why solar panels have a silicon layer?
Answers
solar panel made up of silicon semiconductors is called a silicon solar panel. A number of PV cells aggregated in a confined panel act as a collector of solar energy. Silicon semiconductors are popular because they exhibit properties such as low weight volume ratio, extended life cycle, robustness and strength.
Answer:
Silicon solar panels: These can become a source of free electricity
Silicon solar panels: These can become a source of free electricity
Synopsis
Silicon solar panels come in varying sizes to suit various applications. Silicon solar panels typically comprise 32, 36, 48, 60, 72 and 96 PV cells
By Team ProductLineLast Updated: May 07, 2019, 05:36 PM IST
Importance of solar energy
Use of solar energy is a trend that is quickly gaining popularity in India as it is abundantly available in most parts of the country and more importantly it is a renewable source of energy, never to be extinguished. Although solar energy is easily available, harnessing that energy into useful purposes is a tricky affair. However, past research has shown that it can be harnessed into electric energy and current research is aimed at converting all the energy received into useful electric energy.
What are photovoltaic cells?
Conversion of solar energy into electric energy is accomplished by the principle of photovoltaic (PV) effect. PV effect is the process of converting the sun’s energy into electric energy through PV cells made up of semiconductors such as silicon. When sunlight falls on a PV cell, its constituents known as photons absorb the light energy received and transfer that energy to the electrons in the semiconductor material which then flows as electric current. This electric current becomes the source of electric power. One of the most popular semiconductor materials used in PV cells is silicon which has properties conducive to produce electric power from solar energy.
What are silicon solar panels?
A solar panel made up of silicon semiconductors is called a silicon solar panel. A number of PV cells aggregated in a confined panel act as a collector of solar energy. Silicon semiconductors are popular because they exhibit properties such as low weight volume ratio, extended life cycle, robustness and strength. Silicon semiconductors are easy to produce at low cost.
Silicon solar panels come in varying sizes to suit various applications. Silicon solar panels typically comprise 32, 36, 48, 60, 72 and 96 PV cells. Several of these panels can be connected in series or parallel to obtain higher electric power suitable for high power demanding applications.
Types of silicon solar panels
Basically, there are three types of silicon solar panels primarily classified on the basis of the type of PV cells in them. They can be categorized as monocrystalline, polycrystalline and amorphous or thin film solar panels. Each of these has different properties that can affect the output of the electric power generated.
Monocrystalline solar panels
Polycrystalline solar panels
Polycrystalline solar panels are made from PV cells cut from multiple silicon crystals. Melted silicon is poured into square moulds. After the silicon cools in the moulds it is cut into squares. The perfect square shape distinguishes the polycrystalline cell from the monocrystalline cell (which is octagonal in shape). These have the same properties as monocrystalline solar panels but offer lower efficiencies while converting solar energy into electric energy. These cells are cheaper to make than monocrystalline cells because there is less wastage of silicon.
Thin film or amorphous solar panels
Thin film or amorphous solar panels comprise a substrate on which thin layers of amorphous silicon is deposited. These are becoming popular because of its mass production capability and use where the surface area for deploying the panels is not a constraint. Amorphous solar panels have low efficiency and therefore are used in small applications such as pocket calculators. But with the new ‘stacking’ technique, layers can be combined to improve efficiency (6-8%). Because amorphous solar panels are flexible, they can be used in innovative ways on curved surfaces too.
Applications of silicon solar panels
Almost 90% of the applications of solar power use silicon solar panels for generating electric power. The many applications of silicon solar panels are as follows:
In power plants, silicon solar panels provide the necessary energy to boil water and produce steam that can rotate turbines to produce electricity. They can replace other forms of energy that are not renewable.
In households, silicon solar panels placed on rooftops can serve as a stand-alone system used to heat water for home consumption. These panels can also become a source of free electricity if they charge a rechargeable battery which can then be used to supply power to the homes.
In commercial establishments, in much the same way as in homes, silicon solar panels placed on rooftops or backyards can serve as primary or standby power.
In agricultural fields or homes, stand-alone solar power systems use silicon solar panels to power water pump to pump water to a field or to an overhead tank.
In swimming pools, silicon solar panels can keep the water in the pool hot during the winter.