40) adapted to capture and guide ambient wind from outer positions within the front area (17) of the modular section (35) to each of the one or more wind rotors (40), enabling the one or more wind rotors (40) to rotate with an increased speed and/or invoking increased wind force on the one or more wind rotors (40); and one or more adjustable extensions (60,61) on each side of the modular section (35), extending substantially from the bottom to the top of the modular section (35), wherein the front (66) of said extensions (60,61) is adapted to increase the area for capturing and guiding ambient wind from positions outside the modular section (35) to each of the one or more wind rotors (40).

Turning now to a special configuration of the invention, as illustrated in Fig. la, lb, 2b, 4a, 4b, 5, 6, 7, 8a-8c, 9, and 10, there is provided a vertical-axis wind turbine, wherein the housing (15) comprises one or more pressure vessels (66) configured to release compressed air during periods when inadequate electrical energy is produced, the compressed air being released from the one or more pressure vessels (65) via a releasing member (67) and applied to operate the one or more wind rotors (40).

Particularly, there is provided a wind turbine system for storage of wind energy, the wind turbine system comprising a tower structure (10) having one or more wind rotors (40) with at least one wind blade (50), such as at least two or three wind blades, one or more generators for converting wind energy to electrical energy, optionally one or more gearboxes, one or more air compressors, and one or more pressure vessels (65,90) being adapted for containing potential energy generated during periods when excess electrical energy is produced and configured to release energy during periods when inadequate electrical energy is produced.

Either the one or more pressure vessels (65) may be part of the tower structure (10) of the wind turbine system and configured to release compressed air for operating the one or more generators during periods of less optimal ambient wind conditions, such as periods of low or very low ambient wind speed. In the alternative or in addition, the one or more pressure vessels (65) may be part of the tower structure (10) of the wind turbine system and configured to release compressed air for operating the at least one wind blade (50), such as the at least two or three wind blades, during periods of less optimal ambient wind conditions, such as periods of low or very low ambient wind speed. Further, in the alternative or in addition, the one or more pressure vessels (90) may be separate from the tower structure (10) of the wind turbine system and configured to release compressed air for operating the at least one wind blade (50), such as the at least two or three wind blades, during periods of less optimal ambient wind conditions, such as periods of low or very low ambient wind speed.

Generally, the pressure vessels (65) in the housing may be positioned in a central elongate closed cavity of the housing, either as one large pressure vessel or as multiple smaller pressure vessels. If provided as one large pressure vessel, this may be in a triangular elongate vessel extending centrally throughout the top to the bottom of the wind turbine as illustrated in the drawings.

Alternatively, if the wind turbine is made up of modular sections, this triangular pressure vessel may be closed sectional wise so that each modular section provides a triangular pressure vessel, preferably interconnected by joints allowing air to be releasably controlled. Another option is that the pressure vessels (65) are provided as cylindrical, smaller pressure vessels in the housing, also interconnected by joints allowing air to be releasably controlled.

Typically, when the one or more pressure vessels (65) are part of the tower structure (10) of the wind turbine system, they are positioned in a central location relative to a central vertical axis of the tower structure (10), preferably the tower structure comprising multiple pressure vessels (65) along the central vertical axis of the tower structure (10). When the one or more pressure vessels (65) are part of the tower structure (10) of the wind turbine system, they may preferably be positioned in multiple modular sections (35) stacked on each other in a vertical direction of the tower structure (10).

The illustrated pressure vessels (65,90) may be communicably coupled to each other and communicably coupled to the one or more air compressors for storing potential energy generated during periods when excess electrical energy is produced by the one or more generators.

The concept is that the wind turbine during operation may accumulate compressed air that may be released during less preferred conditions and released from the one or more pressure vessels (65) via a releasing member (67) and applied to operate the one or more wind rotors (40). Various means may be provided, such as nozzles (67) allowing compressed air through an inlet (68) through an outlet (69) to operate the one or more wind rotors. In this case, the released air may advantageously be directed towards the one or more wind rotors in order to generate electrical energy by rotating the one or more wind rotors. Alternatively, the compressed air may be directed to other means for operating the generation and thereby producing electrical energy.

