WO2010148168A1

WO2010148168A1 - System for generating electrical energy using wind power

Info

Publication number: WO2010148168A1
Application number: PCT/US2010/038947
Authority: WO
Inventors: Jonathan C. Ricker
Original assignee: Ricker Jonathan C
Priority date: 2009-06-20
Filing date: 2010-06-17
Publication date: 2010-12-23

Abstract

A system for generating electrical energy using wind power. The system includes an entrance wind augmenter that is a fixed structure supported above the ground that defines an inlet opening (14, 14a) defining an inlet area, an outlet opening defining an outlet area that is substantially smaller than the inlet area, and a plurality of fully or partially closed side walls (7, 16), at least two such side walls (7, 16) being angled from the horizontal so as to create an inwardly-tapered funnel. There is an electricity generation system defined by a fixed structure supported above the ground that supports a number of generating arrays (90) located downstream of the outlet opening (51) of the entrance wind augmenter (12). Each array (90) carries a number of wind turbines (92-95) mounted on a rotatable shaft (98), and an electrical generator (100) having a rotor that is turned by the shaft (98).

Description

SYSTEM FOR GENERATING ELECTRICAL ENERGY USING WIND POWER

FIELD OF THE INVENTION

The invention relates to a system for generating electrical energy using wind power. BACKGROUND OF THE INVENTION

Wind turbines utilize rotors to convert wind energy into mechanical energy, which can then be used to drive an electrical generator. The two primary types of wind turbines are classified by the axis of rotation of the rotor. Horizontal-axis wind turbines (HAWT) typically rotate about a horizontal axis, generally parallel to the ground, spinning in a propeller-type motion. Vertical-axis wind turbines (VAWT) typically rotate about a vertical axis, generally perpendicular to the ground, spinning as a cylinder-type shape in a circle.

As is known in the art, vertical-axis wind turbines offer a number of advantages over horizontal-axis wind turbines. In a HAWT, the rotor and electrical generator must be located at the top of a tower. With a VAWT, however, the electrical generator may be located on the ground for easier maintenance. This arrangement also eliminates the need for the tower to support the generator. HAWTs must be directed into the wind, which requires additional, often expensive, orienting equipment. A VAWT, however, accepts wind from all directions.

On the other hand, because the VAWTs are often-installed on the ground or a roof, rather than on a tower, the lower wind speed at these altitudes results in less available wind energy. In addition, the air flow near the ground may be more turbulent than the air flow at the top of a tower. The vibration caused by the turbulence may result in noise, mechanical wear and tear, and long-term structural problems. When mounted on a tower, conventional VAWTs typically require guy wires to hold the upper bearings in place. This configuration, however, places stress on the lower bearings on which the rotor typically rests, in part because the guy wires increase the downward thrust on the lower bearings when the wind gusts.

Conventional turbines of either type often employ large rotors to generate sufficient electricity. Unfortunately, larger rotors tend to be more expensive to manufacture because of the increased structural requirements, as the stress on the rotors increases dramatically as the diameter of the rotor increases. Conventional turbines also often employ large blades to increase the impact area on the blades in an effort to capture more wind energy. Conversely, the use of large blades that have not been properly designed and manufactured can create structural stress and fatigue problems in the gearbox, the tower, and the generator.

One well-known type of VAWT is the Darrieus wind turbine, described in U.S. Patent No. 1,835,018. The Darrieus turbine is said to resemble an "eggbeater," in that it has curved blades that are connected to the top and bottom of the vertical rotor. The blades have a troposkein shape, which is similar to the shape that a rope would take when the rope is spun around an axis. The troposkein shape minimizes stresses due to centrifugal forces. Prior art VAWTs with Darrieus-type blades are disclosed in U.S. Patent No. 5,499,904, "Vertical Axis Wind Turbine with Pultruded Blades," and U.S. Patent No. 4,449,053, "Vertical Axis Wind Turbine."

The size and strength of the blades in a Darrieus-type wind turbine are limited by the choice of material. For example, blades made of extruded aluminum are limited in length because of the limits of the extrusion process. As a result, large aluminum blades are typically constructed in pieces and assembled on site, but the resulting pieced-together blade does not form a true troposkein shape. Aluminum extrusion is also expensive. Pultruded fiberglass composite blades have been suggested because of the lower manufacturing cost and the capacity for creating long sections with a consistent cross-section. Unfortunately, however, the strength of the pultruded fiberglass blades is limited because the blades must be bent into a troposkein shape prior to installation.

