WIND GENERATOR

Abstract

Integrated wind-photovoltaic system for the production of electrical energy, the system comprising a wind generator equipped with a semi-vertical axis provided, in turn, with wind blades having a back, wherein the back of the aerodynamic profile of these wind blades is at least partially provided with a covering consisting of flexible photovoltaic panels, and wherein a sunlight concentration optical system is provided comprising a plurality of coplanar lenses.

Claims

1. An integrated wind-photovoltaic system for the production of electrical energy, the system comprising a wind generator equipped with a semi-vertical axis provided, in turn, with wind blades having a back, wherein the back of the aerodynamic profile of these wind blades is at least partially provided with a covering consisting of flexible photovoltaic panels, and wherein a sunlight concentration optical system is provided comprising a plurality of coplanar lenses.

2. The system according to claim 1, wherein the solar radiation concentration optical system is arranged on two separate parallel planes spaced from each other, a ratio between the distance between these planes and the maximum diameter of the rotor being between 1/10 and , preferably .

3. The system according to claim 2, wherein the optical system includes a concentric polygonal matrix consisting of high-strength belts tensioned between a central ring and coupling brackets provided at the tops of the wind blades.

4. The system according to claim 3, wherein the optical system includes a plurality of concentration Fresnel lenses, with an average value factor of sunlight concentration between 40 and 60.

5. The system according to claim 4, wherein the concentration Fresnel lenses include prismatic modules with large angles of incident radiation acceptance, being preferably up to 25.

6. The system according to claim 5, wherein the concentration Fresnel lenses have an upper layer made of a polymethyl methacrylate polymer, which defines an upper face of the lens, this upper face being the face exposed to solar radiation, and a lower layer made of polycarbonate and having a multi-prismatic configuration, which defines an opposite lower face, these lenses having a high radiation transmittance coefficient greater than 90%.

7. The system according to claim 6, wherein the covering consisting of flexible photovoltaic panels covers a large longitudinal area of the back of the wind blades, and wherein the panels are joined along the aerodynamic profile of the blade itself.

8. The system according to claim 7, wherein the flexible photovoltaic panels include flexible multi-junction photovoltaic panels, with gallium nitride (GaN)-indium gallium nitride (InGaN) for high temperatures, with high electrical conversion efficiency, higher than 45%, for the spectrum between 400 and 1000 nm wavelength.

9. The system according to claim 8, wherein the wind blades comprising a covering consisting of flexible photovoltaic panels are made of an aluminum alloy so as to promote heat dissipation of the heat that is generated in correspondence of these panels and increase the yield of electrical conversion, even in case of prolonged use.

10. The system according to claim 9, wherein the wind blades include an elongated hollow body open at both ends and are equipped, at the upper ends of the blades, with a nozzle that discharges the airflow passing through the blades.

11. The system according to claim 10, wherein the electrical energy generated by the photovoltaic panels is conveyed towards a management inverter through a brushes-collector system arranged between the rotor and the support for the hub, the brushes-collector system including a rotating collector ring, associated with the wind rotor, to which the electrical cables coming from the photovoltaic panels and brushes attached to a fixed structure or pedestal rotatably supporting said wind rotor.

12. The system according to claim 11, wherein the electrical energy generated by the wind generator is conveyed into the inverter into which the electrical energy generated by the photovoltaic panels is conveyed, the inverter being electrically connected to a system control panel.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Some preferred embodiments of the invention will be provided by way of non-limiting example with reference to the annexed drawings, in which:

[0033] FIG. 1 is a partial side view of the system according to a preferred embodiment of the invention;

[0034] FIG. 2A is a top plan view of the polygonal matrix supporting the lenses of the optical system;

[0035] FIG. 2B is a top plan view of a lens in FIG. 2A;

[0036] FIG. 2C is a sectional view taken along a transverse plane of the lens in FIG. 2B;

[0037] FIG. 3A is a front view of a blade of the rotor of the wind generator in FIG. 1;

[0038] FIG. 3B is a perspective view from above of the nozzle of the wind blades in FIG. 3A;

[0039] FIG. 3C is a side view of the nozzle in FIG. 3B;

[0040] FIG. 3D is a cross-sectional view of the wind blade in FIG. 3A;

[0041] FIG. 3E is a partially sectional view of a coupling bracket provided at the top of the wind blade in FIG. 3A;

[0042] FIG. 4 is an overall side view of the system according to the invention.

DETAILED DESCRIPTION

[0043] Referring to FIG. 1, the arrangement of the integrated wind-photovoltaic system for the production of electrical energy according to the invention is illustrated. The wind-photovoltaic system for the production of electrical energy comprises a wind generator 100 including a rotor 110 having a semi-vertical axis Y-Y and provided, in turn, with wind blades 2. The wind blades 2 include a body having a first lower end, proximal to the rotor hub 1 of the rotor 110 and constrained thereto, and a second upper end or top, distal to the hub 1 of the rotor 110. These wind blades 2 can preferably be from 2 and 7 in number and are preferably inclined at an angle between 30 and 60 relative to the vertical axis Y-Y of the rotor 110 of the wind generator 100. In the illustrated embodiment, the wind blades 2 are arranged in a substantially V-like configuration so as to form a substantially frustoconical structure with the minor base arranged below, relative to the vertical rotation axis Y-Y of the rotor 110. The blades 2, below, are constrained to the hub 1 of the rotor 110 and, above, include a coupling bracket 3.

