CONCENTRATING SOLAR ENERGY SYSTEM WITH LIQUID FILLED LENS

Abstract

A solar photovoltaic system including a liquid filled lens configured to concentrate sunlight for the generation of electricity, desalination of water or production of steam. The liquid lens and receiver are mounted on a tracker. The complete system is lightweight and modular with multiple configurations possible. The liquid lens is manufactured using an improved method.

The use of a liquid lens for the purpose of collecting solar energy is novel.

Claims

1. A concentrating photovoltaic system comprising: a. a liquid filled lens comprising; i. two transparent thermoplastic surfaces; ii. filled with liquid; b. a photovoltaic cell positioned below the lens; c. a frame having multiple structural elements supporting the lens and receiving device; and d. a tracker system carrying the frame supporting the lens and receiving device and capable of orientating the lens to receive solar insolation.

2. The system of claim 1 wherein the liquid within the lens is glycerine.

3. The system of claim 1 wherein the two thermoplastic surfaces which form the lens contain multiple peaks and troughs such that one set of two surfaces may concentrate irradiance onto multiple photovoltaic cells.

4. The system of claim 1 wherein a light guide is positioned above the photovoltaic cell to direct insolation onto the photovoltaic cell.

5. A method for manufacturing a liquid filled lens, said method comprising: a. Providing two interlocking transparent thermoplastic surfaces b. Providing a vessel containing a liquid to be used as the filling between the two surfaces of sufficient volume to fully contain said interlocking surfaces c. Subjecting said two interlocking surfaces to immersion in the liquid to such a depth that they are fully submerged d. Bringing the two said interlocking surfaces together whilst they remain fully submerged e. Securing the two said interlocking surfaces together whilst they remain submerged

6. The manufacturing method of claim 5 wherein weldments are used in place of the segmented flange and bolt arrangement of claim 5e.

7. The manufacturing method of claim 5 wherein ultrasonic weldments are used in place of the segmented flange and bolt arrangement of claim 5e.

8. The manufacturing method of claim 5 wherein adhesive is used in place of the segmented flange and bolt arrangement of claim 5e.

9. The system of claim 1 wherein multiple photovoltaic cells are located on a single PCB.

10. The system of claim 1 wherein multiple photovoltaic cells are serviced by a single heatsink.

11. The system of claim 1 wherein the system is mounted on a tracker capable of orientating the lens arrangement(s) such that they receive optimal irradiance.

12. The system of claim 1 wherein the two surfaces which make up the lens are manufactured from glass.

13. The system of claim 1 wherein a working fluid being carried by a tube is used in place of a photovoltaic cell for the purpose of steam generation or water desalination.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The drawings contain the following components: [0011] 1. Thermoplastic lens casing [0012] 2. Clamping flange [0013] 3. Light guide tube [0014] 4. Photovoltaic cell [0015] 5. PCB for electrical wiring of the photovoltaic cell [0016] 6. Heat sink [0017] 7. Thermoplastic lens casing (TOP) [0018] 8. Thermoplastic lens casing (BOTTOM) [0019] 9. O-ring [0020] 10. Light transmissive liquid [0021] 11. Bolt [0022] 12. Vessel

[0023] The drawings are for illustrative purposes only and not to scale. In particular the curvature of the lens surface may be varied to achieve optimal transmission of insolation.

[0024] FIG. 1 is an exploded perspective view of the lens, optional light guide tube, cell assembly and optional heatsink.

[0025] FIG. 2 is a plan view of FIG. 1 showing one possible bolting configuration.

[0026] FIG. 3 is a side view of FIG. 2 showing one possible lens housing and coupling flange configuration.

[0027] FIGS. 4-7 are exploded perspective views of part of one possible manufacturing process for the lens assembly.

DESCRIPTION OF THE INVENTION

[0028] Referring to the drawings and FIG. 1 in particular, a liquid filled lens assembly is located above a light guide and photovoltaic cell. A frame may be used to hold the lens above the light guide and cell assembly.

[0029] The lens shown in FIG. 3 is comprised of two transparent thermoplastic surfaces which contain a liquid.

[0030] The formula describing the curvature of the thermoplastic surfaces will be governed by a number of factors including the distance of between the lens and the cell assembly as well as the refractive index of the liquid contained within the lens. The two surfaces may be dissimilar in profile.

[0031] The liquid contained within the transparent thermoplastic surfaces may be glycerol or another light transmissive liquid.

[0032] The two thermoplastic surfaces may be held together by a flange incorporating an O-ring. This arrangement forms a seal between the two surfaces which keeps the liquid inside the lens. Other methods of sealing could be used, including ultrasonic welding or an adhesive.

[0033] The photovoltaic cell can either be a single or triple junction silicon or gallium arsenide photovoltaic cell.

[0034] The cell is mounted on a PCB to form a cell assembly which transfers the electricity generated by the photovoltaic cell away from the cell. Optionally, the cell assembly may be mounted on a heat sink which transfers excess heat away from the photovoltaic cell.

[0035] Multiple cells may be mounted onto a single PCB and multiple cells or PCBs may be serviced by a single modular heatsink.

[0036] The lens, light guide, photovoltaic cell and heatsink may be held in their respective locations by a mounting frame.

[0037] Multiple lens and cell assemblies may be connected by wiring to form an array. An array will be mounted on a dual axis tracker. The tracker will be programmed to orientate the lens such that the direct insolation received by the array is maximised.

[0038] Multiple arrays may be connected in a single solar farm until the desired rated power output is reached.

[0039] The lens may be manufactured using the following method: [0040] 1. As shown in FIG. 4 parts for the lens assembly are fully submerged within the liquid vessel (12). [0041] 2. As shown in FIG. 5 the two lens surfaces (7, 8) are brought together such that the liquid completely fills the lens assembly. [0042] 3. The flange sections (2a-d) and O-ring (9) are brought together such that they clamp either side of the lens assembly (1). [0043] 4. The bolts (11) are used to secure the flange assembly in place. [0044] 5. The complete lens assembly (1,2) is removed from the liquid vessel (12).

[0045] Optionally, welding, ultrasonic welding, adhesive or other joining techniques may be used in place of bolts for step 4.