EP4460666A2

EP4460666A2 - A solar mirror

Info

Publication number: EP4460666A2
Application number: EP22919131.7A
Authority: EP
Inventors: Halide Gulsah KAHRAMAN; Gurkan YIGITER; Zeynep AYDIN; Gurkan VARDAR; Erdem YILDIRIM
Original assignee: Tuerkiye Sise Ve Cam Fabrikalari AS
Current assignee: Tuerkiye Sise Ve Cam Fabrikalari AS
Priority date: 2022-01-07
Filing date: 2022-11-03
Publication date: 2024-11-13

Abstract

The present invention relates to a solar mirror (1) with increased durability, which reflects the incoming light and focuses it on a fixed receiver, especially in concentrated solar energy farms that produce energy with solar energy, indoors, and in the defense industry.

Description

A SOLAR MIRROR

Technical Field

The present invention relates to a solar mirror with increased durability, used in concentrated solar power plants to direct the incoming sunlight to the receiver surface.

Prior Art

Mirrors are used especially in architectural applications, furniture, building facades, interior decoration, showcases, medical sector, automotive sector for decoration or to reflect the image. Solar mirrors are used in concentrated solar power plants to direct the incoming sunlight to the receiver surface. Solar mirrors are formed from a metallic layer deposited (coated) on a glass sheet and other layers that protect this layer from external exposures. The reflective property of the mirror is provided by using a reflective layer made of metallic materials. The layers in question are usually metals having high reflectivity, such as silver or aluminum.

Solar mirrors are used in concentrated solar power plants. Concentrated solar energy systems are based on reflecting the sun light falling on a large area to a relatively small area by means of mirrors and sun tracking systems connected to these mirrors. Sun light is reflected with the help of solar mirrors located in a certain area and focus on the receiver at a fixed point. In this way, it is ensured that the light from the sun is used efficiently for energy production. To ensure efficient transmission of incoming light, solar mirrors are expected to have high energy reflectance value.. Solar farms are usually located outside of cities, in open space, open to the atmosphere. The reflective layers of the mirrors are made of metallic materials such as silver and aluminum. Metals naturally corrode. Humidity and other environmental/atmospheric influences affect the rate of metal corrosion. Corrosion and damage to the metallic layer in the mirrors causes the reflectance values of the mirror to decrease, and its efficiency and service life to decrease. The decrease in the efficiency of solar mirrors also causes a decrease in the amount of energy to be produced. For this reason, it is extremely important to increase the corrosion resistance of the metallic layer of solar mirrors used in the solar energy sector. In solar mirror applications, the reflective metal layer is protected from the top and bottom against outdoor conditions due to its sensitivity to wear and corrosion.

Solar mirrors are generally used in areas far from residential areas. This situation causes the maintenance, repair and replacement of solar mirrors to be costly. It is very important that solar mirrors gain resistance to outdoor conditions. Solar mirrors are especially used in solar power plants located in hot regions and deserts where the sunshine duration is long. In these environments, wind, sandstorms, day- night temperature difference and similar external factors damage solar mirrors.

Wear status of solar mirrors used in energy generation application is frequently observed. In the said application, mirrors are used especially open to the atmosphere. Exposure of the mirror to the external environment allows the mirror to be abraded due to environmental external factors. In addition, gases and pollution-producing materials in the atmosphere cause the wear of the mirrors used in the said application. Abrasion of the mirror causes the mirror to lose its reflective property. This wear causes the product to become unusable.

In solar mirror applications, mirrors with reflective properties are used by depositing metal on the glass. In this application, metal is deposited on one surface of the glass. Protective paint is applied on the metallic layer to protect the metallic layer against external exposures. In this protective paint application, paints consisting of an organic -based resin and an inorganic filler material are generally used. The content of paints can be water-based or solvent-based. Protective paints can be applied in different numbers of coats depending on their content, such as single coat, double coat, triple coat.

In an embodiment in the state of the art, copper plating is used to protect the metallic layer in solar mirrors. Lead-containing primer paints are used to increase the corrosion resistance of the said copper coating. The lead contained in primer paints is harmful to the environment and therefore, it is aimed to use lead-free clean materials.

In another prior art embodiment, alkyd-melamine resin is used to increase the durability of solar mirrors. The said resin protects indoor mirrors in indoor conditions. Outdoor resistance of solar mirrors protected with alkyd-melamine based paint is insufficient, especially for concentrated solar power plants.

