The present invention pertains to the field of encapsulating photovoltaic solar cells and in particular, to a method of encapsulating photovoltaic solar cells and producing modules suitable for paving surfaces that are able to support pedestrian and vehicle transportation.
Since middle 2000's there have been numerous attempts to use specially customized photovoltaic panels to pave road surfaces and so turn paved roads into a place for harvesting solar energy while retaining their traditional functions as a means of transportation and commuting.
All the prior art follows a similar approach to paving whereby a number of pre-fabricated photovoltaic panels or “modules” are used to either replace the upper layer of a conventional road surface or are paved directly upon existing road surfaces. Further all prior works follow the same principle for structural design whereby standard photovoltaic solar cells are sealed in a water-proof encapsulation with the top side of the module being transparent to allow penetration by incident sunlight. The uppermost side of the module must also: (1) be strong enough to withstand and protect the photovoltaic cells within from the loads and other mechanical stresses typically endured by roadways; and (2) provide a sufficient coefficient of friction implement an anti-skidding strategy to prevent pedestrians and vehicles from losing traction and causing accidents.
Therefore, there is a need for a superior method of encapsulating photovoltaic cells that ensures: complete protection from environmental and mechanical stresses, maximized photovoltaic conversion of photons to useful electricity; and sufficient coefficients of friction to minimize accidents.
This back-ground information is provided to reveal information believed by the applicant to be of possible relevance to the present invention. No admission is necessarily intended, nor should be construed, that any of the preceding information constitutes prior art against the present invention.
An object of the present invention is to provide a seamless encapsulation of photovoltaic modules for paving surfaces. In accordance with an aspect of the present invention, there is provided a method of manufacturing photovoltaic modules used for paving pedestrian or vehicle pathways comprised of: aligning one or more photovoltaic cells placed in a plane; seamlessly adhering a non-opaque, optical layer to the top surface and the side surfaces of the photovoltaic cells; and seamlessly adhering a mounting layer to the bottom of the photovoltaic cells and to the exposed bottom surfaces of the optical layer.
In accordance with another aspect of the present invention, there is provided a photovoltaic apparatus for paving pedestrian or vehicle pathways comprising: one or more photovoltaic cells placed in a plane; a non-opaque, optical layer seamlessly adhered to the top surface and the side surfaces of the photovoltaic cells; and a mounting layer seamlessly adhered to the bottom of the photovoltaic cells and to the exposed bottom surfaces of the optical layer.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.
The present invention provides a dual-element, seamless encapsulation process for packaging solar road modules that combines the advantages of using a first-element material for the sides and the bottom of the encapsulation and uses the second-element material when encapsulating the entirely of the module. The first-element material need not be the same as the second-element material allowing the top of the encapsulation to remain transparent while the bottom and the sides need not be so.
These two element protection layers are directly adhered to the photovoltaic cells from above and from below, forming a seamless encapsulation with one or a plurality of photovoltaic cells inside this encapsulation. The first (top) element, the photovoltaic cells themselves, and the second (bottom) element, are the core components of the present invention. Peripheral components include an anti-skidding layer (105) that is seamlessly adhered to the first element protection layer from above, and a baseplate (103) that resides underneath the second element layer and serves the functions of (1) integrating one or a plurality of encapsulations into one solar road module, and (2) interfacing the solar road module and the original road surface or the exposed road base. A binding layer (104) resides between the encapsulation and the baseplate serving the functions of (1) gluing the encapsulations to the baseplate and (2) offering a damping buffer that minimizes the propagation of vibrations throughout the apparatus.
The baseplate (103) is a rigid or flexible bed to host one (
A preferred embodiment of the present invention contemplates a four-step process of fabricating a complete solar road module. The required steps to fabricating the two-element seamless encapsulations are carried out in parallel with making the baseplate (103). There is no inherent interdependence between these two steps and so they may be assigned to two workshops to process in parallel.
An alternative embodiment of the invention is shown in
A fundamental nature of this invention is that the two element protective materials are characteristically different from above and from below the photovoltaic cells under protection, and that they should be seamlessly adhered to the photovoltaic cells. Essentially, the function of the first element protection layer from above (101) is to prevent the photovoltaic cells (100) from being damaged by loads on the road surfaces (pedestrians and vehicles) and to provide a transparent media for the incident sunlight to land on the photovoltaic cells, and the function of the second element protection layer from bottom (102) is to offer a pressure-conducting and strengthening layer to distribute mechanical forces uniformly to the layers underneath.
This design principle leads to two consequences: (1). it prescribes the criteria when choosing the best materials for the first element and for the second element, respectively. (2). the thickness of the first element and the second element need not be uniform, with the first element typically being thicker than the second. In a preferred embodiment, the empirical thickness of the first element ranges from 3 to 6 mm, whereas that of the second element ranges from 2 to 4 mm.
In a typical embodiment, a mold is employed in the three-step process of the two-element seamless encapsulation, as shown in
The baseplate (103) is the interface between the encapsulations and the original road surface or road base. One critical function of the baseplate is to ensure its good adhesion to the road surface or road base against possible displacement in horizontal directions under shearing stress caused by loads that move on the solar road. In order to provide such adhesion, the bottom of the baseplate 103 is prepared with textured patterns as shown in
When integrating the encapsulations with the baseplate, the binding layer (104) between the encapsulations and the baseplate not only adhesively secures the encapsulations with the baseplate, but also offers a damping buffer that minimizes the propagation of vibrations across multiple encapsulations and throughout the module. In typical embodiments, the materials for the binding layer can include polymers, silica gel, polyurethane, and organic materials with similar properties.
Anti-slip or anti-skidding is a basic and important requirement for any solar module used to pave road surfaces. In general, this requirement means enough surface friction on the road surface as result of pre-fabricated texture patterns or small artificial objects such as obstacles, bars, grooves, or gaps at various spatial scales and granularities. A preferred embodiment of the current invention employs a three-level anti-skidding strategy:
When forming a solar road module, the gaps between encapsulations establish a discontinuity at an interval length equal to the dimensions of the encapsulations. This periodic discontinuity, throughout the entire solar road pavement, forms a first level of anti-skidding patterns as illustrated in
Without any further processing, the top of each encapsulation will be smooth and devoid of anti-skidding characteristics. Thus, a preferred embodiment applies some micro-granularity level anti-skidding patterns to the top of each encapsulation. If the apparatus is fully covered with micro-granularity level anti-skidding patterns, will have a negative impact on the optical properties of the encapsulation. By coating only some areas with micro-granularity level anti-skidding patterns, we have created an intra-encapsulation level anti-skidding effect.
The anti-skidding patterns at the micro-granularity level consist of micro and randomly distributed surface structures on top of encapsulations to provide surface friction for the areas where these micro structures are applied. The granularity of these micro structures ranges from 0.5-2 mm and provide better the surface friction if they have randomly differing geometric shapes. There are two ways of realizing the micro-granularity anti-skidding layer:
As shown in
If the material for making the first element of the encapsulation is liquid-state before it freezes, then an alternative method for realizing micro-granularity anti-skidding patterns is shown in
As shown in
It will be understood that the foregoing embodiments of the invention are examples and can be varied in many ways. Such present or future variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.
Filing Document | Filing Date | Country | Kind |
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PCT/CA2018/050562 | 5/11/2018 | WO | 00 |
Number | Date | Country | |
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62505621 | May 2017 | US |