Common to the alternatives listed, the one or more pressure vessels (65,90) are suitably communicably coupled to the one or more air compressors for storing potential energy generated during periods when excess electrical energy is produced by the one or more generators.

Suitable pressure vessels may have a working pressure of 5 bars or more, such as 10 bars or more, such as 20 bars or more, such as 50 bars or more.

Additionally, the one or more pressure vessels (65,90) may have a capacity of 10.000 liters or more, such as 50.000 liters or more, such as 100.000 liters or more, such as 200.000 liters or more, such as 250.000 liters or more, such as 300.000 liters or more. Generally, the one or more wind rotors are connected to a gearbox, preferably in a bottom modular section of the wind turbine. Here, the rotation of the one or more wind rotors is exchanged and further connected to one or more generators for providing electrical energy. A gearbox may be avoided in some instances. By storing wind energy in pressure vessels, the wind rotors may operate the generators even in conditions without any wind. If compressed air is provided, the wind turbines may be operated for hours or even days without wind.

The size of the gearbox or gearboxes according to the invention may generally be less compared to gearboxes of conventional horizontal-axis wind turbines. While conventional horizontal-axis wind turbines may require of a 100 times exchange, such as with a rotation of 15 rpm, it may be adequate with less than 10 times exchange according to the invention may, such as with a rotation of 150 rpm. In some embodiments, the size of the gearbox or gearboxes according to the invention may be 5-30 times less compared to gearboxes of conventional horizontal-axis wind turbines, such as 10-20 times less.

Additionally, compressed air may be utilized for operating the one or more wind rotors during periods of very low or low wind. Here, as aforementioned, the area for capturing wind from outside the tip of the adjustable extensions may be increased and subsequently it is possible to utilize compressed air for further operating the one or more wind rotors by extending the area for capturing and guiding wind to the one or more wind rotors by a distance “X”. This embodiment is particularly preferred and beneficial since very low or low wind usually means that conventional wind turbines cannot operate.

It is contemplated that in certain embodiments, the pressure vessels are located outside the housing of the wind turbine, such as in external positions or in a foundation of the wind turbine. In these cases, the mechanisms of allocating compressed air to the one or wind rotors or directly via converting means to the one or more gearboxes and/or one or more generators of the wind turbine may be the same as in the case where pressure vessels are provided in the housing of the wind turbine. However, certain advantages are provided by having the pressure vessels in the housing, such in certain sites where it is not possible to have external vessels or pressure vessels in a foundation.

In an embodiment of the invention as illustrated in the drawings, the tower structure (10) comprises a housing (15) having a front area (17) operable to receive ambient wind for generation of wind energy, a back area (19) operable to point away from the ambient wind direction, a bottom area (21) adapted to be fastened to a solid support (23), a top area (25) positioned in a certain height from the bottom area (21), and side areas (27,29) with one or more openings (33) operable to expel excess wind from the housing (15), the housing (15) comprising one or more wind rotors (40) extending substantially from the bottom to the top of the housing (15) having vertical axes relative to the ground and each comprising at least one wind blade (50), such as at least two or three, the one or more wind rotors (40) being operable to receive wind from the front area (17) of the housing (15) and expel excess wind through the side areas (27,29); at least two wind guiding members (55), such as at least three or four, for each of the one or more wind rotors (40) adapted to capture and guide ambient wind from outer positions within the front area (17) of the housing (15) to each of the one or more wind rotors (40), enabling the one or more wind rotors (40) to rotate with an increased speed and/or invoking increased wind force on the one or more wind rotors (40); and the one or more pressure vessels (65) that are part of the tower structure (10) of the wind turbine system.

