Energy & Society
Man lives in a community and every community needs energy in one way or another to be able to survive, hence there is need to develop energy for better use in the community. Man requires energy to drive the cars and lorries, light the streets and homes, as well as to power air and sea transport.
Sources of Energy
Energy sources are divided into two namely:
- Renewable energy source
- Non-renewable energy source
These are sources are the energy that can be replenished or replaced by nature: examples are
(i) Biomass fuel: these are energy derived from living things living or dead and are used as fuel e.g. wood, charcoal, biogas.
(ii) Wind power: Energy from the wind is used by windmills to turn generators in producing electricity.
(iii) Hydropower: Water from huge height or top of a mountain can be made to fall to turn turbines in generating electricity.
(iv) Wave and Tidal: Energy of tidal waves can be used to turn large turbines, to generate electricity.
(v) Solar energy: Energy from the sun can be trapped to generate electricity.
These are sources of energy that cannot be replaced when used up. Examples are:
(i) Fossil Fuel: These are energy stored in fossil fuels of plants and animals that are buried under the earth million years ago. This stored chemical energy is converted into heat energy when burnt.
(ii) Nuclear Fuel: These are energy emitted from radioactive elements. The nuclei of the atoms release a large amount of energy when they undergo fission or fusion, these energy are converted into useful means such as electricity.
Forms of Energy
Energy exists in different forms and according to the law of conservation of energy. It states that energy can neither be created nor destroyed but it can only be transformed from one form to another. A Car uses petrol as a means of energy to move from one point to another. Also, an electric heater converts electrical energy to heat energy for heating and cooking. Other energy conversions are:
- Sound energy to electrical energy and back to sound e.g. telephone.
- Electric energy to light and sound energy e.g. television or radio
- Chemical energy to electric and light energy e.g. cells and battery
Mechanical energy: kinetic and potential energy e.g. waterfall converts potential energy to kinetic energy.