This invention relates to methods and apparatuses related to a solar electricity generating apparatus and such an apparatus in combination with a wind turbine electricity generating apparatus.
Both solar arrays and wind turbines for generating electricity are known, but each has several disadvantageous features primarily due to their large size and unsightly appearance. Although solar panels can be roof-mounted and their appearance somewhat obscured, wind turbines are especially problematic in this regard. They are constructed hundreds of feet from the ground and to generate a maximum amount of electricity the turbine blades are typically several feet across. Thus wind farms, comprising many such wind turbines, are located away from residential and business areas.
The present invention can be more easily understood and the further advantages and uses thereof more readily apparent, when considered in view of the following detailed description when read in conjunction with the following figures. In accordance with common practice, the various described features are not drawn to scale, but are drawn to emphasize specific features relevant to the invention. Reference characters denote like elements throughout the figures and text.
Before describing in detail the particular methods and apparatuses related to a combination solar and wind generating apparatus (i.e., a solar wind tree) it should be observed that the present invention resides primarily in a novel and non-obvious combination of elements and process steps. So as not to obscure the disclosure with details that will be readily apparent to those skilled in the art, certain conventional elements and steps have been presented with lesser detail, while the drawings and the specification describe in greater detail other elements and steps pertinent to understanding the inventions. The presented embodiments are not intended to define limits as to the structures, elements or methods of the inventions, but only to provide exemplary constructions. The embodiments are permissive rather than mandatory and illustrative rather than exhaustive.
It would be beneficial to develop a combination wind and solar electricity generating apparatus for maximizing the amount of electricity generated from our natural resources and further having an appearance that is aesthetically pleasing. Such an aesthetically pleasing generating apparatus can be located within a residential or commercial area. With the source of electricity proximate the user of electricity, losses during transmission of the electricity are drastically reduced. The homeowner or business owner can take responsibility and control the generation of electricity for personal/business consumption.
One of the present inventors was suddenly struck by the idea of a solar wind tree while riding on a train just west of Amsterdam in the Netherlands two years ago. He observed the large number of wind turbines already in use and clearly visible from the train.
As the train stopped at a small station the inventor noticed the trees next to the platform and observed the breeze blowing through the trees. He observed that every tree leaf was moving while at the same time nearly every leaf was exposed to the bright sunlight overhead. It occurred to this inventor that if one could capture both the solar energy and wind energy using a “tree” one might be able to maximize the benefit of both forms of environmentally friendly energy.
He then questioned why one could not configure both solar panels and wind turbines in the form of a tree and thus maximize use of both the wind turbines and the solar panels from a single structure. Additionally, such a solar/wind generator in the form of a tree, or another natural or man-made object, can be designed and constructed to be aesthetically pleasing to the eye by incorporating design elements that imitate foliage and soften the visual effects of the “tree.”
As illustrated in
In the illustrated embodiment the blades 16 of each wind turbine 14 are substantially perpendicular to the ground. Both the blade angle relative to the ground and the blade pitch may be adjustable.
In both the embodiments of
Also, in the embodiments of both
Taking advantage of the natural shape of a pine tree, for example, the solar/wind tree 10/23 narrows in a direction toward the apex or top so that higher-mounted solar collectors 12 do not obscure the sunlight from lower-mounted collectors 12. In this embodiment the solar collectors are slightly curved to enhance sunlight capture as the sun moves across the sky and to present an airfoil-like structure that directs the wind to the turbines of the solar/wind tree. An airfoil shape is selected to maximize the velocity of the wind striking the wind turbine blades. Other shapes beyond the concave shapes illustrated may be used. The curve of the solar collector may be concave or convex (or substantially flat) depending on the design that optimizes electricity produced by the solar collectors 12 and the wind turbines 14/24.
