Lesson Notes By Weeks and Term - Junior Secondary School 3

SUBJECT: BASIC TECHNOLOGY   

CLASS:  JSS3

DATE:

TERM: 3RD TERM

Reference Materials:

1. EVANS, Introductory Technology For JSS, Book 3.
2. NERDC, Introductory Technology For JSS, Book 3.

Week 3

TOPIC: ENERGY SOURCES- WINDMILL             

CONTENT 

• Wind energy
• Windmill 
• Windmill power plant  

WIND ENERGY

Wind is another form of energy just like the solar radiation beamed from the sun, the water behind a dam, the stored energy in fuel.

When wind blows through open windows and doors into our rooms, we sometimes notice that ceiling fan can start to rotate even though it is not switched on. 

Children make propeller with paper and broom stick. The blades revolve freely on the main shaft. As you hold the ma in shaft in your hand and run fast, the blades rotate at a speed that depends on how fast you can run.

Evaluation 

1. Define wind energy
2. Demonstrate the power of wind energy.

Thus, if a propeller with the blades firmly attached to its main shaft is installed on top of a mast. When the wind blows, it will rotate the blades and hence the shaft to which they are firmly connected. Thus, this system has converted the wind energy to the mechanical energy of the rotating blades and the shaft. Such mechanically energy can be used directly for grinding, pumping water e.t.c. To generate electricity, the above system is joined to an electric generator, which converts its mechanical energy to electrical energy.

Evaluation 

1. Explain how wind can be classified as a renewable energy source
2. Give practical examples that proved that wind could be strong.

How to generate electricity using a windmill

Wind mill receives its source of energy from the wind blowing. Therefore, the blades of the windmill must be placed in such a way it come receive maximum wind. The blades begin to turn converting the wind energy to mechanical energy. A turbine-generator is connected to the blades by a drive mechanism. The generator, will in-turn, produce electricity.      

Evaluation 

1. State the important components of a wind power plant
2. Briefly explain the operation of a wind power plant

Reading Assignment 

Read “RENEWABLE ENERGY –WIND ENERGY”

Reference Materials:

• EVANS, INTRODUCTORY TECHNOLOGY FOR JSS, BOOK 3, pages 191-192

Weekend Assignment 

1. A windmill converts the kinetic energy of wind into the ___ of a rotating shaft (a) mechanical energy (b) solar energy (c) nuclear (d) wind energy
2. Energy from the windmill can be used for the following except (a) grinding (b) pumping (c) generating electricity (d) ploughing
3. The speed of the shaft of a windmill depends on the (a) length of the shaft (b) strength of the wind (c) power of the turbine (d) solar energy 
4. When the wind blows, the blade will (a) rotate  (b) revolve (c) slant (d) slope
5. Generator converts (a) electrical to mechanical energy (b) mechanical to electrical energy (c) kinetic to potential energy (d) electrical to potential energy

Theory 

1. Briefly explain wind energy as renewable energy source
2. Describe how windmill can be used to generate electricity.