Another well-known type of VAWT is the Savonius wind turbine. The Savonius turbine consists of two or three scoops. A two-scoop Savonius VAWT is said to resemble an "S" in cross-section. Because of their simple shape, Savonius turbines tend to be more reliable and inexpensive to manufacture than Darrieus turbines.

An alternative to conventional turbines is disclosed in U.S. Patent No. 6,864,597, "Multiaxis Turbine," incorporated by reference herein in its entirety. The Mulitaxis Turbine reduces costs by employing small blades, where each blade has a simple design that eliminates twist and taper. Multiple small blades are located on each vertical axis, and multiple vertical axes are arranged in a box-like tower structure of vertical elongated structural members connected by horizontal structural members.

While the Multiaxis Turbine provides many advantages over the prior art, as described in detail in the patent disclosure, there is a need in the art to further reduce the costs of manufacturing and maintaining wind turbines, to significantly lessen the cost per kilowatt hour of electricity produced.

SUMMARY OF THE INVENTION

The wind turbine system of the present invention incorporates one or more rows of wind turbines mounted within a box-like tower structure. The tower structure is constructed of vertical and horizontal structural members. The tower structure may optionally include a roof.

The turbines are mounted in rows on rotor shafts, and the shafts are coupled to the tower structure. The rows of the (preferably vertical-axis type) wind turbines may be mounted vertically or horizontally. The blades of the vertical-axis wind turbines are preferably Savonius- type blades.

The wind turbine system may optionally include a front augmenter and a rear diffuser to increase the wind velocity through the turbines, and as a result, increase the amount of energy generated by the turbines. The front augmenter is positioned in front of the turbines and captures and funnels the wind stream into the turbines. The rear diffuser is positioned behind the turbines and functions to create a pulling action. The augmenter and diffuser may optionally include side and/or top dump panels that open and close as needed to minimize damage to the turbines during wind gusts.

The wind turbine system may optionally include a furling system. The furling system includes one or more panels that open or close automatically to block excessive wind and prevent damage to the turbines and other parts of the system.

The wind turbine system may optionally include a wind diverter or blade blocker, which splits the wind stream as it enters the turbine blade area, feeding a portion of the wind stream into the front of the blade and thereby increasing the volume of wind that impacts the blade, and diverting another portion of the wind stream away from the back of the blade, reducing or eliminating the drag resistance that reduces the turbine's productivity.

The wind turbine system may optionally include an air straightener to reduce air turbulence at the turbine blades. The air straightener employs an open lattice-like structure similar to that of a honeycomb.

This invention features a system for generating electrical energy using wind power, comprising an entrance wind augmenter comprising a fixed structure supported above the ground that defines an inlet opening defining an inlet area, an outlet opening defining an outlet area that is substantially smaller than the inlet area, and a plurality of fully or partially closed side walls, at least two such side walls being angled from the horizontal so as to create an inwardly-tapered funnel and an electricity generation system comprising a fixed structure supported above the ground that supports a plurality of generating arrays located proximate the outlet opening of the entrance wind augmenter, each array comprising a plurality of wind turbines mounted on a rotatable shaft, and an electrical generator having a rotor that is turned by the shaft. The shafts may be horizontal, and the turbines may be Savonius-type turbines that define a generally cylindrical volume in which they rotate.

The entrance wind augmenter may define one or more selectively opened panels along one or more sides, to provide a path for wind to escape the augmenter should its force be too great. One or more of the angled walls of the entrance wind augmenter may lie at an angle of about 22 degrees from the horizontal. The system may further comprise an exit wind diffuser comprising a fixed structure supported above the ground that defines an inlet opening defining an inlet area, an outlet opening defining an outlet area that is substantially larger than the inlet area, and a plurality of fully or partially closed side walls, at least two such side walls being angled from the horizontal so as to create an outwardly-tapered funnel. The exit wind diffuser may define one or more selectively opened panels along one or more sides, to provide a path for wind to escape the diffuser should its force be too great. One or more of the angled walls of the exit wind diffuser may lie at an angle of about 22 degrees from the horizontal.

The system may further comprise a wind diverter constructed and arranged so as to divert wind toward the entrances into the wind turbines and away from areas in which it counteracts turbine rotation. The system may further comprise a furling system that selectively blocks wind from reaching the turbines. The furling system may comprise a movable partition located between the outlet opening of the entrance wind augmenter and the turbines; the partition may be a flat structural member. The furling system may further comprise a motor to move the structural member up and down, and a controller that controls the motor based on the output of the generator.