As explained above, it is quite possible for the mirrors to corrode in indoor and outdoor conditions. In the state of the art, in order to prevent corrosion of the mirror, the metallic layer component of the mirror is protected by a glass sheet on the one hand, and protected by a protective paint on the other. Although these paints meet the expectations of durability in indoor conditions, they are inefficient in outdoor environments. Embodiments in the state of the art are inefficient in terms of cost. In addition, paint systems used to protect the copper layer and increase its effectiveness in embodiments where the reflective layer is protected with copper in the state of the art contain lead. Lead is a material that harms nature.

In the present invention, a solar mirror with increased durability is realized with alkyd-melamine in the case of copper; polyester-based primer in the case without a copper layer; and with the use of a polyurethane-based protective topcoat in both cases. Objects of the Invention

The object of the present invention is to realize a solar mirror in which its reflective layer is preferably protected by two layers of protective paint.

Another object of the present invention is to realize a solar mirror in which the metallic coating is protected with an alkyd-melamine based protective primer in applications where copper is used to protect the metallic layer of the mirror.

Another object of the present invention is to realize a solar mirror in which the metallic layer is protected with a polyester-based protective primer in applications where copper is not used to protect the metallic layer of the mirror.

Another object of the present invention is to increase the exterior resistance of the mirror by applying a polyurethane-based topcoat paint on the primer paint in both cases where copper is used and not used to protect the metallic layer of the mirror.

Brief Description of the Invention

The present invention is particularly suitable for use as solar tracking mirrors (solar mirrors) in concentrated solar power plants to reflect the sun light.

A solar mirror, as defined in the first claim and the other claims, realized in order to achieve the object of the present invention, in its most basic form, comprises a glass sheet; a reflective metallic layer overlying the glass sheet; at least one protective layer overlying the metallic layer; at least one adhesion layer in the portion of the protective layer where it contacts the metallic layer; preferably a passivation layer overlying the adhesion layer; at least one first (primer) paint layer overlying the passivation layer or adhesion layer; at least a second protective paint layer overlying the first (primer) paint layer. The solar mirror that is the subject of the invention consists of three basic layers. The said layers are the glass sheet, the reflective layer and the protective layer.

The glass sheet constitutes the basic structure of the solar mirror, which is the subject of the invention. The glass sheet is made of glass material. The glass sheet has high transmittance and is completely transparent and colorless.

The reflective layer is positioned above the glass sheet. The reflective layer is used to reflect sunlight. The reflective layer is a metal having high reflectivity, preferably a silver layer is used, and the reflective layer is made of silver. While producing the reflective layer, silvering deposition method is used.

The protective layer is above the reflective layer. The protective layer is used to prevent corrosion of the reflective layer. The protective layer consists of the adhesion layer, the passivation layer, the first primer layer and the second protective paint layer.

The adhesion layer forms the lower part (base) of the protective layer. The adhesion layer is used to combine the protective primer layer with the reflective metallic layer.

The first primer layer is above the adhesion layer. The said paint layer is used to prevent corrosion of the reflective layer by covering the adhesion layer, hence the reflective metallic layer. The paint layer is used to increase the resistance of the reflective layer against abrasion, external exposures and corrosion.

Detailed Description of the Invention A solar mirror realized to achieve the object of the present invention is shown in the attached figures, wherein;

Figure 1. is a schematic view of the layers in the embodiment of a solar mirror that is the subject of the invention, which does not contain a protective metallic copper layer.

Figure 2. is a schematic view of the layers in the embodiment of a solar mirror that is the subject of the invention, which contains a protective metallic copper layer.

The components given in the figures are enumerated individually, and the meanings of these numbers are given below.