In another embodiment the orientation of each solar collector 12 is automatically controlled to track the sun as it traverses the sky. For example, the tilt angle (the angle of each solar collector with respect to a vertical line) is controllable to maximize sun exposure. Also, an angle of each blade for each wind turbine 14/24 and the angle of the rotational axis are controllable to optimize the direction at which the wind strikes the blades. For example, the rotational axis may be horizontal as illustrated in
The wind turbines 14/24 each comprise a plurality of blades extending from a rotating drive shaft that turns an electricity-generating generator. The generator may produce alternating or direct current, and operates according to commutation and induction principles as is known to those skilled in the art. The present invention is intended to encompass all types of apparatuses for generating electricity from solar and wind sources.
In another embodiment, a wind turbine comprises a plurality of surfaces each having one edge joined in a radial pattern to a central drive shaft (e.g., a paddle wheel). As the wind strikes the paddles, the drive shaft turns and drives the electrical generator connected thereto.
Use of different turbine designs and different turbine blade designs to maximize turbine efficiency and power output depends on the specific installation and orientation details and anticipated wind speeds. Ideally the solar collector 12 incorporates an airfoil-like design, for example comprising a small “wing,” to increase the wind speed and direct the wind stream on to the wind turbine blades. The turbine will therefore more efficiently “harvest” the maximum output from the available wind.
It is preferable that the overall solar/wind tree design be compatible with installation in a typical neighborhood; the visual design component is therefore important. The overall structure, in one embodiment, is predominantly green in color with dark solar collectors. The overall visual impression is intended to blend nicely and look like, in essence, a unique form of a “tree.” One preferable installation includes the yard of a home. Therefore having the ‘tree” blend with the other vegetation may be important. Artificial foliage (leaves, for example) can also be incorporated into the tree 10/23 to soften its visual appearance and make the solar wind tree more esthetically pleasing.
It is known that cell towers are designed to mimic trees in some locations, especially where zoning ordinances prohibit cell towers that do not blend with the natural vegetation. These same objections may be raised against the solar/wind tree of the embodiments of the present invention. Thus the wind turbines and solar energy collectors may be designed to appear as natural vegetation to the cursory viewer. Additionally, the “tree” may include some artificial leaves, branches and other elements to camouflage the wind turbines and solar collectors and make the tree appear more realistic. The ultimate commercial success of the present invention suggests that “being a good neighbor” (e.g., blending with the natural vegetation) is important.
In one embodiment both the solar collectors and the wind turbines generate DC electricity allowing use of a single power conductor to emerge from the solar wind tree. The DC electricity is converted to 60 Hz AC electricity in an inverter (not shown) for direct use by a consumer or for input to the electrical grid. The inverter and associated controls can be located at the base of “tree” or in a separate proximate structure.
The size of the tree generally determines the overall energy output from the wind turbines 14/24 and the solar collectors 12. Although a large tree(s) might be desirable, zoning codes or neighborhood aesthetics may limit “tree” size. A taller tree provides a higher wind turbine efficiency since the wind speed generally increases as a function of distance from the ground. In one embodiment the wind turbines are installed only on the upper levels of the tree where the wind is more effective in generating usable power. The solar component operates at about the same efficiency irrespective of distance from the ground.
Generally, it is desired that no or few obstructions be placed in the wind path to the wind turbines. For a typical home in Los Angeles that uses approximately 7300 kWh per year, three 21 ft. tall trees may be required. This is calculated by assuming a solar output of about 10 watts/square foot, requiring about 100 square feet of solar collectors for each annual kWh demand. If one assumes the radius of each tree is about seven feet then each tree presents an area of approximately 153 square feet facing the sun. Since about half of the collectors may not be oriented in the optimal sun position, the inventors estimate that the solar collector portion of three trees will provide just over 3 kWh per year with the balance of energy being provided by the wind turbines. This should cover approximately 75% of the power usage of a typical home in the Los Angeles area.
