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Title:
ROTATING PLATFORM AND SOLAR TRACKING SYSTEM FOR PHOTOVOLTAIC (PV) SOLAR PANELS
Document Type and Number:
WIPO Patent Application WO/2012/027418
Kind Code:
A1
Abstract:
A rotating platform (12) carries photovoltaic (pv) solar panels (14) with reflective mirrors (22). The platform (12) is supported for rotation about a single vertical pivot axis (A) by wheels (16) that travel around a circular path (20). The platform (12) automatically rotates, to track the position of the sun as it moves through the sky.

Inventors:
NAWAB, Khurram, K. (1918 Eden Place, Rockford, IL, 61107, US)
Application Number:
US2011/048876
Publication Date:
March 01, 2012
Filing Date:
August 23, 2011
Export Citation:
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Assignee:
NAWAB, Khurram, K. (1918 Eden Place, Rockford, IL, 61107, US)
International Classes:
H01L31/042
Foreign References:
US20080308154A12008-12-18
US20070227574A12007-10-04
US20070272234A12007-11-29
US20100185991A12010-07-22
Attorney, Agent or Firm:
FRANTZ, Keith (401 W State St, Suite 200Rockford, IL, 61101, US)
Download PDF:
Claims:
Claims

1. A tracking system (10) for solar collector devices (14) characterized as comprising: a) a single axis horizontal rotating platform (12) to carry the solar collector devices (14); the platform (12) being rotatably supported for rotation about a vertical axis (A) through a pivot point (18);

b) a set of wheels (16) supporting the platform (12) in a horizontal position;

c) a circular track (20) along which the wheels (16) travel as the platform (12) rotates; and

d) power drive arrangement to rotate the platform (12) to track the sun as it moves across the sky; said power drive arrangement including a controller unit (30)

implementing a platform rotational control algorithm.

2. The tracking system (10) as defined in claim 1 further characterized as wherein the power drive arrangement includes a circular tracking channel (24) tracking channel is located on the underside of the platform (12) and centered about the pivot point (18) of the platform (12), a tracking drum and motor (28) controlled by the controller unit (30), and a set of guide rollers (26) coupled to and rotated by the tracking drum and motor (28) and operatively engaging the tracking channel (24) to rotate the platform (12).

3. The tracking system (10) as defined in claim 1 further characterized as wherein the solar collector device (14) is a pv solar panel, and the tracking system further includes a reflective mirror (22) mounted for pivoting about a horizontal axis (H) to focus additional radiation onto the pv solar panel (14).

4. The tracking system (10) as defined in claim 1 further characterized as wherein the controller unit (30) is programmed to power and rotate the tracking drum and motor (28) according to a time -based algorithm, seasonally and geographically adjusted, to rotate the platform (12) in one direction, from a starting angular position to an ending angular position, during the daylight hours, and return the platform (12) to the starting angular position when daylight hours are passed.

5. The tracking system (10) as defined in claim 1 further characterized as wherein the controller unit (30) includes light-intensity sensors (32) operable for implementation of a platform rotational control algorithm that precisely tracks the position of the sun.

6. A tracking system (50) for solar collector devices (54) characterized as comprising: a) a single axis horizontal rotating platform (52) to carry rows of the solar collector devices (54) and corresponding booster mirrors (72); the platform (52) being rotatably supported for rotation about a vertical axis (A2) through a pivot point (58);

b) a set of wheels (56) supporting the platform (52) in a horizontal position;

c) a circular track (60) along which the wheels (56) travel as the platform (52) rotates; and

d) power drive arrangement to rotate the platform (52) to track the sun as it moves across the sky; said power drive arrangement including a controller unit (30)

implementing a platform rotational control algorithm, including an algorithm to rotate the rows of solar collector devices 54 independently of one another.

Description:
ROTATING PLATFORM AND SOLAR TRACKING SYSTEM FOR

PHOTOVOLTAIC (PV) SOLAR PANELS

Technical Field

The present invention relates to a rotating platform for photovoltaic (pv) solar panels; and to a solar tracking system with a rotating platform for pv solar panels.

Background Art

Photovoltaic (pv) solar panels produce electric power from solar radiation. While sunlight is free and readily available, generating electric power with pv panels is generally more expensive than conventional power generating systems (e.g., coal, nuclear, hydro, etc.). Thus, there is an ever-present need to increase the efficiency and decrease the cost of solar panel electric power generating systems, to reduce the cost of power produced by these systems.

Tracking systems are commonly used to orient pv solar panels towards the sun as it travels across the sky, to increase the incidence of solar radiation onto the panels as the sun changes position in the sky, and thereby increase the energy produced from the panels as compared with the energy that would be produced by panels in a fixed position. Thus, tracking systems can increase the performance efficiency and decrease the cost of energy produced by solar panel electric power generating systems.

