1. What is Renewable Energy?
In today's climate of growing energy needs and increasing
environmental concern, alternatives to the use of non-renewable
and polluting fossil fuels have to be investigated. One such
alternative is renewable energy.
Renewable energy is energy that comes from resources which are
continually replenished such as sun light, wind, rain, tides, waves
and geo thermal heat.
3. Solar energy
What is solar power?
Different method of generation
Application
Advantage
Disadvantage
4. What is solar power?
Solar energy, radiant light and heat from the sun, has been
harnessed by humans since ancient times using a range of ever-
evolving technologies. Solar energy technologies include solar
heating, solar photovoltaic's, solar thermal electricity and solar
architecture, which can make considerable contributions to solving
some of the most urgent energy problems the world now faces.
5. Different method of generation
PHOTOVOLTAIC CELL :-
When light enters the solar cell and is absorbed in the semi-
conductor sandwich, an electron is freed. If this electron is close
enough to the boundary of the two semi-conductors, it is attracted
across the boundary by the fixed electric field. The movement of the
electron across the boundary causes a charge imbalance in the
semi-conductors. The semi-conductors naturally want to get rid of
this charge imbalance. However, the electric field works in only one
direction and thus prevents the electron from re-crossing the
boundary, so if it is to return, it must travel through an external
circuit - thus we have electricity.
9. Component require for solar energy
The major components include P.V modules, battery and inverter.
The most efficient way to determine the capacities of these
components is to estimate the load to be supplied. The size of the
battery bank required will depend on the storage required, the
maximum discharge rate, and the minimum temperature at which
the batteries will be used [4]. When designing a solar power system,
all of these factors are to be taken into consideration when battery
size is to be chosen.
Lead-acid batteries are the most common in P.V systems because
their initial cost is lower and also they are readily available nearly
everywhere in the world.
Deep cycle batteries are designed to be repeatedly discharged as
much as 80 percent of their capacity and so they are a good choice
for power systems. Figure 2 is a schematic diagram of a typical
Photovoltaic System.
11. Advantages
The sun's energy is free to use, which makes the process cheaper.
The process is completely non-polluting.
Can be used in a wide variety of locations the world over. Wherever
there is sun.
12. Disadvantages
Cost of the panels and equipment is expensive. This will, however,
become cheaper in time.
Can only work when the sun is available; therefore weather
dependant
13. Wind Energy
Wind power is when we covert the power of the wind, physical
energy, to more useful types of energy. The most common type of
energy it is converted to is electricity.
A wind farm is a large area of land on which there are a number of
wind turbines generating electricity, as a power plant does. When
creating a wind farm one must make sure that the spacing between
the turbine is sufficient as not to cause energy/wind loss.
14. Working of wind machine
Wind Power is energy extracted from
the wind, passing through a machine
known as the windmill. Electrical
energy can be generated from the
wind energy. This is done by using the
energy from wind to run a windmill,
which in turn drives a generator to
produce electricity [6]. The windmill in
this case is usually called a wind
turbine. This turbine transforms the
wind energy to mechanical energy,
which in a generator is converted to
electrical power. An integration of wind
generator, wind turbine, aero
generators is known as a wind energy
conversion system
15. Yes, as we find wind throughout the world and the
minimum wind speed needed is from 16km/h upwards.
The wind needs to have a constant speed, should be
non-turbulent and must not be subject to strong bursts of
air. The wind also blows faster the higher into the
atmosphere you go. That is why most wind farms are
found quite high up.
A tower on which the wind turbine is mounted;
A rotor that is turned by the wind;
The nacelle which houses the equipment, including the
generator that converts the mechanical energy in the
spinning rotor into electricity.
16. Wind turbine
A wind turbine is a machine for converting the kinetic energy in wind
into mechanical energy. Wind turbines can be separated into two
basic types based on the axis about which the turbine rotates.
Turbines that rotate around a horizontal axis are more common.
Vertical-axis turbines are less frequently used [8,9].
Wind turbines can also be classified by the location in which they
are used as Onshore, Offshore, and aerial wind turbines [9]
17. Advantages
Wind is free and in abundance and we have the technology to
capture the power of wind efficiently
The costs for wind turbines are only initial costs; once the turbine is
built there are minimal maitenence costs which are involved.
In the rural areas which are not connected to a country's power grid
it can be used to generate its own power.
The space which a wind turbine takes up on land is very small as
the moving parts are quite a distance above the ground.
Wind turbines produce energy with minimal damage to the worlds
environment and produces "clean power".
18. Disadvantages
Some pollutants are given off into the atmosphere in the creation of
a wind turbine.
Wind turbines can be quite noisy.
The wind speed is not constant and therefore there will not always
be a definite supply of electricity form a wind turbine.
Large numbers of wind turbines are needed to power towns, as the
largest turbine is able to produce electricity to sustain only +/- 500
homes.
Many people feel that wind turbines are unsightly and that they
should not disrupt the natural beauty of landscapes.
19. Hydro Energy
Hydro power is the process of changing the kinetic energy of flowing
water in a river into electrical power that we can use.
A dam is built where there is a natural lake or a big river in a valley.
The dam is used to hold the water and create pressure so that the
water can produce more electrical power. There is gravitational
potential energy stored in the water and this energy is used to turn
generators and create electricity. These turbines are within tunnels
in the dam wall. Electrical generators are turned by these massive
turbines and create electricity. Water flows through these tunnels
with great pressure and is used to turn these turbines. The water
has immense pressure due to the great height at which is kept in the
dam. If there is a greater volume of water or there is a very large
difference between the water level and where it flows out than you
can get more power out of the water as it has greater potential
energy.
22. Is it renewable??
It is renewable because the process
takes nothing away from the
environment and therefore nothing
needs to be replenished. The water
stays in the water cycle and can keep
producing energy endlessly.
23. Application of hydro energy
Hydro power is also utilised by large scale companies as a private
use. Many large mining companies or aluminium manufacturers use
vast amounts of electrical so rather than buying from the state they
can generate their own power by using hydro power generation.
24. Advantages
No pollution or waste produced
Renewable energy source
Very reliable energy source
Not expensive to maintain once the dam has been built
Can increase the plants production or decrease it whenever there is
high or low demand
Water can be stored, waiting to be used in peak times
25. Disadvantages
Building the dam is expensive and time taking
The dam will change the habitat and landscape upstream, as much
more land will be submersed
The land below the dam is also affected as the flow of water is
reduced
Silt can build up in the dam as the water slows down it does not
have enough energy to carry the sand and silt which it was
26. Conclusion
There is the need for the provision of an alternative sustainable
electric power supply system to provide electricity to rural and the
unreached communities. The importance of Information
Communication Technology for e-service to rural communities are
inevitable in order to achieve the MDGs objective. Also there is the
need for rural banking and hospitals if the social and economic lives
of rural citizens in Nigeria are to be improved.
The provision of hybrid solar -wind energy system to power ICT
infrastructures, banking and hospitals in rural and the unreached
communities that are not connected to National Grid Power supply
system is very important so as to maintain a continuous electricity
supply.
When considering the cost and overall efficiency, it is advisable for
all the stakeholders who have concern for the rural community
development to embrace solar and wind power.
