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As you know, electricity is an extremely important and indispensable thing in today’s modern life.
There are many types of energy that can generate electricity to serve human life, for example, using water power or hydroelectricity, thermal energy (coal, gas) or thermal power.
There are also some types of clean energy, which do not affect the environment and human health, such as wind energy and solar energy.
For energies like water and wind, you already know how it works, right? People use the flow of water or wind to turn a turbine, thereby generating electricity.
However, for electricity generated from solar energy, not many people know about how it works.
If you are also one of those people who do not understand how solar cells work, let me explain in today’s article! Okay, let’s cmn gooo…
#first. History of the formation of solar cells
Solar energy is a huge source of energy and shows no sign of being exhausted, it has existed for millions of years along with the development of the earth.
And if the sun goes out, human life will also end, so it can be said that solar energy is eternal for people and things.
Every day the earth “collects” a lot of energy from the sun, according to scientists they estimate about 173,000 Terawatts (each 1 TW = 10^12 W).
Yes, it’s really a terrible number, isn’t it, it’s a source of energy 10,000 times greater than the needs of humans on earth to use.
That is to say energy from the sun is a huge, clean and always free energy source. Therefore, the exploitation of solar energy has been applied by humans for a long time.
In the 7th century BC, people knew how to use the heat from the sun to make fires thanks to magnified glass materials.
In the 3rd century BC, the Greeks and Romans used solar energy to light torches for religious ceremonies.
And the most prominent is still Acsimet’s invention when using a mirror to focus sunlight to burn enemy ships.
It was not until 1883 that the first solar panel was invented by Charle Fritts.
Thanks to the photoelectric effect discovered by Alexandre Edmond Becquerel – a French physicist in 1839. However, the efficiency of the battery is only 1%.
Although the efficiency is still low, this is a very important milestone, laying the foundation for the future development of the solar power industry.
#2. Working principle of solar battery
To convert solar energy into electricity, in solar panels, there are smaller parts, called photovoltaic cells, that are assembled together.
These photovoltaic cells used energy from light to convert into electricity.
There are many types of photovoltaic cells, but the most common type is made from a material found almost everywhere on earth, which is Sand.
To be used as photovoltaic cells, sand must be converted into silicon crystals (also known as silicon) with a purity of almost 100% (about 99.99%).
So the question now is how can photovoltaic cells convert light into electricity?
After creating pure silicon, people need to add some impurities in a reasonable ratio, we will get 2 types of semiconductors:
N and type
For those of you who don’t know what a semiconductor is, it’s a substance that can conduct electricity, but sometimes it doesn’t, depending on the circumstances.
- N-type semiconductor: Is a type of semiconductor doped with some impurities to create unstable electrons that can be separated from the bond, and form free (e) electrons => excess (e). In short, N-type semiconductors have free electrons and carry a negative (-) charge.
- P-type semiconductor: Also silicon is doped with other types of elements, but these added elements will create a lack of electrons and the places where the electron is missing are holes, carrying a positive (+) charge.
When these two types of semiconductors are combined, the free electrons from the .-type semiconductor WOMEN will combine with holes in .-type semiconductors P => this will create poor area between, and the poor region close to the N-type semiconductor will carry a (+) charge, and the poor region close to the P-type semiconductor will carry a (-) charge.
=> Thus, the two sides of the poor region will create a small electric field (negative side, positive side).
Under normal conditions, the electrons of the N-type semiconductor and the holes of P will combine with each other and are difficult to separate.
However, if there is sunlight coming in, it will be different…
Because sunlight will bring photons shot in, through the semiconductor WOMEN and cause the electrons to bounce out of the hole, the ejected (e)s will move towards the N semiconductor due to the action of the electric field in the poor region, while the hole moves in the opposite direction (towards the semiconductor). lead P)
=> At this time, the N semiconductor layer will have a lot of free (e) free, and the P semiconductor layer will have many holes.
Then if we connect the light bulb to the photocell, the e from the end of the N-type semiconductor will move through the bulb and reach the hole at the other end of the P-type semiconductor. From there there will be an electric current. run through the bulb, and make the light on.
However, each photovoltaic cell can only produce 0.5V voltage, so people will connect many of these photovoltaic cells together to get a higher voltage.
Although it is an abundant and free source of energy, according to statistics, in the world today, solar energy contributes to the total electricity energy worldwide only 3%. A really very modest number !
So what prevents us from being able to use this free resource?
#3. Solar batteries are difficult to use
Partly because solar energy is not evenly distributed on earth, moreover, solar energy is also unstable. Specifically, when it is raining, cloudy or dark, there will be little or no electricity generated.
Therefore, if we want to use it stably, we will need to have a huge energy storage source, so that when needed, it will be used, otherwise, it will be stored there. But it’s easy to say, hard to make new @@, to build storage stations like this is not easy.
And another problem is that the cost of installing a solar power system is also very expensive. Although it is known to be environmentally friendly and is a free resource, the conversion efficiency from sunlight to electricity consumption is so low that it is difficult to make a mass replacement.
That’s how I helped you understand Working principle of solar cell, as well as how solar cells convert sunlight into electricity.
Hope the information in this article will be useful to you. Don’t forget to rate the article 5 stars if you find it useful to you ^^
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