The present invention provides a new rotating platform and tracking system that increases the electric generating efficiency and performance of pv solar panels as compared with panels in a fixed position, that is a low cost and relatively simple rotating platform and tracking system, and that reduces the overall cost of energy produced by solar panels.

Disclosure Of Invention

An important objective of the invention is to provide a new and unique rotating platform and tracking system for pv solar panels, to orient the panels towards the sun as it travels across the sky, and thereby increase the absorption of solar radiation and electric generating efficiency of the panels as compared with the energy absorption and efficiency of panels in a fixed position. Another important objectives is to provide a new and unique pv solar panel rotating platform and tracking system of relatively simple design to further promote lower cost generation of electric power.

Additional objectives and advantages achieved by the new rotating platform and tracking system include: (a) the total size of solar panels can be reduced as compared with fixed position panels while achieving the same electrical output, (b) the rotating platform and tracking system can be used with solar panels of the same or different sizes and

configurations at the same time, and (c) each solar panel unit can be individually connected or supported and easily replaced on the platform resulting in reduced maintenance costs for the overall power generating system.

Solar panels are generally sold at cost per unit power output. By virtue of the rotating platform and tracking system, the electrical output of solar panels is increased as compared with solar panels in a fixed position. Thus, the rotating platform and tracking system can reduce the cost of electrical power output of solar panels and result in per unit energy savings.

The preferred rotating platform of the invention is a tracking platform on which panels of photovoltaic (pv) modules are mounted with corresponding pv booster mirrors. Significant advantages of the platform are easy to access, for cleaning the pv modules and booster mirrors, less wind pressure obstruction, 360 degrees rotation, and they are suitable for any location in the world. An ultimate goal is to reduce system operating cost and investment by increasing power output from the system per unit cost.

These and other objectives and advantages of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.

A tracking system, according to the invention, includes a single-axis horizontal rotating platform to carry solar collector devices such as solar panels shown, and power drive arrangement including a control unit to rotate the platform according to a programmed algorithm to track the sun as it moves across the sky, to simultaneously rotate the solar panels and increase the incidence of solar radiation onto the panels as the sun changes position in the sky. Brief Description The Drawings

FIG. 1 is a perspective view of a rotating solar platform and tracking system in accordance with the invention.

FIG. 2 is top schematic representation of the rotating platform and tracking system shown in FIG. 1.

FIG. 3 is a cross-sectional view, taken through the center axis "A" of one embodiment of a suitable pivot assembly for the rotating platform.

FIG. 4 is a top view of the bearing housing shown in FIG. 3.

FIG. 5 is a side cross-sectional view of the bearing housing shown in FIGS. 3-4.

FIG. 6 is a top view of the shaft shown in FIG. 3.

FIG. 7 is a side view of the shaft shown in FIGS. 3 and 6.

FIG. 8 is a side view of a preferred alternate embodiment of a rotating solar platform and tracking system provided with rows of photovoltaic panels equipped with performance enhancing booster mirrors.

FIG. 9 is a front view of the rotating solar platform and tracking system shown in

FIG. 8.

FIG. 10 is a top view of the rotating solar platform and tracking system shown in FIG.

8.

While the invention is susceptible of various modifications and alternative

constructions, certain embodiments are shown in the drawings and described in detail below. It should be understood, however, that there is no intention to limit the invention to the specific forms disclosed, but on the contrary, the intention is to cover all modifications, alternative constructions and methods, and equivalents falling within the spirit and scope of the invention.

Best Modes For Carrying Out The Invention

Referring to FIGS. 1-2, a tracking system 10, according to the invention, includes a single-axis rotating platform 12 to carry solar collector devices 14 such as photovoltaic (pv) solar panels shown, and power drive arrangement to rotate the platform to track the sun as it moves across the sky, to simultaneously rotate the solar panels and increase the incidence of solar radiation onto the panels as the sun changes position in the sky. The platform 12 shown is supported in a horizontal position on a set of wheels 16, to rotate about a vertical axis "A" through pivot point 18. As the platform rotates, the wheels travel around a durable surface on or of a support structure. In the embodiment shown, the wheels travel around a circular track 20 that is formed of a durable material (e.g., concrete, hard plastic, asphalt, etc.) overlaying the ground or the roof of a building or other suitable surface. The pivot point is established by a suitable rotatable platform support arrangement, such as assembly 40 (see FIGS. 3-7) with a pivot shaft 42 secured to and extending downwardly from the underside of the platform, and rotatably supported in bearings 44 in a bearing housing 46 resting on or secured to the ground or other support structure.

