05 Jan 2008 |
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Rural Electrification and Energy Sufficiency: Matters arising Christopher Odetunde, Ph.D.* Most developed countries see African nations as merely dumping grounds for products and for some untested energy policies in areas of agriculture, energy, education, medicine to mention but a few areas. This fact is also reflected by African consumerism policies in the areas of Agricultural, energy and educational, healthcare, etc. I subscribe to the school of thought that believes that an African nation that defies this label would ultimately end up controlling larger share of the African and even global market. A stable energy drives industry, improves and encourages research activities, promotes standard healthcare delivery system that is technology driven, provides, in some sense, reduced conflict because a free people are self sufficient; free people have fewer conflicts; free people have sound political system that reflects peoples’ needs and more importantly, sound educational system that is compatible with the world’s best. Energy is one of the most important ingredients for building a nation’s infrastructure and brings about radical increase in industrial capacity utilization. The classical definition of energy, energy is the ability to do work through motion, or through transferring of heat. In thermodynamics, work is seen as a process of energy transfer. Energy can be transferred through heat flow such as when we put a pot of water on the range/stove. The water gets hotter due to its molecular agitation and increased vapor pressure. Not only does water get hot, the pressure generated by a change in molecular state (steam) can cause the cover to move. In this article, we’ll consider three types of renewable energies among others that are available and easily harnessed in Nigeria. They are Wind, Wave and Solar energies. We need to focus on these so that every Nigerian can begin to experiment and develop these energy types, read a little about how to size and the site wind energy machines.
WIND ENERGY We have all experienced wind blowing on our faces. What is wind? Wind is simply air in motion. Wind is caused by the uneven heating of the earth’s surface by solar system, sun. Since the earth’s surface is made of very different types of land and water, it absorbs the sun’s heat at different rates. During the day, the air above the land heats up more quickly than the air over water. The warm air over the land expands and rises, and the heavier, cooler air displaces the rising air take its place, creating what we refer to as winds. At night, the winds are reversed because the air cools more rapidly over land than over water. The large atmospheric winds that circle the earth are created in the same manner because the land near the earth's equator is heated more by the sun than the land near the North and South Poles.
Today, wind energy is mainly used to generate electricity. Wind is called a renewable energy source because the wind will blow as long as the sun shines. The way we harness wind energy is through Wind machines. Wind machines use blades to collect the wind’s (motion) kinetic energy. Windmills work because they slow down the speed of the wind. The wind flows over the airfoil shaped blades causing lift, like the effect on airplane wings, causing them to turn. The blades are connected to a drive shaft (See Figure I) that turns an electric generator to produce electricity. Because the blades are the essential part of wind machines blades design optimization determines the efficiency of a wind machine. A wind design engineer, Aerospace, Mechanical engineers, must consider what to do when wind is not blowing. During those times, other types of power plants must be used to generate electricity. There are two different types of wind machines, based on the direction of rotation. They are: Vertical and horizontal axis wind machines.
SOLAR ENERGY Solar energy
generation or Photovoltaic systems are like any electrical power generating
systems except equipment used is different from that used for conventional
electromechanical generating systems.
The principles of operation interfaced with other electrical systems
remain the same, and are guided by a well-established body of electrical codes
and standards. Although a Photovoltaic
array produces power when exposed to sunlight, a number of other components are
required to properly conduct, convert, distribute, and store the energy
produced by the array. Depending on the
functional and operational requirements of a PV system, the specific components
required may include major components such as a DC-AC power inverter, battery
bank systems, battery controller, and other auxiliary energy devices. Furthermore, other Balance of System (BOS)
hardware which includes wiring, over-current, surge protection, disconnect
devices and other power processing equipment are required to guarantee
workability of PV system. Photovoltaic power systems are generally classified according to their functional and operational requirements, their component configurations, and how the equipment is connected to other power sources and electrical loads. Generally, the two principal classifications are: a) GRID-CONNECTED, often referred to as UTILITY INTERACTIVE SYSTEMS (UIS); and b) The STAND-ALONE systems. Most privately operated PV systems are Stand-alone which are capable of generating far more than is needed and the excess can be sold when needed. A sample of a typical interactive system is shown in Figure II. For further interest in solar power generation, reader can contact professionals and companies that deal in solar systems. It must be stated here that clients can buy off the shelf solar system but they need to be warned that such systems are specific and may no meet their energy needs. Ocean Current and wave Power The latest research in renewable energy is the
ocean current and wave power with either high head/low volume or low head/high
volume. The fluid induction power system
combines: a) Attributes of turbine technologies; b) Positive displace crossflow
hydro turbines; c) Multi-stage; and Multi-port. Ocean current and wave
technology have environmental advantages especially in the developing world
where pollution is rampant and less technology to combat it. The advantages of ocean power technologies
are: a) Reduction and in some cases elimination of for dams or reservoirs; b) They add more capacity to
existing hydroelectric facilities in order to reduce need for power generated
by other means such as coal, natural gas or petroleum; c) They cause Minimal
appearance and changes in the environment; and d) They cause reduction in air
pollution, and reduction in fuel consumption. This new technology ventures have: Low capital costs; system faster coming online; Low operating and maintenance costs; back online quicker if down - swap out containers Helicopter into mountainous regions and they support green power ideas in that they have less environmental impact than conventional hydropower systems. Nigerian government or rich Nigerians looking for where to invest need consider investing in this area of new technology because research, development and renewable energy are moving forward.
igure 3: Ocean Current and wave Power Nigeria’s energy problem can be solved through concerted efforts and by bold steps not by Federal but by State governments. In other words, many Nigerian scientists understand how to generate energy if government encourages them. They can put their knowledge to use for Nigeria but, so far, Nigeria is still in the 18th century with respect to energy because each successive government tells citizens that the enemies will not allow them to make a difference, unfortunately, our nation is in the 21st century in energy usage.
Now, I believe it is time
to refocus on renewable energies such as Wind, Solar, Hydro, Ocean and wave
power and Biomass through a true genuine rural electrification strategy. Each Nigerian state should challenge their
university Dons, and their scientists both in Nigeria and in Diaspora. It is only when home grown scientists are
encouraged that energy will be stabilized, industries will grow, cooperation
among Nigerians would be established, and food would be surplus for internal
consumption and for exporting. States
that produce surplus energy can sell to the state that is not able to produce
enough for her citizens through utility Interactive system. Time for seeking expatriates to do the
nation’s initial bidding is over, it is time for Nigerian professionals to
answer the nation’s technological call and for the servant leaders to challenge
and demand accountability of performance, deliverables and meeting key established
milestones from the nations’ professionals. _____________________________ * Christopher Odetunde is an Aerospace/Mechanical Engineer and a renewable professional with ABCON Global Energy Global, Inc.
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