This invention also features a system for generating electrical energy using wind power, comprising an entrance wind augmenter comprising a fixed structure supported above the ground that defines an inlet opening defining an inlet area, an outlet opening defining an outlet area that is substantially smaller than the inlet area, and a plurality of fully or partially closed side walls, at least two such side walls being angled from the horizontal so as to create an inwardly-tapered funnel, in which one or more of the angled walls of the entrance wind augmenter lie at an angle of about 22 degrees from the horizontal, an electricity generation system comprising a fixed structure supported above the ground that supports a plurality of generating arrays located proximate the outlet opening of the entrance wind augmenter, each array comprising a plurality of Savonius-type wind turbines that define a generally cylindrical volume in which they rotate, the turbines mounted on a rotatable horizontal shaft, and an electrical generator having a rotor that is turned by the shaft, an exit wind diffuser comprising a fixed structure supported above the ground that defines an inlet opening defining an inlet area, an outlet opening defining an outlet area that is substantially larger than the inlet area, and a plurality of fully or partially closed side walls, at least two such side walls being angled from the horizontal so as to create an outwardly- tapered funnel, in which one or more of the angled walls of the exit wind diffuser lie at an angle of about 22 degrees from the horizontal, a wind diverter constructed and arranged so as to divert wind toward the entrances into the wind turbines and away from areas in which it counteracts turbine rotation and a furling system that selectively blocks wind from reaching the turbines, the furling system comprising a movable partition located between the outlet opening of the entrance wind augmenter and the turbines, a motor to move the partition up and down and a controller that controls the motor based on the output of the generator.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects, features and advantages will occur to those skilled in the art from the following description of certain preferred embodiments of the invention, along with the accompanying drawings, in which:

Figure IA is a simplified schematic side view and figure IB a simplified schematic top view of a view of an embodiment of the inventive system;

Figure 2 is a side view of another embodiment of the inventive system;

Figure 3 is a top view of the system of figure 2;

Figure 4 is a partial, disassembled view of one version of the top panels for the system of figures 2 and 3;

Figure 5 is a front view of an embodiment of an electricity generation system for the system of the invention;

Figure 6 is a front view of the entrance to a system of the invention;

Figure 7 is a top view of a horizontal generating array for an electricity generation system for the system of the invention;

Figure 8A is a side cross-sectional view and figure 8B a perspective view of a turbine for the system of the invention;

Figure 9A is a side view of a furling system construction for the system of the invention;

Figure 9B is a top view of the furling system construction of figure 9A;

Figure 9C is a front view of the partition or wind-blocking member for the furling system of figure 9A; and

Figure 9D shows the frame of the partition of figure 9C.

DESCRIPTION OF PREFERRED EMBODIMENTS

Embodiments of systems according to the invention are shown in the drawings. System 10 is shown in Figures IA and IB. System 10 comprises a power-generation section 18 that carries one or more turbines 32 that in this case rotate about horizontal axis 34. The turbines are connected to one or more generators in a manner known in the art so as to generate electricity from the wind. Entrance section 12 (termed an "augmenter" in certain cases herein) captures wind travelling in the general direction of arrow I entering its inlet opening 14 and funnels this wind into power generation section 18, where the wind passes over turbines 32. Entrance section 12 is oriented into the prevailing wind direction. Entrance section 12 comprises upper wall or roof 16 and lower wall 7 that serve to confine the air and direct it toward the turbines. Diffuser 20 may be included on the exit or outlet side of system 10 to direct wind out of the device in the direction of arrow O through exit opening 22. The structure comprising system 10 is held above ground G by vertical supports such as supports 11 and 13.

Augmenter 12 is a fixed structure that acts to capture wind and funnel it toward and into the turbines. Augmenter 12 acts to increase the speed of the airflow and thus increase the amount of electricity generated. Exit diffuser 20 is also a fixed structure that can be essentially identical to augmenter 12 but turned the other way, with a narrow entrance and larger exit. It acts to create a reduced pressure at the outlet of the turbines, thus creating a strong pulling action through the turbine blades which can increase the wind speed and thus the amount of power generated.