In this and previous embodiments, the one or more pressure vessels (65,90) may provide a supplement of wind to operate the at least one wind blade (50), such as the at least two or three wind blades, during periods of low or very low ambient wind speed, thereby shifting the area for capturing and guiding ambient wind in a distance X to positions outside the tower structure (10). Additionally, as illustrated in the drawings, the tower structure (10) comprises a housing (15) having a front area (17) operable to receive ambient wind for generation of wind energy, a back area (19) operable to point away from the ambient wind direction, a bottom area (21) adapted to be fastened to a solid support (23), a top area (25) positioned in a certain height from the bottom area (21), and side areas (27,29) with one or more openings (33) operable to expel excess wind from the housing (15), the housing (15) comprising one or more wind rotors (40) extending substantially from the bottom to the top of the housing (15) having vertical axes relative to the ground and each comprising at least one wind blade (50), such as at least two or three, the one or more wind rotors (40) being operable to receive wind from the front area (17) of the housing (15) and expel excess wind through the side areas (27,29); and at least two wind guiding members (55), such as at least three or four, for each of the one or more wind rotors (40) adapted to capture and guide ambient wind from outer positions within the front area (17) of the housing (15) to each of the one or more wind rotors (40), enabling the one or more wind rotors (40) to rotate with an increased speed and/or invoking increased wind force on the one or more wind rotors (40); and one or more pressure vessels (65) being adapted for containing potential energy generated during periods when excess electrical energy is produced and configured to release energy during periods when inadequate electrical energy is produced.

Turning now to a special configuration of the invention, as illustrated in Fig. la, lb, and particularly in Fig. 5, there is provided a wind turbine (10) having a foundation for keeping the wind turbine (10) in position during operation, the foundation comprising one or more pressure vessels (90) adapted for containing potential energy generated during periods when excess electrical energy is produced and configured to release energy during periods when inadequate electrical energy is produced.

Particularly, there is provided a wind turbine foundation, the wind turbine foundation comprising one or more pressure vessels (90) as a solid support (23) for a wind turbine (10), the one or more pressure vessels (90) being equipped with fastening means (92) for keeping a wind turbine (10) in position during operation, wherein the one or more pressure vessels (90) are adapted to be positioned beneath the ground at least partly in replacement of a concrete foundation for a wind turbine (10); the one or more pressure vessels (90) are adapted for containing potential energy generated during periods when excess electrical energy is produced by a wind turbine (10) and configured to release energy during periods when inadequate electrical energy is produced by a wind turbine (10); and the one or more pressure vessels (90) are communicably coupled to one or more air compressors for storing potential energy generated during periods when excess electrical energy is produced by a wind turbine (10). This embodiment may also be used for horizontal-axis wind turbines.

Importantly, a foundation mainly comprised of pressure vessels may solve various problems of energy storage for conventional wind turbine foundations. This type of foundation may be used for conventional horizontal-axis wind turbines or verticalaxis wind turbines according to the invention. The compressed air may be utilized to operate the one more wind rotors as for pressure vessels located in the housing of a wind turbine or may via converting means be used to operate one or more gearboxes and/or one or more generators. Particularly, in Fig. 5, a foundation is provided with cylindrical pressure vessels in the foundation, preferable using no or a very low amount of supporting concrete. These pressure vessels may work as solid support for the wind turbine. The pressure vessels may also be in another form than a cylindrical vessel, such as squared containers.

In an embodiment of the invention, the foundation comprises means for anchoring the one or more pressure vessels (90) beneath the ground. Additionally, fastening means (92) for keeping the wind turbine (10) in position during operation may be provided, such as rails for allowing the wind turbine (10) to rotate at least partly around an axis during operation.

Also, as mentioned for the pressure vessels when contained in the housing of a wind turbine, the one or more pressure vessels (90) in the foundation may have a working pressure of 5 bars or more, such as 10 bars or more, such as 20 bars or more, such as 50 bars or more. The capacity, as also mentioned for the pressure vessels when contained in the housing of a wind turbine, the one or more pressure vessels (90) in the foundation may have a capacity of 10.000 liters or more, such as 50.000 liters or more, such as 100.000 liters or more, such as 200.000 liters or more, such as 250.000 liters or more, such as 300.000 liters or more.

