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What is Solar Energy?Normally the two forms of Energy,Light and Heat from Sun,refers to Solar Energy

Sunlight is a renewable Energy source which does not have harmful emissions And above all it is free

The use of Solar Energy has not been opened up because the oil Industry does not owe the sun

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The Sun is a unique and clean source of free power

On a bright sunny day,the Sun delivers more than 1000 kWh of Energy per square meter to Earths surface,

It is better to know that 1000kWh is the energy found in nearly 100 liters of fuel oil

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Solar Modules as known as Solar Panels can convert Sunlight in to usable Energy.

A set of Solar Modules is called a Solar Array

Solar Thermal Modules convert Sunlight into Heat while Solar Photovoltaic(also known as PV) Modules turn it into ElectricityHere we talk aboutConversion of Sunlight toElectricity

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Lets see How it is converted

When Solar Panel is exposed to sunlight ,it absorbs some of the energy in sunlight and use it to free electrons,then they start to flow.

When we manipulate this flow of electrons in a uniform manner,we can have a flow of useful direct current(known as DC)

Here,we consider about Solar panels made out of Silicon,which is a semi-condutor material,

Si is somewhat special regarding its electric conductivityits worth talking about

Silicon has 4 electrons in its outer energy level.

Naturally Silicon is found in its crystalline form ,in it each Si atom is bound to another four Si atoms by valence bonds formed using these four electrons,pairing with other electrons from the other Si atoms

At room temperature Si is not a good conductor of electricity,so considering its position in the periodic table,Si is doped by using B and P and a good conductivity is gained.

When it is B which is used to replace some Si atoms in the crystal structure,as B has only 3 valence electrons there is a lack of one electron to make one of the four bonds with other 4 Si atoms,

This lack of electron is called a Hole.

And when P is used, as it has 5 electrons in the valence shell,it has an extra electron to make a bond

So what is gained with B is called a P-type semi conductor and with P it is a N-type semi conductor

The extra electron found in Extrinsic Si semi-conductor

And then we let P type and N type semi conductor layers to contact with each other,Something interesting happensAs all the electrons are free to moveHoles and electrons start to diffuse through The two layersand once those electrons Have find openings they fill-up,

Then those atoms with excess electrons become Negetively charged while the atoms those who loose the electrons become Positively chargedAnd then,it forms an insulating layerBetween the N and P regions,making it difficult to other Charges to diffuse through the interface

Due to the ions besides the insulating layer An electric field is formed,So,when light photons fall on this semi conductorIt makes new electron hole pairsAnd these charges are moved to two sides due to the electric field.

A photon has exactly the energy needed to free one electron from its bondTiny Energy packets - PhotonsE = hfE Energy of the Photonh Planks constantf Frequency of the Photon

So,when an electron is made free by a photon,it is pushed into the N type region by the electric fieldlikewise many electrons are pushed,

The n type region becomes more negative while the P type region becomes more positive

Now,if we can find an extra current path,like a wire conecting N and P type regions,all the electrons will pass through it, making an electric current that we can use

Load Resistor(Home/Office Appliances)

Then we can pass it through any sort of resistor or can convert it to AC Solar panels are more effective in direct and intense sunlight So,in countries that experience intense sunlight ,using PV modules are becoming a cost-effective way to generate Electricity

What is an Inverter?An Inverter is an electrical device which converts Direct Current into Alternating CurrentWhy Inverter?Earlier,AC to DC converting devices were known as Converters,and devices which could be made to run backwards,converting DC to AC,were known as Inverters

It is just like thisCentre Zero Galvenometer

Net Metering

The whole thing we talked about in a simple manner

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Above shown photo is a set of Solar Arrays in a Solar Power Plant

Solar energy is largely used in European region and USA ,even with low intensity in sunlight

Sri Lanka is near the equator,and here we have plenty of sunlight

So we are lucky enough to use them so effectively,as we experience intense sunlight throughout the year

So,Wouldnt it be Wonderful if we use the Energy from the Sun

THANK YOU!