Preferably, the flared upper and lower walls of augmenter 12 are fully closed, but they may be partially closed. The walls may lie at an angle of approximately 22 degrees from the horizontal to define a flared wedge-shaped or inwardly-tapered wind funnel or section that spans an angle of approximately 44 degrees. This angle could be larger or smaller. A smaller angle would help accomplish a more laminar flow at the turbines, but to define the same opening area that augmenter would have to be longer. This would increase the footprint of the system as well as its expense. The angle, the augmenter inlet to outlet area ratio and the size and cost of the augmenter are thus competing design considerations. The left and right sides of augmenter 12 are preferably also fully closed (but may be partially closed) and can be vertical (as shown in figure IB), or can themselves be flared outward like the upper and lower walls (as shown in figure 3). In one example, the ratio of the area of the inlet of augmenter 12 to the outlet of augmenter 12 (where the turbines are located) is approximately 6:1. The angle and this ratio have been found to be effective to increase the wind speed by up to and even over 100%, leading to the 3 -fold increase in power generation as compared to the same turbines used without augmenter 12.

Additional optional features of the system include wind diverter 36, wind blocking furling system 38 and wind straightening grid 30. Wind diverter 36 is a solid member or at least an inclined surface that prevents the wind from contacting the lower half of turbine blade 31 located in the region indicated by arrow 33. This decreases the drag on the back of the blade that is not involved in power generation. Also, diverter 36 directs wind around the back of scoop- shaped blade 31 into the preferred (intended) wind entrance opening of scoop-shaped blade 35 to increase the amount of air involved in power generation.

Furling system 38 is a surface that can be extended and retracted to block none, some, or essentially all of the wind from entering into the inlet to the turbines (in this case, into the active scoop side 39 of blade 35). Furling system 38 is thus useful to act essentially as a speed limiter or governor for the turbines to prevent them from spinning the generator too fast. An example of a furling system is explained in more detail below.

Straightener 30 is optional, and acts to reduce turbulence. It can be accomplished as an open grid with some depth in the direction of the air flow I. In one example the depth is approximately equal to the width of the grid openings. The openings can be, for example, rectangular, square or hexagonal.

A more detailed embodiment 50 is shown in Figures 2 through 6. This embodiment includes central free-standing section 56 that carries the turbines and optionally a furling system, free-standing entrance augmenter 52, and free-standing exit diffuser or reverse funnel 54. These drawings also show more of the constructional aspects of one non-limiting embodiment of the inventive system. The system can be supported at an appropriate height off the ground by the use of cement piers or pillars such as piers 60-63 and supported vertical structural members 64-67, respectively, for inlet augmenter 52 that defines wind entrance 14a and wind exit 51. All of the vertical structural members that support the inlet augmenter and the outlet diffuser can be wooden telephone poles, steel beams, or even bamboo members. When bamboo is used, two or more bamboo poles can be lashed or held together, preferably in a manner such that the joints of adjacent poles do not overlap so that the bamboo doesn't define weakened areas at these joints. The construction typically also comprises additional structural framing, much as a wood-frame house, using, for example, 2" by 6" wood framing members along the side walls, the upper wall or roof 68, and the bottom angled wall 70. Walls 68 and 70 can be covered by external-grade plywood, canvas, plastic sheeting, sheet metal, bamboo or other solid or mostly solid materials, for example. For use in cold weather climates, at least the roof 68 can be made of sheet metal which can be heated for example using electrical heat trace, to prevent buildup of snow and ice.

Central section 56 can be similarly constructed (e.g., with piers 82 and 83), and is preferably an open rectangular construction comprising appropriate vertical (e.g., 81) and horizontal (e.g., 80) structural members, and preferably but not necessarily a flat roof and enclosed side walls (not shown). In this case, the outer sections 84 and 86 can carry the furling system and the turbines, respectively. Alternatively, there can be two sets of turbines that are sequentially exposed to the wind, one carried by section 84 and one carried by section 86.

This embodiment also illustrates another alternative feature of the invention: wind dump panels that can be located in one or both sides and/or the roof 68 and/or the lower surface 70 of the inlet augmenter 52 and/or the outlet diffuser 54. The illustration shows five dump panels in each of the sides of augmenter 52 and diffuser 54, although none, more or fewer dump panels can be used, depending on the need to control the speed of wind exiting the inlet augmenter and contacting the turbines, and the direction of the air flow at the turbines. Dump panel 72 is an example. It can be accomplished with a flap or panel 76 that hangs from structural member 74, using appropriate hinging and blocking construction such that the flap can blow outward but is blocked from blowing inward. Spring force can be used to create a desired pressure differential needed to open the flap if the weight of the flap is insufficient to do so. The flap system can be used to direct air out of the augmenter if the wind force is sufficiently great to overcome the flaps' opening pressure differential.

