Social Studies

1. ENERGY4th form Social Studies

4. ENERGY DEFINED
• Energy is the power which a body or system possesses for doing work.
Note:
Man has a natural source of energy which he uses everyday for doing work. To
perform any activity even as simple as moving a finger, walking, a man requires
energy.
However,
To develop a country, man needs a greater source of energy.
For this reason, we use a variety of non-human sources.

5. SOURCES OF ENERGY
• Fuel wood
• Natural gas
• Hydroelectricity
• Oil
• Coal
• Nuclear

7. WHY WE NEED ENERGY
• The level of the world’s economic development depends to a large extent
on man’s skill in harnessing energy sources as cheaply as possible.
Note:
This is especially true in this highly technological era because industries
cannot expand if energy sources are too expensive to exploit.

8. FORMS OF ENERGY
Energy comes in three forms:
1. Fossil fuels (coal, oil and natural gas)
2. Nuclear power
3. Renewable energy (hydro electric power, thermal and solar energy,
wind power and tidal energy).

9. FUELS
• A fossil fuel is a fuel that is formed from the remains of dead plants and animals.
Example: coal, oil and natural gas (non-renewable resources)
Note:
• These account for over 72% of all energy used.
• Responsible for the man-made increase in carbon dioxide which contributes to global warming.
• Petroleum (crude oil) is the most widely used form of energy.
• Petroleum is used in the home, agriculture, transportation, communication and industries etc.
• Trinidad and Tobago in the commonwealth produces petroleum and natural gas in substantial
qualities.

10. PETROLEUM AND NATURAL GAS
Petroleum
• Liquefied petroleum (LPG) is
manufactured.
Natural gas
• Occurs in underground formations

11. NUCLEAR ENERGY
• Nuclear energy is stored in the nucleus of atoms and the energy is released by splitting the
atom. Uranium is mainly used in this process. A great deal of energy is released by this
process.
• Fission, which produces energy for electricity, takes place in a specially constructed nuclear
reactor.
Nuclear energy is used mainly for:
1. Generating electricity
2. Propelling ships and submarines
3. In medical treatment (cancer)
4. In research (x-rays)
5. Defence purpose (nuclear weapons)

12. NUCLEAR ENERGY
Opposition to the use of nuclear energy stems from the dangers of
being exposed to radiation which can result in brain diseases, cancer,
leukemia, sterility, aging and anaemia.
There are also problems related to the disposal of radioactive waste.

13. RENEWABLE ENERGIES
Solar energy, Hydroelectric energy, Tidal energy, Geothermal energy, Wind energy

15. RENEWABLE ENERGIES
 Renewable energies are sometimes termed renewable source of energy.
Sources of renewable energies include the sun, water, underground heat,
wind and biomass.
 Renewable energy supply more than 18% of world demand, more than
nuclear power.
 These are the more expensive source of energy for commercial use. Also, the
building of dams and wind farms causes environmental damage.

16. SOLAR ENERGY
 Solar energy is energy from the sun.
 Solar energy can be harnessed directly in the form of heat or
converted into electricity.
 In the Caribbean, solar energy is restricted to water heating
and crop drying.
 In other countries, it has been used for spacecraft, motor
vehicles and heating buildings.

17. HYDROELECTRIC ENERGY
• Water has been a traditional source of energy to turn
mills, and water wheels to irrigate fields.
• Today, water is an important source of energy used to
generate electricity.
• Hydroelectric power plants use the energy of moving
water in rivers or waterfalls to produce electricity.
They are built as part of dams on rivers.
• The main disadvantage of hydroelectric power is that
several of the best sites are too far from populated
areas which needs dams the most.

18. TIDAL ENERGY
 Tidal energy is created by the rise and fall of tides and is used to produce
electricity.
 Tides are caused by the gravitational pull of the moon and the sun on
earth, causing the level of the oceans to change.
 The energy of the tides are derived from kinetic energy of water moving
from a higher to a lower elevation.
 The major problem associated with this source of energy is that there are
very few sites where the tides are high enough or low enough to make the
investment worthwhile.
 No use has been made of this source in the Caribbean.

19. GEOTHERMAL ENERGY
 Geothermal energy makes use of underground heat, which increases
with depth. It allows a turbine to be driven by water or steam produce
electricity. It is used in Iceland, New Zealand, Italy and Japan.
The use of geothermal resources depends on:
• Energy demand and cost
• Environmental constraints
• Availability of energy sources
• Social benefits
The major uses of this energy in the future would be for:
• District heating
• Industrial processes
• Agricultural processes
• Food processing.

20. WIND ENERGY
 Wind is air in motion.
 Windmills were once used for grinding corn, cutting timber and
pumping water.
Two types of energy systems are associated with this system:
1. Grid connected system based on a standard type of wind turbine,
which produces energy directly to large electric grids and where only
a relatively simple control system is needed.
2. Wind/diesel system which is a hybrid system of a wind turbine and
conventional diesel generator.