US20130025583A1

US20130025583A1 - Solar tracking system

Info

Publication number: US20130025583A1
Application number: US13/191,452
Authority: US
Inventors: Wong Kenneth TAM
Original assignee: Du Pont Apollo Ltd
Current assignee: Du Pont Apollo Ltd
Priority date: 2011-07-27
Filing date: 2011-07-27
Publication date: 2013-01-31

Abstract

Disclosed herein is a solar tracking system. The solar collector has a first end and a second end. The fulcrum is located between the first end and the second end of the solar collector. The solar collector revolves eastward or westward about the fulcrum. The water container is attached to the first end of the solar collector and has a water inlet and a water outlet valve. The first resilient member is secured to and supports an underside of the first end or second end of the solar collector. The first trigger switch is used to detect if the water container is empty of water to open the water input valve to supply water and close the water outlet valve. The second trigger switch is used to detect if the water container is full of water to close the water input valve and open the water outlet valve to drain water out of the water container.

Description

BACKGROUND

1. Field of Invention
The present invention relates to a solar tracking system and, more particularly, to a solar tracking system including a solar energy collector.
2. Description of Related Art
Photovoltaic devices are most efficient when the incident light is perpendicular to the device. Stationary photovoltaic devices do not operate at optimal efficiency because the sun moves across the sky throughout the day.
A conventional heliostat type solar tracker for a solar energy system, e.g. a photovoltaic device, is configured to slowly revolve by means of a motor. In a conventional solar energy system capable of generating 1 KW of power, its solar module has a weight of about 10 Kg. The solar module and other cooperating components, e.g. a supporter, may have a total weight of more than 100 Kg. Also, a solar collector is quite heavy. Thus, the revolving of the solar energy system by a motor may disadvantageously consume much energy and increase cost. This is not desired. Thus, a need for improvement exists.

SUMMARY

It is therefore an objective of the present invention to provide an improved solar tracking system.
In accordance with the foregoing and other objectives of the present invention, a solar tracking system includes a solar collector, a fulcrum, a water container, a first resilient member, a water supply, a first trigger switch and a second trigger switch. The solar collector has a first end and a second end. The fulcrum is located between the first end and the second end of the solar collector. The solar collector revolves eastward or westward about the fulcrum. The water container is attached to the first end of the solar collector and has a water inlet and a water outlet valve. The first resilient member is secured to and supports an underside of the first end of the solar collector, with the first resilient member compressing when the solar collector pivots about the fulcrum with the first end moving down and the second end moving up. The water supply is used to input water into the water inlet of the water container. The first trigger switch is used to detect if the water container is moved upward to a position indicating that the water container is empty of water so as to open the water input valve to supply water and close the water outlet valve. The second trigger switch is used to detect if the water container is moved downward to a position indicating that the water container is full of water so as to close the water input valve and open the water outlet valve to drain water out of the water container.
In another embodiment disclosed herein, the first resilient member is a compression spring.
In another embodiment disclosed herein, the solar tracking system further includes a water receiving inlet for collecting the water from the water outlet valve.
In another embodiment disclosed herein, the solar tracking system further includes a wire, chain, rope or cable interconnected between the water container and the first end of the solar collector.
In another embodiment disclosed herein, the solar tracking system further includes a support member, and the fulcrum is pivoted on a top end of the support member.
In another embodiment disclosed herein, the solar tracking system further includes a second resilient member secured to and supporting an underside of the second end of the solar collector, with the second resilient member extending as the solar collector pivots about the fulcrum with the first end moving down and the second end moving up.
In another embodiment disclosed herein, the second resilient member is an extension spring.
In another embodiment disclosed herein, the water supply includes a water input valve.
In accordance with the foregoing and other objectives of the present invention, a solar tracking system includes a solar collector, a fulcrum, a water container, a first resilient member, a water supply, a first trigger switch and a second trigger switch. The solar collector has a first end and a second end. The fulcrum is located between the first end and the second end of the solar collector. The solar collector revolves eastward or westward about the fulcrum. The water container is attached to the first end of the solar collector and has a water inlet and a water outlet valve. The first resilient member is secured to and supports an underside of the second end of the solar collector, with the first resilient member extending when the solar collector pivots about the fulcrum with the first end moving down and the second end moving up. The water supply is used to input water into the water inlet of the water container. The first trigger switch is used to detect if the water container is empty of water so as to open the water input valve to supply water and close the water outlet valve. The second trigger switch is used to detect if the water container is full of water so as to close the water input valve and open the water outlet valve to drain water out of the water container:
In another embodiment disclosed herein, the first resilient member is an extension spring.
In another embodiment disclosed herein, the solar tracking system further includes a water receiving inlet for collecting the water from the water outlet valve.
In another embodiment disclosed herein, the solar tracking system further includes a wire, chain, rope or cable interconnected between the water container and the first end of the solar collector.
In another embodiment disclosed herein, the solar tracking system further includes a support member, and the fulcrum is pivoted on a top end of the support member.
In another embodiment disclosed herein, the solar tracking system further includes a second resilient member secured to and supporting an underside of the first end of the solar collector, with the first resilient member compressing as the solar collector pivots about the fulcrum with the first end moving down and the second end moving up.
In another embodiment disclosed herein, the second resilient member is a compression spring.
In another embodiment disclosed herein, the water supply includes a water input valve.
Thus, the solar tracking system disclosed herein fills only one water container throughout the day time and drains it out continuously during the night time. This forgoes the need of a clockwork mechanism or an angle measurement device as found in a conventional solar tracking system. The flow of water is controlled by valves triggered by the trigger switches only twice a day when the water container is either full or empty. This leads to a simpler overall system in line with the purpose of providing a cheap solar tracking system. The water container disclosed herein is also attached under the solar collector via a wire as opposed to mounted above the solar collector in the conventional solar tracking system. This allows the water tank providing the water to the container to be placed below solar collector, avoiding any shadowing effects on the solar collector as the sun moves across the sky.
It is to be understood that both the foregoing general description and the following detailed description are by examples, and are intended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. In the drawings,