A similar wind-dumping arrangement can be accomplished in roof 68 and potentially in the roof of diffuser 54 as shown in Figures 3 and 4. In this example, the roof is divided into three sections that span the width of the roof, sections 111, 112, and 113. Each section may comprise one or more canvas panels (e.g., panel 118) that are carried on a wire, line, strut or other elongated supporting structure 116. The trailing edge 117 overlaps the next row. In other words, edge 117 overlaps row 112. When the pressure is sufficiently great, this flap 111 will lift up off of flap 112, thus creating an opening between the two flaps through which wind can escape. All three flaps 111-113 can open and close in this manner.

Figure 5 shows one example of many possible arrangements of wind turbines and generators for use in the invention. In this example, electricity generation system 86 comprises a plurality of vertical-axis wind turbines arranged in a plurality of arrays. For example, generating array 90 comprises four spaced turbines 92-95 that are each carried on rotatable shaft 98 that is coupled to generator 100. A bearing and bushing is located at each intersection of shaft 98 and where it is supported by each of the cross (horizontal) structural members such as members 102 and 104. For example, bearing and bushing 106 is located between turbines 92 and 93 where shaft 98 is coupled to horizontal member 104. This construction supports shaft 98 at a plurality of locations along its length (including between the turbines), thus leading to less vibration and wear of the shaft and better coupling into and less wear of generator 100. This arrangement with the plurality of turbines carried on a plurality of vertical shafts can be accomplished within the area defined at or just beyond the narrow or outlet end of the inlet augmenter 52. The construction of generator system 86 can be similar to the construction of the rest of the system, with the use of telephone poles or other low cost vertical structural members with wood framing used for the horizontal members. Alternatively, steel beams can be used for the entire structural construction of system 86 so that the turbines and generators can be held solidly in place against the sometimes large forces created as the wind contacts the turbines.

The turbines themselves are typically of the VAWT type, essentially defining a cylinder as they spin. Examples are shown in more detail below. The turbines are preferably low-cost construction Savonius-type wind turbines, such as shown, for example, in U.S. patent numbers 1,697,574, 5,525,037 and 7,696,635. The disclosure of each of these patents is incorporated herein by reference. Darrieus-type turbines, or indeed other designs, can also be used; other examples of appropriate turbines can be found in U.S. patent numbers 6,864,597 and 7,679,209. The disclosure of each of these patents is incorporated herein by reference.

Figure 6 shows the augmenter entrance of one embodiment. Four vertical supports such as support 64 that project about 40 feet in the air are spaced apart by 10 feet to define an entrance that is about 30 x 30 feet. Horizontal structural members such as member 132 are shown. There is preferably a flow straightener 130 located at the entrance. The flow straightener is a honeycomb-like structure of the type known in the art of wind tunnels. In this example, it comprises a series of vertical and horizontal planar members that create box-shaped square or rectangular tunnels that are about two feet by two feet at the opening and have a depth of about two feet. This structure forces the air into a more laminar flow, thus reducing turbulence which leads to inefficiencies in turbines. The smoothly tapered upper and lower walls of the augmenter compress the air as the area decreases in a 6: 1 ratio, to increase the speed of the air up to about three times. As the power produced by a wind turbine is related to the cube of the wind speed, this can increase power output by up to about twenty-seven times the power output that could be accomplished without the use of the augmenter.

. Another arrangement of the turbines that can be used in the invention is shown in Figures 7, 8A and 8B. Figure 7 is a top view of one horizontal shaft 158 that carries four identical turbines such as turbine 156. Shaft 158 terminates at generator 160. Structural members such as members 152 and 154 carry the shaft, turbines and generator. Turbine array 150 would typically have a width equal to the width of the augmenter, which in the case of the augmenter shown in Figure 6 is about 30 feet. The area defined by generator array 150 is shown as the elongated rectangular area 140 (figure 6) that is delineated by dashed lines. This area is about five feet high, thus about 1/6 of the 30 foot opening. Depending on the size and arrangement of the turbines, one or more horizontal turbine arrays such as shown in Figure 7 can be located in area 140. Also, more than one array (or sets of arrays) can be arranged sequentially along the air flow path (perhaps but not necessarily with some vertical offset), to better take advantage of the airflow exiting the entrance augmenter.