In another embodiment, a solar/wind tree 70 comprises a plurality of ring-like film solar collectors 72 that encircle a tree trunk 76. See the top-down view of
The open space between two successive solar rings 72 may also create an area for mounting the wind turbines 14/24 as illustrated in
In an area with no or a small wind component, the “tree” of the present invention may comprise a solar tree rather than a solar/wind tree. In this case, additional trees may be required to compensate for the lack of wind turbines. Such an embodiment, illustrated in
In another embodiment, a tree of the present invention features only turbines and no solar collectors, for example, the embodiments of
Another embodiment of a solar/wind tree 100 is illustrated in
The various presented embodiments of the solar/wind tree may not offer the most efficient design in generating a maximum amount of solar and wind energy for the homeowner. But the use of several such solar/wind trees on a parcel of property offers a simpler and perhaps a more economical (i.e., lower installation and use costs) apparatus to cover the homeowner's power costs, compared with installing roof mounted solar collectors or installing an unsightly 50-foot tower with a top-mounted wind turbine. Thus the present invention offers a solution that is “about right” when all factors are considered, including the aesthetics of the solar/wind tree and the generating efficiency. To improve the “look” of the tree, it may incorporate artificial leaves and branches (even pine cones in one embodiment) so that the completed structure has the look and feel of a real tree. The solar/wind tree can also be adapted to look like the trees or other vegetation in any particular region of the country.
According to another embodiment of the invention, as depicted in
According to this embodiment, electricity generating components (e.g., stator, rotor, etc.) present in both the hub 305 and proximate regions of the vertical shaft 18 interact to generate electricity.
Although the illustrated embodiment depicts three blades 304 within each wind turbine 302, each wind turbine 302 can comprise any number of blades 304. Also, any number of wind turbines 302 (three illustrated in
To generate electricity most efficiently, the number, location, and size of the wind turbines 302, the number, shape and size of blades 304, and the number and location of the solar collectors 312 are determined after analysis of the site wind and solar conditions, including expected wind direction and velocity.
The solar wind apparatus 300 can be of conventional design (i.e., the blades are connected to the shaft 18 (or to a plurality of such shafts)) that cause the generator to turn, with the generator installed either proximate the wind turbine 302 or at a base of the solar/wind tree 300. In one embodiment the generator comprises a gearless blade tip power system available from Honeywell International of Morristown, N.J. as described below. In another embodiment a helical wind turbine as depicted in
In yet another embodiment stator windings (not shown) are disposed within rings 326 disposed beyond the circumference of the blades 304. The rings are affixed to the shaft 18 by support components not illustrated, such as support ribs having a first end extending downwardly and at an angle from a bottom surface of each ring 326 and a second end affixed to the shaft 18. In this embodiment permanent or electromagnets are installed at a tip of each blade 304. Current is generated in the stator windings as the blades 304 are turned by the wind energy.
A gearless blade tip power system available from Honeywell International of Morristown, N.J. is one type of wind turbine that can be used with certain embodiments of the present invention. This wind turbine utilizes a system of magnets and stators disposed on an outer ring, thereby capturing power at the blade tips. Rather than forcing the wind to turn a generator, the perimeter power system becomes the generator by passing blade tip magnets through copper coil banks mounted onto a perimeter frame.
Regardless of the selected generator, one embodiment 339 employs a cage or wire mesh 340 surrounding the wind turbine 300 to protect birds and small animals from the spinning blades. See
The solar collectors in any of the presented embodiments that direct the wind stream onto the wind turbine blades can be concave, convex, or flat, and with variable dimensions as appropriate to maximize wind velocity impinging the wind turbines. For example, the collectors can have a larger dimension along an edge of a surface nearer the base of the tree. Again, the ideal shape is determined by wind conditions at the site of the solar/wind tree.
It is expected that there may be a cumulative effect as the wind passes through several levels of wind turbines as depicted in the various figures. In effect, the wind directed upwardly from lower levels adds to the wind directed toward upper level wind turbines, thereby having a positive effect on the efficiency of the solar/wind power generating apparatus. The air stream enters the solar/wind turbine at a relatively low pressure and exiting at a higher pressure. Again, shaping of the solar collectors for optimum wind flow must consider trade-offs between efficiency for proximate and distance wind turbines.
A solar wind apparatus according to one embodiment may be open at the top or apex to allow wind to exit the solar wind tree without restriction to improve the efficiency of the wind tree.
