Multi-Element Concentrator System

• US 20110136020A1
• Filed: 10/06/2010
• Published: 06/09/2011
• Est. Priority Date: 06/09/2008
• Status: Active Grant

• Current Assignee: Fareed Sepehry-Fard, Mohammed Taghi Fatehi
• Original Assignee: Fareed Sepehry-Fard, Mohammed Taghi Fatehi
• Inventors: Fatehi, Mohammed Taghi, Sepehry-Fard, Fareed
• Granted Patent: US 8,110,786 B2
• Time in Patent Office: Days
• US Class Current: 429/400
• CPC Class Codes: F24S 2023/87 Reflectors layout
• CPC Class Codes: F24S 30/45 with two rotation axes
• CPC Class Codes: F24S 50/20 for tracking
• CPC Class Codes: G01S 3/7861 Solar tracking systems
• CPC Class Codes: H01L 31/0547 comprising light concentrating means of the reflecting type, e.g. parabolic mirrors, concentrators using total internal reflection
• CPC Class Codes: H02S 20/32 specially adapted for solar tracking
• CPC Class Codes: Y02E 10/47 Mountings or tracking
• CPC Class Codes: Y02E 10/52 PV systems with concentrators

Abstract

A novel concentrator system is described, which increases the efficiency of collecting and concentrating sunlight energy onto a target. This method uses an array of small movable reflective or refractive concentrator components that can move via a feedback mechanism which tracks the sun and concentrates the suns energy on to a second array of energy converting elements. In order to improve the effective collected energy, the array of concentrator elements is placed on a moving or tiltable flat slab (or dish, substrate, plane, plate, holder, tablet, or similar flat or non-flat surface) that tracks the sun. An alternative method uses an array of target elements or linear elements and a second array of concentrator elements in harmony such that the suns energy is efficiently redistributed by the reflective or refractive array on to the energy converting array as the sun'"'"'s position in the sky (elevation and azimuth) changes. The elements of the reflective or refractive array are tilted by novel actuation mechanisms describe herein.

Claims

1. A system for concentrating sunlight, said system comprising:

an array of reflective and/or refractive elements, each of said reflective and/or refractive elements comprising (i) a rigid slab comprising a conductive material that has a reflective and/or refractive top surface and (ii) a tilt mechanism that tilts said rigid slab, said tilt mechanism comprising an X-direction actuation mechanism and a Y-direction actuation mechanism;

at least two photodetectors located a distance from each other;

a differential tracker receiving signals from said photodetectors and generating a tracking signal related to or proportional to said signals from said photodetectors;

a tracking and control processor receiving said tracking signal from said differential tracker and controlling said tilt mechanisms such that said rigid slabs are tilted in the X-direction and the Y-direction in response thereto; and

a target that coverts sunlight to another form of energy, configured to absorb energy reflected from the reflective and/or refractive elements.

2. A system as recited in claim 1, wherein said tilt mechanism comprises a servo mechanism that moves said rigid slab using an electric motor or a step motor.

3. A system as recited in claim 1, wherein said tilt mechanism comprises (i) a hydraulic mechanism or (ii) a shape memory alloy that changes shape due to heat, current or other excitation.

4. A system as recited in claim 1, wherein said tilt mechanism comprises a feedback mechanism configured to align a vertical and/or horizontal axis of said system toward the sun.

5. A system as recited in claim 1, wherein said differential tracker is synchronized with an atomic clock, a GPS, and/or a database.

6. A system as recited in claim 1, wherein said control processor comprises a X-direction control processor and a Y-direction control processor.

7. A system as recited in claim 6, wherein:

said tracking and control processor generates a X-signal to said X-direction control processor and a Y-signal to said Y-direction control processor,

said X-direction control processor generates −

X and +X signals and feeds −

X and +X signals to said X-direction actuation mechanism, and

said Y-direction control processor generates −

Y and +Y signals and feeds said −

Y and +Y signals to said Y-direction actuation mechanism.

8. A system as recited in claim 1, wherein said target comprises an array of one- or two-dimensional point targets located at a predetermined distance above said array of reflective elements and/or below said refractive elements, wherein said reflective elements reflect and/or said refractive elements refract the sunlight on one or more of said array of point targets at any given instant in time.

9. A system as recited in claim 1, wherein said target comprises a solar cell, a fuel cell reactor, a photosynthesis element, or a fluid heating reservoir or pipe filled with running fluid and/or vapor.

10. A system as recited in claim 1, wherein said tilt mechanism further moves said rigid slab up and down in a third dimension along a z axis.

11. A system as recited in claim 1, further comprising a robot that cleans and/or sprays a surface of said reflective elements and/or said refractive elements.

12. A system as recited in claim 11, wherein said robot cleans and/or sprays the surface of said reflective elements and/or said refractive elements remotely and/or on-site locally through a sensor and/or a servo controller.

13. A system as recited in claim 1, wherein said system uses error correction codes or algorithms to steer, optimize, or align the reflective and/or refractive elements.

14. A method for concentrating sunlight, said system comprising:

detecting a difference in an angle of sun rays received by at least two photodetectors located a distance from each other;

generating a tracking signal related to or proportional to said difference in said angle of sun rays;

tilting an array of reflective or refractive elements in an X-direction and/or a Y-direction towards one or more targets using a tilt mechanism, each of said reflective elements being on a rigid slab, said tilt mechanism tilting said rigid slabs and comprising an X-direction actuation mechanism and a Y-direction actuation mechanism, said X-direction actuation mechanism and said Y-direction actuation mechanism being responsive to said tracking signal; and

converting sunlight to another form of energy using said one or more targets.

15. A method as recited in claim 14, wherein said tilt mechanism further comprises a Z-direction actuation mechanism that moves the rigid slabs up and down in a third dimension along a z axis.

16. A method as recited in claim 14, wherein said tilt mechanism comprises a servo mechanism that moves said rigid slab using an electric motor or a step motor.

17. A method as recited in claim 14, wherein said tilt mechanism comprises (i) a hydraulic mechanism or (ii) a shape memory alloy that changes shape in response to application of heat, current or other excitation.

18. A method as recited in claim 17, wherein said tilt mechanism comprises a feedback mechanism to align said reflective and/or refractive elements toward the sun.

19. A method as recited in claim 14, further comprising synchronizing tilting said rigid slabs using an atomic clock, GPS, and/or database.

20. A method as recited in claim 14, wherein tilting said reflective elements comprises moving said rigid slabs in said X-direction and said Y-direction to a desired angle using a differential electrostatic force under feedback control.