Page 16 - Primary Seven Notes

Importance of wind

 Used for winnowing

 Used to turn wind mills to produce electricity.

 Used to sail boats

 Helps to disperse seeds

 Used in pollination.

 Used to fly kites.

 Speed up evaporation and hence increases the speed to dry
things.

 Plants (wood fuel, food) as energy resources.

Biogas

What is biogas?

Biogas is a type of fuel that is naturally produced from the de-

composition of organic waste. When organic matter, such as

food scraps and animal waste, break down in an anaerobic en-

vironment (an environment absent of oxygen) they release a

blend of gases, primarily methane and carbon dioxide.

The gas is called biogas because it is produced using
materials fromliving things. These can be dead or¬

ganisms, dead parts or wastes, materials such as cow

dung, plant materials and animal urine.

Other than disposing of such materials, we can use

them profitably to obtain biogas.