[0044] Advantageously, the wind-photovoltaic system according to the invention integrates in a single machine the double function of a semi-vertical wind generator and a solar radiation collector. To this aim, the system according to the invention includes a coating consisting of photovoltaic panels 8 and covering at least part of the surface of the back 2 of the aerodynamic profile of the blades 2. The photovoltaic panels 8 are also joined along the aerodynamic profile of the blade itself. The photovoltaic panels 8 include flexible photovoltaic panels. The flexibility of these photovoltaic panels 8 advantageously allows perfect adhesion to the back 2, usually curvilinear, of the blades 2.

[0045] A type of photovoltaic panel particularly suitable for the purpose of the invention includes flexible multi junction photovoltaic panels, with gallium nitride (GaN)-indium gallium nitride (InGaN) for high temperatures. These panels typically have high electrical conversion efficiency, higher than 45%, for the spectrum between 400 and 1000 nm wavelength.

[0046] Advantageously, according to the invention, the solar radiation h.sub.v is concentrated by using a special optical system or optical structure with sunlight concentration. The optical system comprises a plurality of coplanar lenses 5 connected at the top apical region of the blades 2 of the wind generator 100.

[0047] Advantageously, the optical system for concentrating and focusing the light h.sub.v on the photovoltaic panels 2 consists of several planes 6, 6 of concentration Fresnel lenses 5 arranged in vertical succession along the rotation axis Y-Y of the rotor 110. In addition, the optical system includes a concentric polygonal matrix 112, preferably consisting of high-strength belts 4 tensioned between a central ring, arranged coaxial with the vertical rotation axis Y-Y of the rotor 110, and the coupling brackets provided at the upper ends the blades 2. The belts 4 are preferably made of a material based on special Kevlar29+Nylon fibers. The polygonal matrix 112 consisting of belts 4 defines a substantially flat flexible mesh structure 12 on which the concentration Fresnel lenses 5 are attached by means of suitable supports. In the illustrated embodiment, the polygonal matrix consisting of belts 4 defines two separate substantially parallel planes 6, 6, suitably spaced from each other and substantially perpendicular to the vertical rotation axis Y-Y of the rotor 110. According to the invention, the distance between the two planes 6, 6 is chosen so that the ratio between the distance between these planes 6, 6 and the maximum diameter of the rotor 110, i.e. the diameter measured at the circumference passing through the upper ends or tops of the wind blades 2, is between 1/10 and , preferably . A first terminal plane 6 is located in correspondence with the upper zone of the wind blades 2, whereas the second plane 6 is located below said first plane 6 at a distance d suitably chosen according to the diameter of the rotor 110, preferably between 0.2 and 1.0 meters in the example shown. In other embodiments, it will be possible to provide more than two planes of concentration Fresnel lenses, or just one.

[0048] Referring now to FIGS. 2A, 2B and 2C, the system of belts 4 and lens support 112 forming a terminal coplanar structure 6 is shown. In FIGS. 2B and 2C there is illustrated a Fresnel lens 5 used in the making of the optical system, this lens having a substantially rectangular shape and preferably having a width a smaller than a length b. Preferably, these concentration Fresnel lenses 5 have an average value factor of concentration of sunlight h.sub.v, more preferably between 40 and 60. Still according to the invention, the concentration Fresnel lenses 5 include prismatic modules with large angles of acceptance of the incident radiation h.sub.v, 3 being preferably up to 25.

[0049] Flexible photovoltaic panels 8 with high electrical energy generation efficiency are attached to each blade 2, in the back region of the blade oriented towards the coplanar structures 6 e 6.

[0050] Referring to FIGS. 3A to 3E, these illustrate in detail a blade 2, to the back 2 of which the photovoltaic panels 8 are coupled. The blade 2 comprises and elongated body open at both ends and defining an inner cavity 2b. The blade 2 is advantageously made of an aluminum alloy with high thermal conductivity, whereby the blades 2 have a heat sink function for the heat that develops in correspondence of the photovoltaic panels 8 during the solar radiation h.sub.v. In the shown example, the photovoltaic panels 8 cover a longitudinal portion of the back 2 of the blade 2 extending over a length l.sub.p of the overall length l.sub.b of the wind blade 2. In other embodiments, however, it will be possible to provide that the photovoltaic panels cover most of the back surface of the wind blade or, even better, the entire surface of the wind blade.

[0051] The inner cavity 2b of the blade 2 allows the passage of air inside the blade, so that the air, passing though the body of the blade 2, can cool down the photovoltaic panel 8 integrated on the back 2 of the blade 2.

[0052] The flow of heated air passing through the inside of the hollow section 9 of each blade 2 is sucked at room temperature through the lower opening 2a of the blade 2, near the hub 1 of the wind generator, and is discharged at the apex of the blade 2 in correspondence of a suitable nozzle 13 located in a position substantially orthogonal to the axis y.sub.b of the blade 2, after passing through the inner cavity 2b of the blade 2.

[0053] Referring to FIG. 4, the circuit diagram of conveyance of the electrical energy produced by the integrated wind-photovoltaic system according to the invention into the electrical panel 19 is illustrated.

[0054] The electrical energy generated by the photovoltaic panels 8 is conveyed, through electrical cables coming out of the panels 8 and towards the lower end of each blade 2 and connected to a device including a bipolar rotating collector 16 provided with rings integral with the hub 1, and brushes 17 fixed to a support structure 20.

[0055] The central rotating hub 1 is connected to a rotor of an electrical generator 10 connected to an inverter 18 to which the electrical energy from the photovoltaic panels 8 is also conveyed through the brushes 17.

[0056] The invention as described and illustrated is susceptible to several variations and modifications, all of which fall within the same inventive principle.