FIG. 1 illustrates a solar tracking system according to a first embodiment of this invention; and

FIG. 2 illustrates another solar tracking system according to a second embodiment of this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference will now be made in detail to the present preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts.
FIG. 1 illustrates a solar tracking system 100 according to a first embodiment of this invention. The solar tracking system 100 includes a solar collector 101, e.g. a photovoltaic device, to revolve and track the sun 150. The solar collector 101 has a fulcrum 101 a, located between its first end 101 b and second end 101 c. The fulcrum 101 a is preferably, but is not limited to being, located at a middle point (of the solar collector 101) between the first end 101 b and the second end 101 c. In this embodiment, the fulcrum 101 a can be pivoted on a top end 105 of a support member 104, which is secured to a floor 106, e.g., a roof floor.
A resilient member 102 and a water container 110 are utilized to drive the solar collector 101 to revolve. The water container 110 is mounted at the first end 101 b of the solar collector 101. The water container 110 can be mounted at the first end 101 b of the solar collector 101 directly or with a wire, chain, rope or cable 107, i.e., the wire, chain, rope or cable 107 is interconnected between the water container 110 and the first end 101 b of the solar collector 101. The resilient member 102 is secured to and supports an underside of the second end 101 c of the solar collector 101, with the resilient member 102 extending when the solar collector 101 pivots about the fulcrum 101 a with the first end 101 b moving down and the second end 101 c moving up (as illustrated in FIG. 1). In this embodiment, the resilient member 102 can be an extension spring.
The water container 110 has a water inlet 116 and a water outlet valve 129. The water inlet 116 is used to receive water from a water supply 126. When the water container 110 receives water from the water supply 126 and becomes heavier, the solar collector 101 revolves clockwise, i.e., in a westward direction. When the water container 110 is draining water and becomes lighter, the solar collector 101 revolves counter-clockwise, i.e., in an eastward direction.
The water supply 126 has a water input valve 128 to regulate the rate at which water flows into the water container 110 from the water supply 126 (hereinafter referred to as “the water-supply flow rate”). The water-supply flow rate regulated by the water input valve 128 is preferably adjusted to a constant rate to enable the water container 110 to drive the solar collector 101 (against the force exerted by the resilient member 102) to revolve at a constant angle speed. Therefore, the solar collector 101 is able to track the sun 150 from east to the west throughout the day time.
The water outlet valve 129 of the water container 110 is used to regulate the rate at which water is drained from the water container 110 (hereinafter referred to as “the water-draining flow rate”). The water-draining flow rate regulated by the water outlet valve 129 is preferably adjusted to a constant rate to reduce the weight of the water container 110 such that the resilient member 102 can drive, i.e., pull, the solar collector 101 to revolve at a constant angle speed. During the night time, the solar collector 101 does not track the sun. Therefore, the water-draining flow rate of the water container 110 can be greater than the water-supply flow rate of the water supply 126 such that the solar collector 101 can faster return back to a starting point for tracking the sun in the morning.
A trigger switch 114 is used to detect if the water container 110 is full of water so as to close the water input valve 128 and open the water outlet valve 129 to drain water out of the water container 110. The trigger switch 114 maybe located, but is not limited to being located, at an upper position within the water container 110.
A trigger switch 112 is used to detect if the water container 110 is empty of water so as to open the water input valve 128 to supply water and close the water outlet valve 129. The trigger switch 112 maybe located, but is not limited to being located, at a bottom within the water container 110.
A water receiving inlet 127 is used to collect the water from the water outlet valve 129 of the water container 110. The water supply 126 and the water receiving inlet 127 can be both connected to a water pipe 122, which is connected to a water tank 120 at a higher level. Thus, the water used to operate the solar tracking system 100 can be returned back to its original water supply system within one day and no water is wasted.
FIG. 2 illustrates a solar tracking system 200 according to a second embodiment of this invention. The solar tracking system 200 is different from the solar tracking system 100 with respect to the positioning of the resilient member and the trigger switch. The solar tracking system 200 includes a solar collector 201, e.g. a photovoltaic device, to revolve and track the sun 250. The solar collector 201 has a fulcrum 201 a, located between its first end 201 b and second end 201 c. The fulcrum 201 a is preferably, but is not limited to being, located at a middle point (of the solar collector 201) between the first end 201 b and the second end 201 c. In this embodiment, the fulcrum 201 a can be pivoted on a top end 205 of a support member 204, which is secured to a floor 206, e.g., a roof floor.