A simple turbine design that can be used in array 150, or indeed in any of the inventive systems, is shown in Figures 8A and 8B. Turbine 156 is essentially an open-ended box-like structure comprising interconnected walls 170, 171, 173 and 175. The box can be, for example, about 28 inches wide, 42 inches long and 28 inches deep. Angled plate 172 closes the opening. The angle of plate 172 accomplishes a scoop at opposite ends of the two faces. This scoop captures the air, causing the rotation that rotates shaft 158.

An embodiment of a furling system 200 for the invention is shown in Figures 9A-9D. Figure 9A is a side view of structure 202 that structurally supports and carries the movable wind blocker of the furling system. Wind flow direction is indicated by arrow I. The structure is constructed in an appropriate manner to support the size of the system, and the force load on the movable wind blocker. The movable blocker of the furling system in this embodiment is essentially a door (like a garage door of the type that moves up and down along a track) that is moveable from a position in which it doesn't block any of the open area that leads to the turbines, to a position in which is blocks most or all of this area, with controllable positions between those two extremes.

An embodiment of the furling system is depicted in Figure 9 A with the wind blocker in the fully open position, in which the wind is not blocked at all from reaching the turbines. Rolling door 210 with bottom edge 211 is moved up and down in the direction of arrow 220 along a track or other guide that runs on one or more vertical members 241. Upper limit switch 224 and lower limit switch 222 define the two extreme positions of door 210. The door can be located at any position between those two extremes. In this example, this motion is accomplished using a winch motor 212 held by base 214. Winch 212 winds and unwinds cable 216 that runs over idler pulley 218. Door 210 carries at its top center a pivoting link 213 to which cable 216 is coupled.

In the case of the embodiment shown in earlier figures with the augmenter inlet shown in Figure 6, door 210 comprises three identical vertical sections, each of which defines along both elongated sides a series of rollers 232 that fit in "C" - shaped tracks (not shown) that are coupled to the vertical structural members 241. Door 210 thus rides up and down much like a retractable garage door. However, as the door always remains vertical, the door does not need to be sectioned into a number of mutually hinged horizontal sections. Thus, door 210 can be a solid structure. Preferably, door 210 comprises a frame 209 of steel tubing with plywood or other exterior-grade sheathing bolted to it.

This furling system preferably operates as follows: A control system is input with the output of the electrical generator or generators. When the wind speed is too high and the generator is producing more electricity than it is rated for, the furling system moves the door to block an appropriate amount of the opening that leads to the turbines. The control can be proportional or some other type of control. For example, if the output is ten percent over the rated maximum, the door may be moved so that ten percent of the opening is blocked. Alternatively, there can be a proportional feedback control that moves the door appropriately.

The furling system can be accomplished in other manners. For lower wind speeds, a flexible furling system almost like a large window shade can be used, with the blocking structure made of canvas or other flexible material that is rolled and unrolled onto one or perhaps two driven rollers. In one example, one driven roller can be located at the bottom of structure 202 and one at the top, with the flexible blocking sheet moved appropriately along one or more tracks or guides between the two.

An alternative to inhibit running a generator above its rated output is to use an electromagnetic clutch, for example to fully or partially disengage the generator from the shaft at a particular speed. A clutch can maintain a particular speed of rotation of the generator shaft. One design could use a gearbox and clutch between the shaft and the generator. An alternative would be to have one or more clutches located between turbines so as to achieve a more desired power output over a wider range of wind speeds, similar to a variable electronic control. In this case a clutch could disengage a turbine in order to prevent its over-speed. This can be used instead of a furling system, although the furling system has the additional advantage of limiting the forces on the turbines, the rotating shafts and other aspects of the turbine arrays, which can perhaps allow for a less robust physical structure needed to support the turbine arrays, and thus a lower-cost system.

Additional and alternative features for the invention include the following:

• Wind directing panels can be located at the entrance to the augmenter, arranged to allow flow only into the mouth of the augmenter and block flow in the reverse direction.

• Electronic controls could be provided to optimally position wind dump or directing panels in order to channel the wind into the desired areas of the turbines; these could be, essentially, controlled wind diverters that either blocked wind coming from the wrong direction or redirected wind to the active regions of the turbines.

