“Energy”, one of the most important necessities worldwide. There are a lot of ways to generate energy, creating energy through sun is termed as “Solar energy”. To generate energy from sun we use solar cells, solar modules and solar panels, and what are all these different terms? Well… Solar cells are often bundled together to make larger units called solar modules, and solar modules coupled into even bigger units known as solar panels. When the sun light falls on a solar cell, electric energy is generated!
Firstly solar panels harness solar energy from the sun in individual solar cells. The energy is then transferred to an inverter which converts it to electricity, suitable for use in your home.
A semiconductor material such as silicon absorbs particles of light when the sun shines on the photovoltaic cells (PV cells) within solar panels. Particles of electricity (electrons) which are negatively charged, begin to flow through the solar cells in a single direction, which means that a current is created. The solar panels are constructed from a series of interconnected cells.
Is it that simple? Well.. Actually a lot is happening inside the solar panel, that is what we are gonna see now.
Solar cell is made of? Solar cell is a sandwich of two different layers of silicon. Why silicon?? To know why, first we need to understand a few terms. Conductors: These conductors conduct electricity.. Insulators: Other materials, such as plastics, wood etc… Don’t really conduct electricity at all.. Those materials are called insulators. Now Semiconductors like silicon are neither conductors nor insulators, they only conduct electricity under certain circumstances. Those are the circumstances we are interested in, now.
This silicon is actually specially doped, That is the “circumstance” we need to let electricity flow through them in a particular way. The lower layer is doped such that it has very few electrons. It’s called p-type or positive-type silicon, Why positive? Because electrons are negatively charged and this layer has too few of them. The upper layer is doped in the opposite way to give it slightly too many electrons. It’s called n-type or negative type silicon.
Now, if light (made of photos) falls on the solar panel, that is on the silicon cell with a sufficient amount of energy to knock out the electron from its bond. A hole is formed. And as the electron is negatively charged, the electron goes to the n-side and the hole goes to the p-side. These freely moving electrons are collected, through which an external circuit is powered…
The power generated through these solar panels is DC (Direct current). Our homes run on AC, not on DC power. The inverter changes DC to AC or alternating current.
Each silicon cell can generate only half a watt of power, which is very less.. But when, these solar cells are combined to form a solar module, the power generated is high. It is even higher in the case of a solar panel. And there is nothing wasted in a solar cell except the never ending energy emitted by the sun, so these solar panels can sustain for decades.
There is a lot of “clean” and infinite energy coming from the sun, if we could be able to make use of it, there won’t be any energy crisis anytime soon.