To construct a solar panel, one requires several solar cells made of doped silicon as has been discussed before. These cells are connected in series to add up the resultant current. This gives strips of clustered cells called a module. A single module could be constructed into a solar panel or combined with others in cases where a large panel is required.
A solar panel consists of several layers that sandwich the photovoltaic cells. These layers are used to protect the fragile cells.
An illustration of the layers is given below −
The layers consist of the following parts −
Cover Glass − This is the top cover and is transparent to allows light to enter. It prevents the cells from mechanical damage. It is made of hard glass to prevent against scratch.
Non-reflective layer − Silicon can reflect most of the sunlight. Therefore, this layer is used to counter this and ensure maximum absorption of photons. In other words, it helps to maximize absorption.
Contact grid − At this layer, all the contacts joining top to bottom of cells are connected together. The contact extends to the external parts of the panel like charge controller, combiner box and battery storage or grid system.
P and N Silicon plates − This layer is actually a combination of two layers − the Ndoped silicon layer and P-doped silicon layer. This layer gives the solar panel its color.
Back plate − This is a hard layer for supporting the crystalline photovoltaic panels. At times, flexible synthetic fibers may be used for thin-film type panels.
Aluminum frame is used to frame the panel and to make it weatherproof. The benefits are −
The frame provides a means of mounting the panel on surfaces such as rooftops.
The frame is tight enough to protect the panel against extreme weather conditions such as storms.
The solar panel should also be under constant care to prevent dust particles from resting on it. During the installation process, the panels should be fixed at an angle to receive maximum light. A proportional battery should be set in place in cases of no direct usage, to avoid waste.