1. Solar mirror

2. Glass sheet

3. Reflective layer

4. Protective layer

4.1. Adhesion layer

4.2. Passivation layer / Protective metallic copper layer

4.3. First paint layer

4.4. Second paint layer

The invention solar mirror (1) with increased durability, used in outdoor applications, concentrated solar power plants, and used to reflect incoming sunlight and focus it on a fixed receiver, comprising a glass sheet (2) forming the base layer, a reflective layer (3), which is made of metallic material and is found on the glass layer (2) to reflect sunlight, a protective layer (4) on the reflective layer (3) used to prevent corrosion and damage to the reflective layer (3), characterized in that; the protective layer (4) comprises at least one adhesion layer (4.1), at least one first primer layer (4.3) and at least one second protective paint layer (4.4), a silane-based adhesion layer (4.1), which is located between the reflective layer (3) and the first paint layer (4.3), completely covers the reflective layer (3) and enables the reflective layer (3) and the first paint layer (4.3) to adhere to each other, a polyester-based or alkyd-melamine-based first primer paint layer (4.3), which is on the adhesion layer (4.1) and ensures increasing the durability by protecting the metallic layer (3) by covering the adhesion layer (4.1) and thus the metallic layer (3), a second polyurethane-based protective paint layer (4.4), which is on the first primer paint layer (4.3), completely covers the first primer paint layer (4.3), and is used to protect the first primer paint layer (4.3) and hence the reflective layer (3) against external exposures.

The solar mirror (1), which is the subject of the invention, is used especially in concentrated solar power plants to reflect the light coming from the sun and focus it on a fixed receiver. The solar mirror (1) that is the subject of the invention is preferably a solar tracking system (heliostat)mirror.

The solar mirror (1) which is the subject of the invention consists of glass sheet (2), a reflective layer (3) and a protective layer (4).

The glass sheet (2) constitutes the base layer of the solar mirror which is the subject of the invention. The glass sheet (2) is manufactured from silica and silica- containing materials. In addition, the glass sheet (2) may preferably contain a low amount of iron. The glass sheet (2) is colorless and transparent, and its thickness can vary according to the preferred embodiment of the invention. There is a reflective metallic layer (3) on the glass sheet (2). In an embodiment of the invention, the thickness of the glass sheet (2) is between 0.5 millimeters and 5 millimeters. In the preferred embodiment of the invention, the glass sheet (2) is first cleaned and polished while obtaining the solar mirror (1). Before the reflective metallic layer (3) is placed on the glass sheet (2), the glass sheet (2) is cleaned and polished. The glass sheet (2) is first cleaned using a cerium oxide chemical with the help of a brush. In the said embodiment, wetting agent can preferably be added to the cerium oxide chemical to increase the efficiency of cleaning. During the cleaning phase of the glass sheet (2), the brushes clean the surface of the glass sheet (2) with horizontal, vertical, diagonal and circular movements. It is ensured that the cleaning process is carried out homogeneously with the brush movements in question. After the cleaning process, the cerium oxide chemicals remaining on the glass sheet (2) are removed from the glass sheet (2) with the help of cleaning water. Deionized water is preferably used as cleaning water in order to prevent contamination, especially deformation and white clouding defects caused by cerium oxide on the glass sheet (2). The resistance of said cleaning water is at least 5 Ma-cm.

In the preferred embodiment of the invention, the sensitization process is performed on the glass sheet (2). The said sensitization process is carried out in order to hold the reflective metallic layer (3) on the glass sheet (2) more firmly. By applying a stannous chloride solution on the cleaned glass sheet (2), tin zones are formed in the glass sheet (2), which serve as nucleation centers for the silver layer deposition process. This serves to speed up the rate of silver deposition and improve the adhesion of silver to glass. In embodiments where the metallic reflective layer (3) is not protected by copper, the surface of the sensitized glass sheet (2) is activated using palladium solution. This application increases the valence of the tin that serve as nucleation centers for the silver layer deposition process. This serves to speed up the silver deposition rate and to improve the adhesion of the silver to the surface of the glass sheet (2). Activation of the surface is carried out by applying a palladium chloride solution on the glass sheet (2). After said sensitization and surface activation processes, the glass sheet (2) is cleaned with cleaning water. While the reflective layer (3) is being formed, the glass sheet (2) is not dried so that it spreads more homogeneously on the surface. The reflective layer (3) is located on the upper surface of the glass sheet (2). Said reflective layer (3) is made of metallic material. The reflective layer (3) is made of metals with high reflectivity, preferably silver. The reflective layer (3) is the layer that allows the sunlight to be reflected.

