Lightweight cellular photovoltaic modules.

Abstract

A design approach for lightweight, specific photovoltaic modules using multi-walled panels, for example, made of polycarbonate. These multi-walled panels are already in use and readily available. They are both lightweight and rigid, meeting the technical specifications of this specific application. This innovation will open up new possibilities and new installation methods, thus contributing to the wider deployment of this renewable energy source.

Description

Title of the invention: Lightweight honeycomb photovoltaic modules. technical field

[0001] The present invention relates to a specific design of lightweight photovoltaic modules which allows new fields of use, new installation methods and which thus contributes to a wider deployment of these renewable energy generators. Previous technique

[0002] Photovoltaic modules, or photovoltaic solar panels, are designed to generate a direct current when exposed to sunlight. They typically consist of a transparent front face made of glass or polymer materials, allowing maximum light transmission. At the core of the modules are the photovoltaic reactive elements encapsulated in a polymer material, all connected by electrical connections leading to a junction box that provides the output of the electrical cables. On the back side is an insulating material, most often made of polymer; the whole forming a photovoltaic "laminate".

[0003] To ensure the stability, rigidity, and strength of the laminate, two main design approaches are distinguished: Either these laminates are surrounded by a robust frame, most often made of aluminum, or, less commonly, they can be designed for use without a frame. In this specific case, they are intended to be bonded directly to a substrate sufficiently rigid to guarantee their mechanical resistance (for example, on roofing or building facade elements).

[0004] All photovoltaic modules are designed to ensure good performance over the years. They have physical and mechanical electrical specifications that comply with applicable standards (such as IEC-61215 or IEC-61730). This standard framework typically includes minimum requirements for resistance to environmental stresses such as wind, snow, hail, moisture ingress, heat, and shock, as well as safety requirements, particularly regarding electrical components. All of these factors influence the materials, component dimensions, and design options chosen by module manufacturers.

[0005] These requirements also impose constraints on the installation of the modules with various mounting systems or structures; constraints also in terms of weight, total load on the device, and possibly also on the installation structure. All of this can complicate, limit, or even preclude the installation of photovoltaic systems.

[0006] Thus, manufacturers of photovoltaic modules are seeking solutions for lighter and more economical systems. This must be done while guaranteeing satisfactory levels of robustness, ease of handling, and durability. The solutions considered must remain competitive and, if possible, offer a reduced carbon footprint and a high recyclability rate. Brief description of the drawings

[0007] Here is the list of diagrams and illustrations located at the end of the document.

[0008] Legend:

[0009] 1: Photovoltaic laminate

[0010] 2: Part of the photovoltaic module consisting of a honeycomb plate

[0011] - Fig. 1 is a simplified diagram representing a photovoltaic module. lightened veolar view from the front then in lateral section.

[0012] - Figure 2 shows four examples of alveolar plates with different thicknesses, structures and geometries of internal walls. The view is a cross-section of these four sample plates.

[0013] - Fig. 3 is a simplified diagram that represents a variation of the concept with the photovoltaic laminate arranged in portrait mode relative to the ventilation tunnels of the honeycomb plate.

[0014] - Fig. 4 is a simplified diagram that represents a variation of the concept with 3 Photovoltaic laminates arranged on a larger honeycomb plate.

[0015] - Fig. 5 is a simplified diagram that represents a variation of the concept with a photovoltaic laminate placed on each side of the honeycomb plate support. Summary of the invention

[0016] Here we develop the design of a photovoltaic module by bonding or gluing the photovoltaic laminate onto a rigid polymer sheet substrate with a honeycomb geometric structure, which we call a "honeycomb sheet." The type of polymer chosen for these honeycomb sheets can, for example, be made of polycarbonate (PC), PMMA, PVC, polyethylene (PE or HDPE), polystyrene (PS), or polypropylene (PP). If possible, it could be based on biomaterials or bio-based materials. A combination of several polymer materials can also be considered.

[0017] The concept of this innovation lies in associating, or bonding, one or more photovoltaic laminates onto a honeycomb panel. This panel is honeycomb in its design and geometry, but not in its physical structure, insofar as its thickness is composed of several geometrically arranged voids. These voids or air passages are very useful in this innovation because the photovoltaic laminates perform better if some form of ventilation limits their heating. Therefore, the arrangement of the Photovoltaic laminates in relation to the orientation of the ventilation tubes will be determined according to the applications and installation methods.

[0018] Honeycomb panels are already used in the construction of roofs and facades. They are known for their resistance to weathering and their durability. The most commonly used honeycomb panels are made of polycarbonate and are also available in various thicknesses, geometries, and interlocking or fixing systems using different profiles.

[0019] Decisions on the material(s) used, the thickness of the plates, their geometries, their tints or their degrees of transparency will be made according to the applications and the properties sought, depending on the objectives of resistance, rigidity, bulk, aesthetic criteria, also depending on the costs.