According to embodiments of the invention, the foundation may comprise multiple pressure vessels (90) communicably coupled to each other and communicably coupled to one or more air compressors for storing potential energy generated during periods when excess electrical energy is produced by the wind turbine (10).

In an embodiment of the invention, the wind turbine system for storage of wind energy, the wind turbine system comprising a tower structure (10) having one or more wind rotors (40) with at least one wind blade (50), such as at least two or three wind blades, one or more generators for converting wind energy to electrical energy, optionally one or more gearboxes, one or more air compressors, and a wind turbine foundation comprising one or more pressure vessels (90) as a solid support (23) for the tower structure (10), the one or more pressure vessels (90) being equipped with fastening means (92) for keeping the tower structure (10) in position during operation, wherein the one or more pressure vessels (90) are adapted to be positioned beneath the ground at least partly in replacement of a concrete foundation for the tower structure (10); the one or more pressure vessels (90) are adapted for containing potential energy generated during periods when excess electrical energy is produced by the tower structure (10) and configured to release energy during periods when inadequate electrical energy is produced by the tower structure (10); and the one or more pressure vessels (90) are communicably coupled to one or more air compressors for storing potential energy generated during periods when excess electrical energy is produced by the tower structure (10).

Additionally, in an embodiment of the invention as illustrated in the drawings, there is provided a vertical-axis wind turbine for storage of wind energy, the wind turbine (10) comprising a housing (15) having a front area (17) operable to receive ambient wind for generation of wind energy, a back area (19) operable to point away from the ambient wind direction, a bottom area (21) adapted to be fastened to a solid support (23), a top area (25) positioned in a certain height from the bottom area (21), and side areas (27,29) with one or more openings (33) operable to expel excess wind from the housing (15), the housing (15) comprising one or more wind rotors (40) extending substantially from the bottom to the top of the housing (15) having vertical axes relative to the ground and each comprising at least one wind blade (50), such as at least two or three, the one or more wind rotors (40) being operable to receive wind from the front area (17) of the housing (15) and expel excess wind through the side areas (27,29); and at least two wind guiding members (55), such as at least three or four, for each of the one or more wind rotors (40) adapted to capture and guide ambient wind from outer positions within the front area (17) of the housing (15) to each of the one or more wind rotors (40), enabling the one or more wind rotors (40) to rotate with an increased speed and/or invoking increased wind force on the one or more wind rotors (40); and a wind turbine foundation comprising one or more pressure vessels (90) as a solid support (23) for the tower structure (10), the one or more pressure vessels (90) being equipped with fastening means (92) for keeping the tower structure (10) in position during operation.

In this embodiment as illustrated in the drawings, the one or more pressure vessels (90) may be adapted to be positioned beneath the ground at least partly in replacement of a concrete foundation for the tower structure (10); the one or more pressure vessels (90) may be adapted for containing potential energy generated during periods when excess electrical energy is produced by the tower structure (10) and configured to release energy during periods when inadequate electrical energy is produced by the tower structure (10); and the one or more pressure vessels (90) may be communicably coupled to one or more air compressors for storing potential energy generated during periods when excess electrical energy is produced by the tower structure (10).

Claims

1. A wind turbine foundation, the wind turbine foundation comprising: one or more pressure vessels (90) as a solid support (23) for a wind turbine (10), the one or more pressure vessels (90) being equipped with fastening means (92) for keeping a wind turbine (10) in position during operation, wherein the one or more pressure vessels (90) are adapted to be positioned beneath the ground at least partly in replacement of a concrete foundation for a wind turbine (10); the one or more pressure vessels (90) are adapted for containing potential energy generated during periods when excess electrical energy is produced by a wind turbine (10) and configured to release energy during periods when inadequate electrical energy is produced by a wind turbine (10); and the one or more pressure vessels (90) are communicably coupled to one or more air compressors for storing potential energy generated during periods when excess electrical energy is produced by a wind turbine (10).