In the preferred embodiment of the invention, the reflective layer (3) is made of silver material and by silvering deposition method. The silvering deposition process is carried out by the chemical precipitation method. After the sensitization solution is thoroughly rinsed from the surface of the glass sheet (2) with deionized water and the surface is still wet, silvering chemicals are sprayed onto the sensitized glass sheet (2). The silver deposition method is carried out by applying silver, abrasive and reducing agents to the surface. The most commonly used chemical precipitation system consists of three separate solutions: a silver solution such as silver nitrate, a caustic such as sodium hydroxide, and a reducing agent such as dextrose. These three chemicals come together by simultaneously spraying the solutions on the surface of the glass sheet (2). The chemical reaction that occurs causes a silver layer to precipitate. The chemicals are transferred to the surface of the glass sheet (2) with the help of spray. The speed and frequency of the spray process and the targeted silver layer thickness are adjusted. After the silvering is complete, the solutions are removed from the surface of the glass sheet (2) to terminate the precipitation reaction, and rinsed thoroughly.

In one embodiment of the invention, the passivation of the reflective layer (3) is optimized. In order to increase the resistance of the reflective layer (3) against corrosion, the reflective layer (3) is passivated. The passivation process is carried out after the silver deposition process. The passivation process is carried out by increasing the number of tin atoms on the reflective layer (3). Said passivation is achieved by forming a precipitate layer on the reflective layer (3) with a cation solution containing tin, for example normally SnC12, and an anion solution consisting of hydroxyl ions, for example NaOH. Corrosion is prevented on the surface of the reflective silver layer (3) obtained by this water-insoluble precipitate. In an embodiment of the invention, there is a protective metallic copper layer (4.2) on the adhesion layer (4.1), hence the reflective layer (3). The protective metallic copper layer (4.2) can also be called the passivation layer (4.2). Said passivation layer (4.2), in other words, protective metallic copper layer (4.2), is used to passivate the reflective layer (3) and increase the resistance of the reflective layer (3) against corrosion. The passivation layer (4.2) is made of copper. Said copper layer (4.2) is manufactured using the chemical precipitation method. In particular, soluble copper solution such as copper sulfate is used. The solutions meet each other on the surface of the silver material and the precipitation process begins. Upon completion of the copper deposition process, copper solutions on the surface are removed. Copper removal is preferably carried out by washing. The passivation layer (4.2) increases the resistance of the reflective layer (3) against corrosion.

In the preferred embodiment of the invention, the production of the reflective layer (3) is carried out using the wet deposition technique.

In a different embodiment of the invention, the production of the reflective layer

(3) is formed by using chemical vapor deposition, physical vapor deposition or sputter deposition methods.

The protective layer (4) is on the reflective layer (3). Said protective layer (4) is used to protect the reflective layer (3) against corrosion and external influences. The thickness and color of the protective layer (4) can vary. The protective layer

(4) consists of the adhesion layer (4.1), the passivation layer (4.2), the first primer paint layer (4.3) and the second protective paint layer (4.4).

The adhesion layer (4.1) is on the surface of the protective layer (4) where it contacts the reflective layer (3). The adhesion layer (4.1) is located between the paint layer (4.2) and the reflective layer (3). The adhesion layer (4.1) is used to ensure that the paint layer (4.2) adheres more firmly to the surface of the reflective layer (3).

In the preferred embodiment of the invention, the adhesion layer (4.1) is formed with the help of silane coupling agents. In the said embodiment, a chemical with an organosilane structure is used. The -OH ends in the structure of the organosilane chemical are attached to the surface of the reflective layer (3). The organic (-R) end of the organosilane chemical is attached to the first paint layer (4.3). This situation establishes a bond between the reflective layer (3) and the first paint layer (4.3), and ensures that the layers adhere to each other better. In this way, the resistance of the mirror against abrasion and corrosion is increased with the increased adhesion formed between the metallic layer (3) and the first paint layer (4.1).

The silver coating may be coated with one or more layers of protective paint (4.4), and according to a preferred aspect of the present invention such paint is lead-free or substantially lead-free. In cases where more than one such paint protection layer (4.4) is used, the paint layers other than the top protective paint layer (4.4) may contain lead. However, for environmental health reasons, lead sulfate and lead carbonate are preferably absent in the lower paint layers (4.4), so if lead is present in these substrates (4.4), it is preferably in the form of lead oxide.

The protective paint layers (4) used provide physical and chemical resistance to the solar mirror (1), which is the subject of the invention, against outdoor conditions. Paints used in the protective paint layer (4.4) can be alkyd, acrylic, polyester, polyurethane and/or epoxy. In an embodiment of the invention, the paints used in the first paint layer (4.3) can be alkyd-melamine, alkyd, acrylic, polyester, polyurethane and/or epoxy.