• Helium or cold-air filled balloons could be used instead of augmenters to direct and channel the wind, and/or accelerate the wind into the turbines. This avoids the construction of an augmenter using balloons of proper shapes and sizes. • A transmission or an automatic transmission can be used as a substitute for the furling or the clutch system.

Other embodiments will occur to those skilled in the art and are within the scope of the claims. What is claimed is:

Claims

1. A system for generating electrical energy using wind power, comprising: an entrance wind augmenter comprising a fixed structure supported above the ground that defines an inlet opening defining an inlet area, an outlet opening defining an outlet area that is substantially smaller than the inlet area, and a plurality of fully or partially closed side walls, at least two such side walls being angled from the horizontal so as to create an inwardly-tapered funnel; and an electricity generation system comprising a fixed structure supported above the ground that supports a plurality of generating arrays located proximate the outlet opening of the entrance wind augmenter, each generating array comprising a plurality of wind turbines mounted on a rotatable shaft, and an electrical generator having a rotor that is turned by the shaft.

2. The system of claim 1 in which the entrance wind augmenter defines one or more selectively opened panels along one or more sides, to provide a path for wind to escape the augmenter should its force be too great.

3. The system of claim 1 in which one or more of the angled walls of the entrance wind augmenter comprise and upper wall and a lower wall that lie at an angle of about 22 degrees from the horizontal.

4. The system of claim 1 further comprising an exit wind diffuser comprising a fixed structure supported above the ground that defines an inlet opening defining an inlet area, an outlet opening defining an outlet area that is substantially larger than the inlet area, and a plurality of fully or partially closed side walls, at least two such side walls being angled from the horizontal so as to create an outwardly-tapered funnel.

5. The system of claim 4 in which the exit wind diffuser defines one or more selectively opened panels along one or more sides, to provide a path for wind to escape the diffuser should its force be too great.

6. The system of claim 4 in which one or more of the angled walls of the exit wind diffuser lie at an angle of about 22 degrees from the horizontal.

7. The system of claim 1 in which the wind turbines define preferred wind entrances, the system further comprising a wind diverter constructed and arranged so as to divert wind toward the entrances into the wind turbines and away from areas in which it counteracts turbine rotation.

8. The system of claim 1 further comprising a furling system that selectively blocks wind from reaching the turbines.

9. The system of claim 8 in which the furling system comprises a movable partition located between the outlet opening of the entrance wind augmenter and the turbines.

10. The system of claim 9 in which the partition comprises a flat structural member.

11. The system of claim 10 in which the furling system further comprises a motor to move the structural member up and down.

12. The system of claim 11 in which the furling system further comprises a controller that controls the motor based on the output of the generator.

13. The system of claim 1 in which the shafts are horizontal.

14. The system of claim 13 in which the turbines are Savonius-type turbines that define a generally cylindrical volume in which they rotate.

15. A system for generating electrical energy using wind power, comprising: an entrance wind augmenter comprising a fixed structure supported above the ground that defines an inlet opening defining an inlet area, an outlet opening defining an outlet area that is substantially smaller than the inlet area, and a plurality of fully or partially closed side walls including an upper wall and a lower wall, at least the upper and lower walls being angled from the horizontal at about 22 degrees so as to create an inwardly-tapered funnel with either straight or angled sides; an electricity generation system comprising a fixed structure supported above the ground that supports a plurality of generating arrays located proximate the outlet opening of the entrance wind augmenter, each generating array comprising a plurality of Savonius-type wind turbines that define preferred wind entrances, and a generally cylindrical volume in which they rotate, wherein the turbines are mounted on a rotatable horizontal shaft, and an electrical generator having a rotor that is turned by the shaft; an exit wind diffuser comprising a fixed structure supported above the ground that defines an inlet opening defining an inlet area, an outlet opening defining an outlet area that is substantially larger than the inlet area, and a plurality of fully or partially closed side walls, at least one such side wall being angled from the horizontal so as to create an outwardly-tapered funnel, in which one or more of the angled walls of the exit wind diffuser lie at an angle of about 22 degrees from the horizontal; a wind diverter constructed and arranged so as to divert wind toward the entrances into the wind turbines and away from areas in which the wind counteracts turbine rotation; and a furling system that selectively blocks wind from reaching the turbines, the furling system comprising a movable partition located between the outlet opening of the entrance wind augmenter and the turbines, a motor to move the partition up and down and a controller that controls the motor based on the output of the generator.