A resilient member 202 and a water container 210 are utilized to drive the solar collector 201 to revolve. The water container 210 is mounted at the first end 201 b of the solar collector 201. The water container 210 can be mounted at the first end 201 b of the solar collector 201 directly or with a wire, chain, rope or cable 207, i.e., the wire, chain, rope or cable 207 is interconnected between the water container 210 and the first end 201 b of the solar collector 201. The resilient member 202 is secured to and supports an underside of the first end 201 b of the solar collector 201, with the resilient member 202 compressing when the solar collector 201 pivots about the fulcrum 201 a with the first end 201 b moving down and the second end 201 c moving up (as illustrated in FIG. 2). The resilient member 202 can be a compression spring.
The water container 210 has a water inlet 216 and a water outlet valve 229. The water inlet 216 is used to receive water from a water supply 226. When the water container 210 receives water from the water supply 226 and becomes heavier, the solar collector 201 revolves clockwise, i.e., in a westward direction. When the water container 210 is draining water and becomes lighter, the solar collector 201 revolves counter clockwise, i.e., in an eastward direction.
The water supply 226 has a water input valve 228 to regulate the rate at which water flows into the water container 210 from the water supply 226 (hereinafter referred to as “the water-supply flow rate”). The water-supply flow rate regulated by the water input valve 228 is preferably adjusted to a constant rate to enable the water container 210 to drive the solar collector 201 (against the force exerted by the resilient member 202) to revolve at a constant angle speed. Therefore, the solar collector 201 is able to track the sun 250 from east to west throughout the day.
The water outlet valve 229 of the water container 210 is used to regulate the rate at which water is drained from the water container 210 (hereinafter referred to as “the water-draining flow rate”). The water-draining flow rate regulated by the water outlet valve 129 is preferably adjusted to a constant rate to reduce the weight of the water container 210 such that the resilient member 202 can drive the solar collector 201 to revolve at a constant angle speed. During the night, the solar collector 201 does not track the sun. Therefore, the water-draining flow rate of the water container 210 can be greater than the water-supply flow rate of the water supply 226 such that the solar collector 201 returns back to a starting point for tracking the sun in the morning.
A trigger switch 214 is used to detect if the water container 210 is moved upward to a position indicating that the water container is empty of water so as to open the water input valve 228 to supply water and close the water outlet valve 229. The trigger switch 214 may be located on, but is not limited to being on, the water supply 226.
A trigger switch 212 is used to detect if the water container 210 is moved downward to a position indicating that the water container is full of water so as to close the water input valve 228 and open the water outlet valve 229 to drain water out of the water container 210. The trigger switch 212 may be located on, but is not limited to being on, a water receiving inlet 227.
The water receiving inlet 227 is used to collect the water from the water outlet valve 229 of the water container 210. The water supply 226 and the water receiving inlet 227 can be both connected to a water pipe 222, which is connected to a water tank 220 at a higher level. Thus, the water used to operate the solar tracking system 200 can be returned back to its original water supply system within one day and no water is wasted. The water supply system can be a water tank/pump system with the main function of providing everyday water use to the household or a business building.
In the solar tracking system 100 of FIG. 1, another resilient member, e.g. a resilient member 202, can be secured to and supports an underside of the first end 101 b of the solar collector 101 if the resilient member 102 does not provide enough force to balance a larger water container.
Similarly, in the solar tracking system 200 of FIG. 2, another resilient member, e.g. a resilient member 102, can be secured to and supports an underside of the second end 201 c of the solar collector 201 if the resilient member 202 does not provide enough force to balance a larger water container.
According to the above-discussed embodiments, the solar tracking system disclosed herein fills only one water container throughout the day time and drains it out continuously during the night time. This forgoes the need of a clockwork mechanism or an angle measurement device as found in a conventional solar tracking system. The flow of water is controlled by valves triggered by the trigger switches only twice a day when the water container is either full or empty. This leads to a simpler overall system in line with the purpose of providing a cheap solar tracking system. The water container disclosed herein is also attached under the solar collector via a wire as opposed to mounted above the solar collector in the conventional solar tracking system. This allows the water tank providing the water to the container to be placed below solar collector, avoiding any shadowing effects on the solar collector as the sun moves across the sky.
It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the present invention cover modifications and variations of this invention provided they fall within the scope of the following claims and their equivalents.