The first primer layer (4.3) is above the adhesion layer (4.1). The first paint layer (4.3) is used to protect the reflective layer (3) against external influences. The color of the first paint layer (4.3) changes. In the preferred embodiment of the invention, the first paint layer (4.3) is formed by using polyester-based paint.

In the preferred embodiment of the invention, the first paint layer (4.3) is carried out by the curtain coating method. Curtain coater equipment is open to the atmospheric environment. There is paint in the reservoir of the curtain coating equipment. The paint is poured onto the glass sheet (2) moving on the conveyor with the help of the roller moving in the chamber. With the continuity of the curtain, a homogeneous and one-piece coating is formed. The curtain forming performance of the paint depends on the paint's structure, properties, application viscosity and ambient conditions. The thickness of the coating is controlled by the amount of paint and the feed rate of the mirror.

The second paint layer (4.4) is above the first paint layer (4.3). Said second paint layer (4.4) is used to increase the durability by protecting the first paint layer (4.3) and hence the reflective layer (3). In the preferred embodiment of the invention, the second paint layer (4.4) is formed by using a polyurethane-based paint.

In the preferred embodiment of the invention, the first primer paint layer (4.3) and the second protective paint layer (4.4) are applied. The drying process is applied to the first paint layer (4.3). In the drying process, the first layer of paint is pre-drying at low temperature and the amount of solvent contained in the paint is reduced with the help of evaporation. The pre-cured mirror with the first coat of paint (4.3) comes to the second curtain coating station, where the second coat of protective paint (4.4) is applied. After the second paint layer (4.4) has been applied, it is cured, preferably with the aid of a heating oven.

In the preferred embodiment of the invention, the curing process is applied to the first paint layer (4.3) and the second paint layer (4.4). The curing type and conditions vary according to the physical and chemical properties of the paint layer (4.2) and the second paint layer (4.4). In the said embodiment, the paint layer (4.2) and the second paint layer (4.4) are cured with the help of heat.

In an embodiment of the invention, the first paint layer (4.3) is carried out using primer paint. In the case where the invention includes a copper layer (4.2), an alkydmelamine based paint is used for the first paint layer (4.3). The alkyd-melamine based paint system contains a low amount of lead oxide pigment.

In this solar mirror (1), a protective metallic copper layer (4.2) is used to protect the metallic reflective layer (3) of the mirror. It is to increase the exterior resistance of the mirror by using the second paint layer (4.4), which is a polyurethane -based topcoat paint application, on the first paint layer (4.3), which is the primer paint, in both cases when the protective metallic copper layer (4.2) is used or not.

In another embodiment of the invention, the first paint layer (4.3) is formed with polyester-based paint. The first paint layer (4.3) formed by using polyester-based paint is used to increase the resistance of the reflective layer (3) against corrosion and other external effects.

In an embodiment of the invention, the glass sheet (2), the reflective layer (3) and the protective layer (4) form the solar mirror (1), which is the subject of the invention, and their thickness is as follows. The thickness of the glass sheet (2) is between 0.5mm and 10mm. The thickness of the reflective layer (3) is between 50nm and 300nm. In the said embodiment, the protective layer (4) includes the first paint layer (4.3) and the second paint layer (4.4). The thickness of the first paint layer (4.3) is between 10pm and 100pm. The thickness of the second paint layer (4.4) is between 10pm and 100pm. The thickness of the protective layer (4) is between 20pm and 300pm.

In another embodiment of the invention, the glass sheet (2), the reflective layer (3) and the protective layer (4) form the solar mirror (1), which is the subject of the invention, and their thickness is as follows. The thickness of the glass sheet (2) is between 0.5mm and 10mm. The thickness of the reflective layer (3) is between 50nm and 300nm. In the embodiment, the protective layer (4) includes the passivation layer (4.2), the first paint layer (4.3) and the second paint layer (4.4). The thickness of the passivation copper layer (4.2) ranges from 50nm to 300nm. The thickness of the first paint layer (4.3) is between 10pm and 100pm. The thickness of the second paint layer (4.4) is between 10pm and 100pm. The thickness of the protective layer (4) is between 20pm and 300pm.

