Most bulk silicon PV modules consist of a transparent face, an encapsulant, a backside and a frame around the outer edge. In most components, the top surface is glass, the encapsulant is EVA (vinyl acetate), and the back is PET. This is only for glass solar panels. The surface of the flexible component may be ETFE or PET, and the back of the patch component is PCB.
Photovoltaic module surface material
The front surface of the photovoltaic module must have a high light transmittance in the wavelength range that the solar cells in the photovoltaic module can use. For silicon solar cells, the top surface must have high light transmission in the wavelength range from 350nm to 1200nm. Also, the reflection of the front surface should be low. While in theory this reflection could be reduced by applying anti-reflective coatings on the top surface, in practice these coatings are not strong enough to withstand the conditions of use of most photovoltaic systems. Another technique for reducing reflections is to “roughen” or texture the surface. In this case, however, dust and dirt are more likely to adhere to the top surface and less likely to be dislodged by wind or rain. As a result, these components are not “self-cleaning” and the benefits of reduced reflections are quickly outweighed by losses due to increased top surface fouling.
In addition to reflective and transmissive properties, the surface material should be impervious to water, should have good impact resistance, should be stable under prolonged UV exposure, and should have low thermal resistivity. Water or water vapor entering the photovoltaic module will corrode the metal contacts and interconnection devices, thus greatly reducing the service life of the photovoltaic module. In most components, the front surface is used to provide mechanical strength and stiffness, so the surface or back surface must have mechanical stiffness to support the solar cells and wiring.Please refer to:72 volt lithium ion battery golf cart
There are several options for surface materials, including acrylic, polymer, and glass. Tempered, low-iron glass is most commonly used because it is low cost, strong, stable, highly transparent, impermeable to water and gases, and has good self-cleaning properties.
Photovoltaic module encapsulants
Encapsulants are used to provide adhesion between solar cells, top and rear surfaces of photovoltaic modules. The encapsulant should be stable at high temperature and high UV exposure. It should also be optically transparent and should have low thermal resistance. EVA (Ethyl Vinyl Acetate) is the most commonly used encapsulation material. EVA is in the form of a thin sheet, which is inserted between the solar cell sheet and the top surface and the back. This interlayer is then heated to over a hundred degrees to polymerize the EVA and bond the components together.
Photovoltaic module rear surface
The main characteristics of the rear surface of a photovoltaic module are that it must have low thermal resistance and must prevent the ingress of water or water vapor. In most modules, a thin polymer sheet is used on the back surface. Some photovoltaic modules, known as bifacial modules, are designed to receive light from either the front or the back of the solar cells. In a bifacial assembly, both the front and back must be optically transparentPlease refer to:https://www.aminobattery.com/
Photovoltaic module frame
The final structural component of a solar panel is the bezel or frame of the solar panel. Traditional photovoltaic module frames are usually made of aluminum. Framing should be free of protrusions that could trap water, dust, or other substances.