[0020] Description of the elements of the photovoltaic module thus designed:

[0021] A photovoltaic module consists of a part called a "photovoltaic laminate" because they are most often assembled using a lamination technique combining heat and vacuum. On the front or outer face exposed to solar radiation, these laminates consist of a transparent layer of varying thickness made of glass or polymer / composite materials. Under this protective layer are the photovoltaic sensing part and the electrical connections encapsulated in a suitable material such as EVA. This active part can be made using various technologies, employing photoreactive semiconductor materials of all types: silicon (c-Si) cells, active layers based on CIGS, CDTE, perovskite, OPV, etc. The electrical connections within the laminates can be of all types or configurations. They run to junction boxes from which the electrical cables extend outside the modules.The back face is typically made of an insulating and protective film of synthetic material often based on Tedlar (TPT, TPA, but also APA, PO, KPE, PVDF-PET-EVA etc).

[0022] It is on this rear face of the photovoltaic laminates that we attach, by gluing, heat bonding, or heat welding, the honeycomb panel to form the module support. This panel can be of various dimensions and structures depending on the intended use. Numerous adhesive formulas have been tested and proven on these materials. It will be easy to choose the most suitable ones according to the requirements. Transparent adhesives are also available.

[0023] Later, after carrying out studies and tests, an alternative assembly method will be to consider using the honeycomb plate directly as the rear insulation face of the photovoltaic laminates.

[0024] The connection boxes, from which the electrical cables originate outside the photovoltaic laminates, can, at will, be placed on the front face of the photovoltaic laminates, or on the rear face by cutting the honeycomb plate.

[0025] These photovoltaic modules, which we call "Lightweight cellular photovoltaic modules", will have to pass the tests and certifications in force before their marketing and installation. Advantages of the process:

[0026] Several advantages result from the implementation of this innovative design and the use of honeycomb panels for these photovoltaic modules:

[0027] These modules exhibit good mechanical strength, rigidity, and impact resistance, which advantageously eliminates the need for a peripheral frame. Rigidity is adjustable depending on the plates used and their specifications, particularly thickness and structure. Therefore, it is also possible to reduce the thickness of the transparent front protective face, whether glass or polymer / composite, and further reduce weight while maintaining sufficient impact resistance, especially against hail. This results in lighter and potentially smaller photovoltaic modules.

[0028] The characteristic of the honeycomb panels is that they are naturally ventilated by the multiple air tunnels that compose them. This natural ventilation is useful for cooling the photovoltaic laminates, whose performance decreases as their temperatures increase.

[0029] Honeycomb panels have been used for several decades as building roofing elements. The modules thus designed will therefore easily be able to perform this roofing and waterproofing function while adding the function of photovoltaic generators.

[0030] Honeycomb panels can offer high transparency, which is very useful when there is a need for light in the heart of buildings, but also when using double-sided laminates which have the characteristics of transforming light radiation into electrical current via the front face but also via the back face.

[0031] This design can also be implemented in a bifacial module configuration by adding a laminate to each side of the honeycomb panel. In this specific case, the honeycomb panel between two laminates no longer constitutes the rear face of the module but its central part. This configuration is ideal for use in an agricultural setting with rows or lines of photovoltaic modules arranged vertically and oriented towards the East and West, leaving the area free for machinery and for crops or pastures.

[0032] These cellular panels are known for their durability and resistance to climatic hazards. Following numerous product developments and feedback from experience in building applications, they are installed using a wide range of proven installation techniques. For example, there are many... Peripheral mounting accessories, such as specially adapted profiles and interlocking systems for connecting panels, are essential. Beyond simply installing and securing the modules, these accessories can easily accommodate and hold electrical cables and cable trays in place, whether on the front or back of the photovoltaic modules. Proper cable management and long-term maintenance are crucial for all photovoltaic systems. Non-exhaustive examples of implementation:

[0033] Below is a list of contexts for the installation of photovoltaic systems for which this innovation may provide a satisfactory solution.

[0034] In the case of building roofing, the existing roof can simply be replaced by a roof made of cellular modules. These will provide a reliable, current-generating roof, and will also offer, as an option, a degree of transparency to this new roof.

[0035] In cases of building roofs that cannot accept heavy additional loads, these lightweight modules will be able to provide a solution to the overload challenge.

[0036] In the case of ground-mounted photovoltaic power plants installed on dedicated mounting structures, the modules designed in this way can replace the use of conventional modules with their aluminum frames. This will result in savings on production costs and potentially also on the carbon and energy balances of the installation. Furthermore, in the context of a mixed activity combining agriculture and energy production, also known as "agrivoltaics," these modules can be advantageously arranged vertically in their bifacial configuration for ideal East-West dual exposure, a highly sought-after feature by market players.

Claims

Claims

1. Design of photovoltaic modules for which one or more photovoltaic laminates, whatever their photovoltaic technology, are associated by gluing, heat-bonding or heat welding, on a support plate made of cellular polymer also called a cellular plate, which is characterized by the fact that the photovoltaic laminate(s) are thus mechanically supported on their rear face and no longer only on the periphery. These cellular plates can be made of polymers such as, for example, polycarbonate PC, PMMA, PVC, polyethylene PE or HDPE, polystyrene PS, polypropylene PP. If possible, all or part of the material may be made of biomaterials or biosourced materials. A combination of several polymer materials can also be envisaged.

2. Design of photovoltaic modules according to claim 1, for which the two faces of the honeycomb plate are covered with one or more photovoltaic laminates to constitute a double-sided photovoltaic module with double exposure.

Images