While buying a solar panel one must keep in mind various factors like where it will be installed, purpose; commercial or residential use, and budget.
An Overview of Solar Panels
Yoey Thamas for | Green Yorkshire Solar
With the changing times and pacing technology, one has to take a step towards the sustainable development of the environment. To save environment, people now prefer to use renewable sources of energy to conventional sources. Government of the UK has taken a commendable step in conserving the environment by launching Feed-in-Tariff scheme. They have set an example in front of the whole world that how significantly pollution can be decreased by using solar panels for generating electricity.
All about Solar Panels
Solar panels are the collection of solar or photovoltaic cells which, convert solar energy i.e. sunlight into electrical energy or electricity. The process of extraction of electricity directly from sunlight is known as photovoltaic process. A photovoltaic cell or a self-generating barrier layer cell is also a PV detector which transforms radiant flux straight into electrical current. Moreover, electricity cannot be generated by heat through PV cells as sunlight is a must requirement for that.
The idea of producing electricity gained popularity in the recent times but it is actually a hundred year old initiative. Henri Becquerel made the discovery of photovoltaic effect and converted electricity directly from the sunlight. Thus, a century old thought is now being taken into practice by different countries. Furthermore, NASA is also using this technique to produce energy as the process is pollution free and noiseless.
Working of Solar Panels
Silicon is a semi-conductor, which means it is having a property of an insulator as well as of a metal. The apex layer is made up of phosphorous or arsenic which is used to dope silicon while bottom layer is doped with boron or gallium.
The chemistry behind it is that the phosphorous has five valance electrons. It gives its four electrons to silicon which forms the bond by freeing its fifth electron. Now when many phosphorous atoms are replaced in the silicon crystal there are numerous free electrons present which makes it n-type of silicon. The n-type of silicon implies majority of electrons. In case of boron silicon doping the crystal lattice of silicon misses an electron. Thus, it is p-type silicon having majority of holes and minority of electrons in it.
When sunlight light particles i.e. photon, directly falls onto the solar panel, electrons gets free. The work is not over yet. To produce electricity one needs to create an imbalance. This can be done when p-type and n-type silicon is tightly structured together. The extra electrons from n-type silicon jumps to take place in the holes present in the p-type silicon which creates an electric field on all over the cell. In addition to it, silicon is a semiconductor which indicates that it is an insulator thus can maintain the imbalance efficiently.
Materials used in making Solar Panels
Usually, silicon is doped by phosphorous or arsenic and boron or gallium. Recently, researches have come up with the new element Argonne III, which is much cheaper, efficient and reliable. Moreover, it also consumes less manufacturing time as compared to the silicon. This will make solar panels affordable to many who are unable to install it in their houses due to the high prices. Thus, it is a very significant discovery towards the sustainable development of environment for an extremely cost effective way.
Types of Solar Panels
There are different types of solar panels which are used by the people according to its utility. While buying a solar panel one must keep in mind various factors like where it will be installed, purpose; commercial or residential use, and budget. Below is the list of a few types of solar panels:-
1.) Polycrystalline Silicon Solar Panel
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As the name signifies, it is based on the polysilicon and multi-crystalline silicon. The raw silicon is first melted and then poured into a square mold, which is cooled and cut into perfectly square wafers. Moreover, it was introduced in the market in 1981.
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Polycrystalline panels have great life spans. It has been noticed that panels installed 25 years ago are still working impeccably.
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They have the efficiency ranging between 120 to 150 Watt meters square. There can be an exception of 12% to15%. The efficiency is considerably low as the crystal gain boundaries can trap electrons in it.
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Polycrystalline panels have lower heat coefficient i.e. it shows slightly lower high temperature ratings.
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Although, they take small areas for installation and are easily available but when compared to monocrystalline silicon solar panel, they are less efficient.
2.) Monocrystalline Silicon Solar Panel
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The monocrystalline Silicon Solar Panel is cut from the ingots which gives the panel a uniform layout. These astronomical sized crystals are hard to produce as they are rare and the process of recrystallising is extremely expensive.
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It has good power to size ratio with efficiency ranging in between 135-170 Watts per meters square. Moreover, some of the units are now having 18%efficiency conversion.
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The major drawback with it is that it is intolerant to shade and dust. Even if the single cell of the solar panel is under the shade, its efficiency will reduce to 20%.
3.) Amorphous or Thin-film Solar Panel
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Silicon is sprayed onto the substrate with the process of vapor deposition. Silicon water has a 1 micron thick layer which indicates that it uses less energy to produce and is less efficient as compared to mono or polycrystalline.
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It performs commendably in the hotter environments as compared to the other two panels but occupies greater space than that.
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As it uses less silicon and no aluminum frame is present, the embodied energy automatically becomes low.
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The Staebler-Wronski effect reduces the module efficiency and the main reason behind it is that the extended exposure to sunrays causes defect in the density of amorphous silicon
In the countries like the UK, industries dealing in solar panels are thriving at a high rate. There are discoveries and inventions being made, experts are researching on various matters to make it more efficient, reliable and affordable. Sooner or later their work will bring good results and would help the country create a better and more pollution free environment for their future generation.
The content & opinions in this article are the author’s and do not necessarily represent the views of AltEnergyMag
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