As in the various embodiments described herein, the wind streams 420 cause the turbine blades 410 to rotate and thereby generate electricity in the generator 424. The solar energy collecting skirts 402 generate electricity from the sun's radiant energy impinging the skirts 402 from any direction.
As air entering the apparatus 400 rises (increasing pressure and velocity) through inside surfaces of the solar collecting skirts 402, it is heated as it contacts these surfaces. This “chimney effect” causes additional energy to be generated by the wind turbines 406 in cooperation with the generator 424.
As in the other described embodiments, a pitch of the turbine blades 410 can be controlled to extract maximum energy from the wind stream. Also, although the wind turbines 406 are depicted as situated at a top surface of each of the solar collecting skirts 402, this is not required as the wind turbines 406 can be positioned at different distances along the vertical height of the skirts 402 or between two skirts 402 as dictated by local wind and solar energy conditions and as desired for efficient operation.
The various embodiments described herein are expected to maximize the energy generated for a given footprint, since both solar and wind energy are harvested from the same device in certain of the embodiments.
Associated devices for metering and/or energy storage can be located at the base of the solar wind tree or separately.
The vertical shaft (such as reference numeral 18 in
The various illustrated embodiments may comprise elements (leaves, bark, branches, stems, trunks) that are intended to camouflage the solar energy collectors and the wind turbines and their associated devices. The color, surface texture, size, and appearance of the solar energy collectors, the wind turbines and their associated devices may be selected to appear as vegetation. In
A solar/wind tree “farm” or “grove” comprises multiple, relatively closely spaced, solar/wind trees. In a commercial solar/wind tree farm the aesthetic elements may be minimized in an effort to generate the maximum amount of wind and solar energy available at the site. The solar/wind trees are spaced so that the maximum wind and solar energy is gathered at each solar/wind tree.
Many of the described embodiments include both solar panels and wind turbines. However, this is not required as the inventive features can be applied separately to create a solar tree for generating electricity from solar energy and a wind tree for generating electricity from wind energy. In either case, the “tree” can include vegetation that camouflages the solar panels and/or wind turbines and makes the “tree” appear more realistic. In yet another embodiment, the arrangement of solar panels and/or wind turbines may be oriented in a shape that does not resemble a tree.
Many of the presented embodiments have been illustrated as having a conical tree shape such as a pine tree. When camouflaged to resemble any large plant species, including in both shape and size, these embodiments tend to be aesthetically pleasing. However, this feature is not intended to limit the scope of the present invention nor is it intended to be present in all embodiments. Instead, all wind turbines along the vertical can be the same size and shape and in yet another embodiment the wind turbines can be inverted from the illustrated configurations, i.e., the uppermost wind turbine having a larger diameter than the lowermost wind turbine.
Also, it is not necessary to alternate the solar collectors and the wind turbines, although it may be preferable to arrange the collectors and turbines in a conical shape so that upper solar collectors do not shield lower solar collectors from the solar energy. Those skilled in the art of generators and wind turbines recognize that any of several different generator types (and coil windings) may be used in conjunction with the wind turbine to generate electricity. Any of these generator and winding types are within the scope of the present invention.
In certain of the embodiments vegetation elements are not shown in the respective figure(s). However elements can be added, such as illustrated in
While the invention has been described with reference to preferred embodiments, it will be understood by those skilled in the art that various changes may be made and equivalent elements may be substituted for elements thereof without departing from the scope of the present invention. The scope of the present invention further includes any combination of the elements from the various embodiments set forth. In addition, modifications may be made to adapt a particular situation to the teachings of the present invention without departing from its essential scope. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.
This patent application is a continuation-in-part application claiming priority to the application filed on Feb. 22, 2010, assigned application Ser. No. 12/710,331 and entitled Solar Wind Tree, (now ______), which claims priority to the provisional patent application No. 61/154,390 filed on Feb. 21, 2009, entitled Solar Wind Tree.
Number | Date | Country | |
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Parent | 12710331 | Feb 2010 | US |
Child | 13942473 | US |