Page 161 - CITS - Electronic Mechanic - TT - 2024

ELECTRONICS MECHANIC - CITS

MODULE 9 : Solar power (renewable energy system)

LESSON 90 - 93 : Solar power

Objectives

At the end of this lesson you shall be able to:
• state the need of solar power
• explain principle involved in solar cell
• difference between conventional & non- conventional sources opf energy.

Solar power

Need for Renewable energy
Renewable energy is energy derived from natural sources that are replenished at a higher rate than they are
consumed. Sunlight and wind, for example, are such sources that are constantly being replenished. Renewable
energy sources are plentiful and all around us. Fossil fuels - coal, oil and gas - on the other hand, are non-
renewable resources that take hundreds of millions of years to form. Fossil fuels, when burned to produce energy,
cause harmful greenhouse gas emissions, such as carbon dioxide.
Generating renewable energy creates far lower emissions than burning fossil fuels. Transitioning from fossil fuels,
which currently account for the lion’s share of emissions, to renewable energy is key to addressing the climate
crisis.
Renewables are now cheaper in most countries, and generate three times more jobs than fossil fuels.

Material used for solar cell
The metal that is highly used in solar cell is silicon as it shows the properties of a semiconductor. Cesium metal
is also used in making solar cell due to its low ionization energy and it can easily convert sunlight into electrical
energy.
A Solar panels (also known as “PV panels”) is a device that converts light from the sun, which is composed of
particles of energy called “photons”, into electricity that can be used to power electrical loads.

Solar panels can be used for a wide variety of applications including remote power systems for cabins,
telecommunications equipment, remote sensing, and of course for the production of electricity by residential and
commercial solar electric systems.
Working Principle of Solar Cell: When light reaches the p-n junction, the light photons can easily enter in the
junction, through very thin p-type layer. The light energy, in the form of photons, supplies sufficient energy to the
junction to create a number of electron-hole pairs.

146