2. The wind turbine foundation according to claim 1, wherein the one or more pressure vessels (90) comprise multiple pressure vessels (90).

3. The wind turbine foundation according to any one of the preceding claims, wherein the foundation comprises means for anchoring the one or more pressure vessels (90) beneath the ground.

4. The wind turbine foundation according to any one of the preceding claims, wherein the fastening means (92) for keeping a wind turbine (10) in position during operation comprise rails for allowing the wind turbine (10) to rotate at least partly around an axis during operation.

5. The wind turbine foundation according to any one of the preceding claims, wherein the one or more pressure vessels (90) have a working pressure of 5 bars or more, such as 10 bars or more, such as 20 bars or more, such as 50 bars or more.

6. The wind turbine foundation according to any one of the preceding claims, wherein the one or more pressure vessels (90) have a capacity of 10.000 liters or more, such as 50.000 liters or more, such as 100.000 liters or more, such as 200.000 liters or more, such as 250.000 liters or more, such as 300.000 liters or more.

7. The wind turbine foundation according to any one of the preceding claims, wherein the foundation comprises multiple pressure vessels (90) communicably coupled to each other and communicably coupled to one or more air compressors for storing potential energy generated during periods when excess electrical energy is produced by the wind turbine (10).

8. A wind turbine system for storage of wind energy, the wind turbine system comprising: a tower structure (10) having one or more wind rotors (40) with at least one wind blade (50), such as at least two or three wind blades, one or more generators for converting wind energy to electrical energy, optionally one or more gearboxes, one or more air compressors, and a wind turbine foundation comprising one or more pressure vessels (90) as a solid support (23) for the tower structure (10), the one or more pressure vessels (90) being equipped with fastening means (92) for keeping the tower structure (10) in position during operation, wherein the one or more pressure vessels (90) are adapted to be positioned beneath the ground at least partly in replacement of a concrete foundation for the tower structure (10); the one or more pressure vessels (90) are adapted for containing potential energy generated during periods when excess electrical energy is produced by the tower structure (10) and configured to release energy during periods when inadequate electrical energy is produced by the tower structure (10); and the one or more pressure vessels (90) are communicably coupled to one or more air compressors for storing potential energy generated during periods when excess electrical energy is produced by the tower structure (10).

9. The wind turbine system according to claim 8, wherein the tower structure (10) comprises: a housing (15) having a front area (17) operable to receive ambient wind for generation of wind energy, a back area (19) operable to point away from the ambient wind direction, a bottom area (21) adapted to be fastened to a solid support (23), a top area (25) positioned in a certain height from the bottom area (21), and side areas (27,29) with one or more openings (33) operable to expel excess wind from the housing (15), the housing (15) comprising: one or more wind rotors (40) extending substantially from the bottom to the top of the housing (15) having vertical axes relative to the ground and each comprising at least one wind blade (50), such as at least two or three, the one or more wind rotors (40) being operable to receive wind from the front area (17) of the housing (15) and expel excess wind through the side areas (27,29); and at least two wind guiding members (55), such as at least three or four, for each of the one or more wind rotors (40) adapted to capture and guide ambient wind from outer positions within the front area (17) of the housing (15) to each of the one or more wind rotors (40), enabling the one or more wind rotors (40) to rotate with an increased speed and/or invoking increased wind force on the one or more wind rotors (40).

10. The wind turbine system according to any one of claim 8-9, wherein the tower structure (10) comprises: one or more adjustable extensions (60,61) on each side of the housing (15), extending substantially from the bottom to the top of the housing (15), wherein the front (66) of said extensions (60,61) is adapted to increase the area for capturing and guiding ambient wind from positions outside the housing

(15) to each of the one or more wind rotors (40), and wherein the back (68) of said extensions (60,61) is adapted to allow expelled excess wind from the side areas (27,29) of the housing (15) to proceed in a distance X outside the tip (62,63) of said extensions (60,61), thereby shifting the area for capturing and guiding ambient wind to positions outside the tip (62,63) of said extensions (60,61).