Claims

CLAIMS The invention is a solar mirror (1) with increased durability used to reflect sun light to focus the light on a fixed receiver, especially in concentrated solar power plants and solar farms generating energy from the sun, comprising: a glass sheet (2) forming the base layer, a reflective layer (3) made of metallic material and found on the glass sheet (2) in order to reflect sunlight, a protective layer (4) found on the reflective layer (3), and used to prevent abrasion and damage to the reflective layer (3), characterized in that; the protective layer (4) comprises at least one adhesion layer (4.1), at least one first paint layer (4.3) and at least one second paint layer (4.4), the adhesion layer (4.1) having silane structure and being located between the reflective layer (3) and the first paint layer (4.3), and completely covering the reflective layer (3) and allowing the reflective layer (3) and the first paint layer (4.3) to adhere to each other, the first paint layer (4.3) being polyester-based or alkyd-melamine-based, being found on the adhesion layer (4.1) and ensuring increasing the durability by protecting the metallic layer (3) by covering the adhesion layer (4.1) and thus the metallic layer (3), the second paint layer (4.4) being polyurethane-based, and being found on the first paint layer (4.3), completely covering the first paint layer (4.3), and being used to protect the first paint layer (4.3) and hence the reflective layer (3) against external exposures. The solar mirror (1) according to Claim 1, characterized in that; cleaning and polishing operations are performed on the glass sheet (2) by using cerium oxide chemical, before the reflective layer (3) is placed on the glass sheet (2). The solar mirror (1) according to Claim 2, characterized in that; cerium oxide residues on the glass sheet (2) are cleaned with deionized water with a resistance of at least 5 Mfl-cm to prevent the formation of cerium oxide-induced deformation and white clouding. The solar mirror (1) according to Claim 1, characterized in that; by applying tin chloride solution on the glass sheet (2), the glass sheet (2) is sensitized and the adhesion of the reflective layer (3) is increased on the glass sheet (2). The solar mirror (1) according to Claim 1, characterized in that; the surface of the glass sheet (2) is activated by applying a palladium chloride solution on the glass sheet (2), before the reflective layer (3) is placed on the glass sheet (2). The solar mirror (1) according to Claim 1, characterized in that; it comprises the reflective layer (3) made of silver material, a silver material obtained by using chemical precipitation method. The solar mirror (1) according to Claim 1, characterized in that; it comprises the reflective layer (3) with increased resistance to corrosion, which is passivated by increasing the number of tin atoms on its surface by forming a precipitate layer with a cation solution comprising tin and an anion solution consisting of hydroxyl ions. The solar mirror (1) according to Claim 1, characterized in that; it comprises at least one passivation layer (4.2) which is used to increase the resistance of the reflective layer (3) against corrosion by passivation of the reflective layer (3) by being made of copper material that covers the reflective layer (3) on the adhesion layer (4.1). The solar mirror (1) according to Claim 1, characterized in that; it comprises the silver reflective layer (3) obtained by using one of the chemical vapor deposition, physical vapor deposition or sputter deposition methods. The solar mirror (1) according to Claim 1, characterized in that; it comprises: the glass sheet (2) having a thickness of 0.5mm to 10mm; the reflective layer (3) having a thickness of 50nm to 300nm; the first paint layer (4.3) having a thickness of 10pm to 100pm; the second paint layer (4.4) having a thickness of 10pm to 100pm. The solar mirror (1) according to Claim 8, characterized in that; it comprises the copper passivation layer (4.2) with a thickness of 50nm to 300nm. The solar mirror (1) according to Claim 8, characterized in that; it comprises the first paint layer (4.3) manufactured using alkyd-melamine, alkyd, acrylic, polyester, polyurethane, epoxy or polyurethane and epoxy-based protective paint. The solar mirror (1) according to Claim 1, characterized in that; the protective metallic copper layer (4.2) is used to protect the metallic reflective layer (3) of the mirror, and in both cases where the protective metallic copper layer (4.2) is used or not, the exterior resistance of the mirror is increased by using the second paint layer (4.4), which is a polyurethane-based topcoat paint application, on the first paint layer (4.3), which is the primer paint. The solar mirror (1) according to Claim 1, characterized in that; the paints used in the protective paint layer (4.4) are alkyd, acrylic, polyester, polyurethane, epoxy or polyurethane and epoxy. The solar mirror (1) according to Claim 8, characterized in that; the passivation layer (4.2) is made of copper using chemical precipitation method, and soluble copper solution such as copper sulfate is used during precipitation.

17