Class: JSS 1
Topic: Energy and sources of Energy
What is energy ?
Energy is the capacity of a physical system to do work. There are two main types of energy:
- Potential (Stored)
- Kinetic (Working)
Sources of Energy
Energy can be categorized into:
- Renewable energy
- Non renewable energy
Renewable: These are energy source that can be easily replenished
Nonrenewable: These are energy source that cannot be easily replenished
Renewable and nonrenewable energy sources can be used as primary energy sources to produce useful energy such as heat or used to produce secondary energy sources such as electricity.
There are five main renewable energy sources:
- Solar energyfrom the sun
- Geothermal energyfrom heat inside the earth
- Wind energy
- Biomassfrom plants
- Hydropowerfrom flowing water
Examples of energy use:
- When we eat food, our body uses (chemical) energy embodied in the food to move around.
- When we switch on the TV, electricity (kinetic energy) is used to create the picture on the screen and the sound.
- Most of the electricity produced in the world comes from the chemical energy released in the burning of coal, oil or gas.