Imagine the whole world is being run by just one energy source and interestingly, that source is nearly 150 million kilometers from here! Well, it’s not just a mere imagination, it’s the near future! This is what the solar cell technology aims to achieve. And it’s on its way to do so. But what is the truth about solar power? Can it really change this planet? In this article, we’ll take a look at the current state of this technology. It seems that a solar movement is at its vibe. So, let’s check it out.
What is a Solar Cell Technology?
A solar cell, otherwise known as a photovoltaic cell, is a device that converts light energy into electrical energy. Actually, photovoltaic cells are the most basic structural and functional unit of the solar power generation process. The conversion of light energy, which is received as packets of energy or quanta called photons, to electrical energy is called the photovoltaic effect. The field that the solar cells fall into is known as photovoltaics.
Photovoltaic cells and solar cells, though almost synonymous, are however different slightly. The photovoltaic cell includes both solar and non-solar sources of light e.g. that of an incandescent bulb. Whereas solar cells deal with the sunlight only.
How do solar cell technology work?
Whether you have a few cells or a billion, the principle is the same.
A solar cell is composed of four major components: a top layer of transparent barrier, a semiconductor wafer (mostly silicon), a basement layer and conductors that link up all these components. The barrier layer is composed of a layer of metal (used as a cathode) and a thin transparent film. It is formed by the cathode-sputtering the semitransparent layer. The backing layer is typically made of metals like iron etc.
Basically, the semiconductor wafer, placed in a sandwiched position, consists of two layers of which one is electron rich while the other is rich in holes. A hole is nothing but the absence of an electron. The electrons and holes remain confined to their respective portions due to the potential barrier that exists in semiconductors. When sunlight, and hence photons, fall on the semiconductor passing through the transparent layer the electrons gain sufficient energy to cross the potential barrier and fill up the hole. In this way gradually a flow of electrons and hence current flow is generated. The electrons then flow through the external circuit and get back to the basement layer. Thus electricity is produced. This electrical energy can be used directly or stored in batteries which are a more practical and effective way. In many places of the world, the output is directly fed to the main power grid.
Well, why is silicon mostly used? Silicon is the second most abundant element in the Earth and it is also chosen in most of the cases due to its semiconducting potential.
One cell, usually, is neither efficient nor able to meet up our usual requirements. The more cells toy have, the more sunlight you have and hence more electricity you generate. So a group of such solar cells, known as solar panels, are set to use practically. In large scale, solar power generation arrays of solar panels are used which are referred as solar farms.
Why use Solar Cells in Power Generation?
The Earth receives 3.85 gotta or septillion (x10^24) joules energy from the sun through its atmosphere and surface- land and sea per year. One hour of this energy exposure is more energy than the entire world consumes in one year. Or in another point of view, one year of this exposure from the sun contains twice as much as energy than we’ll ever we gained from all the earth’s none renewable resources like coal oil, natural gas, and mined uranium combined. Trapping just a fraction of this mammoth energy exposure means a lot to anyone and everyone. Practically speaking, we can use 0.4 to 13 percent of this energy.
One of the greatest threats the world is facing at present is global warming. It is caused due to the greenhouse effect which is the result of ever-increasing greenhouse gases in the atmosphere. And the prime reason of greenhouse gas accumulation in the natural air is excessive use of none renewable fossil fuel for energy generation. Undoubtedly the increase of use of renewable resources is the solution to this problem and the solar cell energy generation procedure is the best and most effective one in this regard.
Our world has a huge population which does not get facilities of electricity. Again several countries have a shortage of its production in comparison to the demand. Solar cells require no complex method in production nor in storage or supply. So power generation using solar cells is a great solution to many of the existing shortcomings the modern world is facing and dealing with right now.
Types of Solar Cell
Amorphous Silicon solar cell (a-Si): It is also known as thin film solar cell. The semiconductor used in such cells is the on crystalline silicon. It is very environment-friendly since it does not contain any toxic material though its efficiency is less.
Biohybrid solar cell
It is a new solar cell technology. Here the natural process of photosynthesis is recreated and incorporated in solar cells in order to obtain much higher efficiency. Photosystem I, an organic matter, is used in it in a combination with other inorganic materials.
Buried contact solar cell
This type of solar cell was invented by University of New South Wales (UNSW) in 1984. These solar cells contain a textured exposed frontal portion with silicon dioxide passivation. It’s the efficiency of approximately 25%.
Some other types of solar cells
Hybrid solar cells, Concentrated Photovoltaic cell (CVP and HCVP), Copper indium gallium selenide solar cells (CI(G)S), Crystalline silicon solar cell (c-Si), Dye sensitized solar cell (DSSC), Gallium arsenide germanium solar cell (GaAs), Luminescent solar concentrator cell (LSC), Micromorph (tandem-cell using a-Si/μc-Si), Monocrystalline solar cell (mono-Si), Multi-junction solar cell (MJ), Perovskite solar cell, Nanocrystal solar cell, Organic solar cell (OPV), Photoelectrochemical cell (PEC), Plasmonic solar cell, Plastic solar cell, Cadmium telluride solar cell (CdTe), Polycrystalline solar cell (multi-Si), Polymer solar cell, Quantum dot solar cell, Solid-state solar cell, Thin-film solar cell (TFSC), Crystalline silicon solar cell.
Note that the organic solar cells are more advantageous than the inorganic solar cells. It is because the inorganic solar cells are not flexible, more expensive and require thicker materials. While, on the other hand, organic solar cells are cheaper and easier to install.
Applications of Solar Cell Technology
Now it is time to check out how this awesome technology is contributing to making our life a lot smoother and comfortable. Some practical application of solar cell technology are as follows-
Toys: Various interesting toys are now available which do not require the traditional batteries.
Watches: Watch that utilizes the sunlight energy with the help of solar cells in it are constructed in such a way that the dial is on the solar panel. In it, the battery is also used to store charge in dark situations.
Calculator: Almost all calculators nowadays use solar cells on them for charging its batteries.
Vehicles: Electrical energy is being used to run a number of vehicles in modern days. Many of them contain solar panels. Though general mass is not well acquainted with these gadgets, in recent future life will be depending on them.
Portable power supply
Nowadays power supplies are being manufactured that enables provide power using solar energy. One can get the power supply in any place of the world or even outside the Earth using this technology. This helps use electrical and electronic devices where electricity cannot be supplied via traditional means.
Solar batteries are nothing but batteries that store electrical energy generated by solar panels. But it’s a lot more than what it sounds to be when it becomes a part of a solar energy system. The batteries work by converting AC energy that is produced by the solar panels into DC energy.
Solar energy system
Solar energy system, typically, includes solar panels, an inverter or adapter, solar batteries, a technological setup that checks your energy production and devices and equipment required for panels mounting and installation. During daytime, the batteries are charged and provide electricity for consumption simultaneously. During night or when the sky is dark, the batteries provide electricity from its storage. If there is a shortage of required electricity the system draws energy from the main power grid. While on the other if the production is greater than the demand, it is fed to the main power grid.
Solar power is unanimously the cleanest and most environmentally friendly among the on renewable power generation methods. It gives us the facilities to store energy in various forms. It reduces the use of fossil fuel. Still many are there to decelerate the pace in which it is propagating. The reason is the hamper of their business conditions. It is high time we became aware of the fact that the future is of solar cell technology.