The solar panels 14 can be of any convenient size and configuration. The solar panel shown in FIG. 1 is mounted on leg supports on the platform 12. The preferred solar panel 14 includes a reflective mirror 22 that focuses additional solar radiation onto the panel. The mirror is mounted to pivot at horizontal axis "H" so that the angle of the mirrors can be geographically, seasonally and otherwise adjusted, manually or automatically (such as within the controller unit 30 operational control algorithm discussed further below), to optimize the additional solar radiation reflected onto the solar panel and further increase the electrical output from the panel. The pv solar panels are connected with their electrical output in a conventional manner to an inverter or junction to an electrical power grid or electrical using device.

Any suitable power or drive arrangement can be provided to rotate the platform within the scope of the invention. Referring to FIG. 2, one preferred power drive arrangement to rotate the platform shown includes a circular tracking channel 24, a set of guide rollers 26, a tracking drum and motor 28, and a controller unit 30. The tracking channel is located on the underside of the platform 12, centered about the pivot point 18 of the platform. The guide rollers are coupled to and rotated by the tracking drum and motor, and operatively engage the tracking channel to rotate the platform. In this instance, the guide rollers pull a continuous- loop wire rope or cable 36 that engages around the tracking channel to rotate the platform. The above-described arrangement is preferred for its high reliability and low cost, but those skilled in the art will recognize that many alternate arrangements are know suitable for and can be provided to rotate the platform about a pivot point. The controller unit 30 is programmed to power and rotate the motor and tracking drum 28 according to an algorithm appropriate for the geographic location and other applicable considerations of the installed tracking system, to rotate the platform and track the sun as it moves across the sky. The controller unit may operate on, for example, a relatively simple time-based algorithm, seasonally and geographically or otherwise adjusted, to rotate the platform in one direction, from a starting angular position to an ending angular position, during the daylight hours, and return the platform to the starting angular position when daylight hours are passed. A preferred controller unit includes light-intensity sensors 32 operable to enable implementation of a platform rotational control algorithm that precisely tracks the position of the sun and insures maximum incidence of solar radiation on the solar panels during daylight hours, and/or GPS module 34 to adjust the platform rotational control algorithm for the geographic location of the tracking system. This will insure maximum electric power output from the photovoltaic installation through the entire year and at any location in the world. The controller may also be programmed to adjust the angular position of the mirrors for enhanced performance purposes through controlled rotation of a positional drive connected to the pivotally mounted mirrors for powered adjustment of the position of the mirrors.

The rotating platform and tracking system of the invention can be used with pv solar panels, as well as other types of solar panels, solar collectors and other devices that will operationally benefit by tracking to the position of the sun.

Referring to FIGS. 8-10, there is shown a preferred alternate embodiment of a tracking system 50, accordance with the invention, which includes a single-axis rotating platform frame support structure 52 that carries rows (such as 4 rows that can be seen in the side view of FIG. 8) of photovoltaic (pv) solar panels 54, and power drive arrangement for purposes described above. In this instance, the platform 52 is supported in a horizontal position on a set of vertical supports and wheels 56, to rotate about a vertical axis "A2" through pivot point 58, and that travel around a durable circular track 60 such as embedded into a support structure (e.g., the ground). The pivot point is established by a rotatable platform support arrangement including a pivot shaft 62 supporting and extending downwardly from the underside of the platform and rotatably supported in bearings 64 in a bearing housing 66 resting on or secured to the ground or other support structure. The frame platform 52 includes frame members as pv beam supports 53 to support the rows of pv solar panels, and cross-frame and angled frame members 55 connected between the pv beam supports to establish a stable framework to support the pv panels.

In this preferred embodiment, the rows of solar panels 54 are equipped with corresponding performance enhancing booster mirrors 72 that focus additional solar radiation onto the panels. The rows of mirrors are mounted to pivot at horizontal axes "H2" so that the angle of the mirrors can be geographically, seasonally and otherwise adjusted for purposes described above, with angular positional drive connected to the rows of mirrors and the controller, and with the pv solar panels being electrically connected to an inverter or junction feeding an electrical power grid or electrical using device. The performance enhancing booster mirrors are low concentration aluminum composite material mirror which concentrate/reflect solar irradiance on to the pv modules and increase power output from the pv panels. As an example, in full phase reflection in a clear sunny day, the incident irradiation reaches up to 1300W/m2 (at peak hour).

From the foregoing, it will be apparent that the present invention brings to the art a new and unique rotating platform and tracking system for photovoltaic installations which is fully automatic, can be controlled by sensors and GPS to track the sun movement, can be provided with an efficient mechanical system and simple installation requirements. By virtue of the rotating platform and tracking system, the electrical output of solar panels is increased as compared with solar panels in a fixed position.

Industrial Applicability

Industrial applicability of the invention, the capability of exploitation in industry, and the way in which the invention can be made and used are fully described and/or obvious in view of the description above and the accompanying drawings.