Claims

1. A solar tracking system comprising:

a solar collector having a first end and a second end;

a fulcrum located between the first end and the second end of the solar collector, and about which the solar collector revolves eastward or westward;

a water container attached to the first end of the solar collector and having a water inlet and a water outlet valve;

a first resilient member secured to and supporting an underside of the first end of the solar collector, with the first resilient member compressing when the solar collector pivots about the fulcrum with the first end moving down and the second end moving up;

a water supply for inputting water into the water inlet of the water container;

a first trigger switch for detecting if the water container is moved upward to a position indicating that the water container is empty of water so as to open the water input valve to supply water and close the water outlet valve; and

a second trigger switch for detecting if the water container is moved downward to a position indicating that the water container is full of water so as to close the water input valve and open the water outlet valve to drain water out of the water container.

2. The solar tracking system of claim 1, wherein the first resilient member is a compression spring.

3. The solar tracking system of claim 1, further comprising a water receiving inlet for collecting the water from the water outlet valve.

4. The solar tracking system of claim 1, further comprising a wire, chain, rope or cable interconnected between the water container and the first end of the solar collector.

5. The solar tracking system of claim 1, further comprising a support member, and the fulcrum is pivoted on a top end of the support member.

6. The solar tracking system of claim 1, further comprising a second resilient member secured to and supporting an underside of the second end of the solar collector, with the second resilient member extending as the solar collector pivots about the fulcrum with the first end moving down and the second end moving up.

7. The solar tracking system of claim 6, wherein the second resilient member is an extension spring.

8. The solar tracking system of claim 1, wherein the water supply comprises a water input valve.

9. A solar tracking system comprising:

a solar collector having a first end and a second end;

a first resilient member secured to and supporting an underside of the second end of the solar collector, with the first resilient member extending when the solar collector pivots about the fulcrum with the first end moving down and the second end moving up;

a water supply for inputting water into the water inlet of the water container;

a first trigger switch for detecting if the water container is empty of water so as to open the water input valve to supply water and close the water outlet valve; and

a second trigger switch for detecting if the water container is full of water so as to close the water input valve and open the water outlet valve to drain water out of the water container.

10. The solar tracking system of claim 9, wherein the first resilient member is an extension spring.

11. The solar tracking system of claim 9, further comprising a water receiving inlet for collecting the water from the water outlet valve.

12. The solar tracking system of claim 9, further comprising a wire, chain, rope or cable interconnected between the water container and the first end of the solar collector.

13. The solar tracking system of claim 9, further comprising a support member, and the fulcrum is pivoted to a top end of the support member.

14. The solar tracking system of claim 9, further comprising a second resilient member secured to and supporting an underside of the first end of the solar collector, with the first resilient member compressing as the solar collector pivots about the fulcrum with the first end moving down and the second end moving up.

15. The solar tracking system of claim 14, wherein the second resilient member is a compression spring.

16. The solar tracking system of claim 11, wherein the water supply comprises a water input valve.