11. The wind turbine system according to any one of claims 8-10, wherein the housing (15) comprises one or more back wind guiding members (57), such as adjustable wind guiding members (57), adapted to capture and guide excess wind after passing the one or more wind rotors (40) through the one or more openings (33) of the side areas (27,29) to the back (68) of said extensions (60,61), whereby expelled excess wind is forced and directed to proceed in a distance X outside the tip (62,63) of said extensions (60,61).

12. The wind turbine system according to any one of claims 8-11, wherein the tower structure (10) comprises one or more adjustable extensions (60,61) on each side of the housing (15), extending substantially from the bottom to the top of the housing (15), wherein said extensions (60,61) are operable to generate a higher pressure at the front (66) of said extensions (60,61) relative to the back (68) of said extensions (60,61) during operation, thereby generating a pressure difference between the front area (17) and the back area (19) of the housing (15) enabling the one or more wind rotors (40) to rotate with a pressure driven increased speed and/or invoking a pressure driven increased wind force on the one or more wind rotors (40).

13. The wind turbine system according to any one of claims 8-12, wherein the tower structure (10) comprises a releasing member (67) configured to release the compressed air from the one or more pressure vessels (90) to operate the at least one wind blade (50), such as the at least two or three wind blades, during periods of less optimal ambient wind conditions, such as periods of low or very low ambient wind speed.

14. The wind turbine system according to any one of claim 8-13, wherein the one or more pressure vessels (90) provide a supplement of wind to operate the at least one wind blade (50) during periods of low or very low ambient wind speed, thereby shifting the area for capturing and guiding ambient wind in a distance X to positions outside the tower structure (10).

15. The wind turbine system according to any one of claim 8-14, wherein the wind turbine foundation is as defined in any one of claims 1-7.

16. A vertical-axis wind turbine for storage of wind energy, the wind turbine (10) comprising: a housing (15) having a front area (17) operable to receive ambient wind for generation of wind energy, a back area (19) operable to point away from the ambient wind direction, a bottom area (21) adapted to be fastened to a solid support (23), a top area (25) positioned in a certain height from the bottom area (21), and side areas (27,29) with one or more openings (33) operable to expel excess wind from the housing (15), the housing (15) comprising: one or more wind rotors (40) extending substantially from the bottom to the top of the housing (15) having vertical axes relative to the ground and each comprising at least one wind blade (50), such as at least two or three, the one or more wind rotors (40) being operable to receive wind from the front area (17) of the housing (15) and expel excess wind through the side areas (27,29); and at least two wind guiding members (55), such as at least three or four, for each of the one or more wind rotors (40) adapted to capture and guide ambient wind from outer positions within the front area (17) of the housing (15) to each of the one or more wind rotors (40), enabling the one or more wind rotors (40) to rotate with an increased speed and/or invoking increased wind force on the one or more wind rotors (40); and a wind turbine foundation comprising one or more pressure vessels (90) as a solid support (23) for the tower structure (10), the one or more pressure vessels (90) being equipped with fastening means (92) for keeping the tower structure (10) in position during operation.

17. The vertical-axis wind turbine according to claim 16, wherein the one or more pressure vessels (90) are adapted to be positioned beneath the ground at least partly in replacement of a concrete foundation for the tower structure (10); the one or more pressure vessels (90) are adapted for containing potential energy generated during periods when excess electrical energy is produced by the tower structure (10) and configured to release energy during periods when inadequate electrical energy is produced by the tower structure (10); and the one or more pressure vessels (90) are communicably coupled to one or more air compressors for storing potential energy generated during periods when excess electrical energy is produced by the tower structure (10).

18. The vertical-axis wind turbine according to any one of claims 16-17, wherein the wind turbine foundation is as defined in any one of claims 1-7.