Colored solar modules and their applications

Abstract

Colored solar modules characterized by the application of fluorescent pigment colors to the front glass of solar modules fully and / or partially covered with solar cells, wherein the optical transmission of the coatings produced in this way is greater than 80% and the power efficiency of the solar modules is at least 85% compared to uncoated modules.

Description

[0001] The invention relates to spectrally light-changing fluorescent coatings on solar modules.

[0002] The use of colored solar modules has attracted increasing interest. Colored solar modules are gaining particular importance in building-integrated photovoltaics (BIPV). The application of colored layers is intended to have only a negligible impact on the efficiency of the solar modules. Morpho-Color coatings for BIPV are based on a photonic structure that, by combining an interference layer with a geometrically structured substrate, generates a narrowband reflection maximum, thereby creating colored module surfaces. The optical transmission of the resulting coatings exceeds 90% (https: / / megasol.ch, https: / / kurzelinks.de / nqir). Colored layers on solar facades for BIPV are also achieved using printing techniques, producing differently colored solar modules that exhibit an efficiency of over 80% compared to uncoated modules (www.konvortec.de).Tinted solar front glass for colored solar modules is also suitable for BIPV (www.sunovation.de). Red solar modules are used as solar roof tiles in listed buildings (www.axsun.de). Printing interference layers onto solar modules creates colored layers with anti-glare properties and special design characteristics, and also serves to protect birds (www.spricolorpv.com). Colored films are also used, which are applied to the solar modules. These films are produced using nanoimprinting processes (Win Future, September 3, 2025). When using fluorescent dyes, e.g., perylene-based, colored transparent coatings with an optical transmission of over 85% are obtained. Due to their high optical transparency, the color of the solar cells used in the solar modules is not obscured, and thus, colored solar modules are not produced.The fluorescent coatings mentioned in PCT / DE 2022 / 000110 and DE 2024 000 848 A1 are not suitable for colored solar modules because they allow too little solar radiation to pass through and their efficiency is thereby greatly reduced.

[0003] The listed technical solutions have several disadvantages. Building-integrated photovoltaics with colored decorative films exhibit insufficient optical transmission (less than 80%), resulting in low efficiency for the solar modules. Higher-efficiency technologies are more complex and expensive to implement. Insufficient adhesion of colored films also hinders effective application. Colored solar front glass is likewise too costly. The use of color pigments and nanomaterials in the layers leads to excessive absorption, resulting in low power efficiency of the solar modules. Finally, the listed dye layers are subject to UV degradation, negatively impacting the stability of the colored solar modules.

[0004] The invention aims to provide colored coatings that, compared to uncoated modules, exhibit an optical transmission greater than 80%, good adhesion to the glass substrate, high opacity, efficient conversion of UV light into longer-wavelength radiation, and high weather resistance. Furthermore, the colored coatings should be technologically easy to apply and inexpensive. When applied to solar modules, the coatings should result in only negligible power losses. The invention achieves this objective by using fluorescent pigment colors, such as matte neon automotive paints in yellow / green, red, or Belton neon paints in yellow, red, or orange, for the colored coatings. Binders based on nitrocellulose resins are used, in which the pigments are embedded.In the technological application of colored coatings, the coatings are applied using spraying, aeration, or printing techniques to the surfaces of the solar front glass on the solar modules that face the solar radiation. To reduce UV degradation of the colored coatings, the coating can also be applied to the surfaces of the front glass that face away from the incident solar radiation, but before the solar modules are fully assembled. After the colored coatings have dried, two-coat automotive or Belton clear coats are applied for improved weather resistance and better resistance to mechanical stresses of the resulting coating system. The primary application of colored coatings is on solar modules fully populated with solar cells.Another application of the color coatings concerns ground-mounted solar modules where the front glass is only partially covered with solar cells and which have adjustable optical transmission, particularly in agricultural photovoltaics (Agri-PV). The coating of the solar modules' front glass ensures a homogeneous light distribution beneath the modules in the case of ground-mounted modules, promoting plant growth, especially when red coatings are used. The color coatings according to the invention have high optical transmission, so that the coated solar modules exhibit only a slight loss in power efficiency compared to uncoated modules. At a UV index greater than 5, the optical transmission of the color layers reaches values ​​exceeding 85%. The colored solar modules according to the invention offer a number of further advantages.Their applied color layers efficiently convert UV radiation into a wavelength range more favorable for the solar cells used, thus contributing to an increase in the modules' solar power output. By converting the UV radiation into longer-wavelength light, the solar cells are protected from UV degradation. The colored coating is applied to the modules. The colored solar modules according to the invention find a variety of advantageous applications. In ground-mounted and agricultural PV systems, green / yellow colored solar modules significantly increase their acceptance. Green / yellow colored solar modules also blend harmoniously into vertical farming systems. A high market potential is expected for the colored solar modules according to the invention in ground-mounted PV, agricultural PV, and building-integrated PV. They find advantageous applications, for example, on roofs, house walls, stadiums, and other buildings. Red solar modules are advantageously used on roofs of listed buildings. Examples of implementation

[0005] 1. Colored fluorescent pigment coatings, such as neon automotive paints in yellow / green or red, are applied to a standard solar module equipped with monocrystalline solar cells using spraying, aeration, or printing techniques. After the coatings have dried, two-coat automotive clear coats or Belton clear coats are applied. Following this coating treatment, the solar modules have a power output of 340 Wp, compared to the 400 Wp output of uncoated modules. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 2022 / 000110

[0002] DE 2024 000 848 A1

[0002]

Claims

[1] Colored solar modules characterized in that fluorescent pigment colors are applied to the front glass of solar modules fully and / or partially covered with solar cells, wherein the optical transmission of the coatings produced in this way is greater than 80% and the power efficiency of the solar modules is at least 85% compared to uncoated modules. [2] Colored solar modules according to claim 1, wherein the fluorescent pigment colors consist of neon automotive paints, yellow / green or red or of Belton neon paints, yellow, red, orange, and nitro combination resins are used as binders and clear coats are applied to the color layers to improve their weather resistance. [3] Colored solar modules according to any of the preceding claims 1 to 2 for use in building PV, in ground-mounted PV and AGRI-PV and in particular on roofs, on house walls, on conservatories, on sports and event stadiums, on parking lots and on the edges of highways. [4] Colored solar modules according to any of the preceding claims 1 to 3 for protecting solar modules from UV degradation and weathering and for reducing their glare effect.