What is Renewable Energy? In todays 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.
Content of renewable energy Solar energy Wind energy Hydro energy
Solar energy What is solar power? Different method of generation Application Advantage Disadvantage
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 photovoltaics, solar thermal electricity and solar architecture, which can make considerable contributions to solving some of the most urgent energy problems the world now faces.
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.
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 . 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.
Application For home appliance Industries In feature for car Heating purpose
Advantages The suns 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.
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
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.
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 . 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
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.
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 
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 countrys 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".
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.
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.
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.
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.
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
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
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.