Energy Energy is the capacity for doing work. Or the power required on carrying out activity. Power Is the rate of doing work. Or the rate of using energy.
You must have energy to accomplish work. Therefore, you need energy to produce power. Without energy there is no power that can be produced.
The Major Sources of Power and Energy Energy sources can be sub-divided into two broad categories. These are renewable and non-renewable energy sources. Renewable sources are those that do not get finished or used up since they are naturally replenished.
These include sunlight, water, geothermal steam, wind and biomass. Non-renewable sources are those that can get finished or used up through use, that is, they cannot be replaced once used up. They include coal, petroleum, natural gas, groundwater aquifers, and nuclear energy sources such as uranium and plutonium.
The Origin of Different Types of Energy and Power Sources Some of these energy and power sources are discussed in details below:
Coal: Coal is a fossil fuel that forms when dead plant matter is converted into peat, which in turn is converted into lignite, then sub-bituminous coal, after that bituminous coal, and lastly anthracite. This involves biological and geological processes that take place over a long period of time. Coal is black or brown in colour.
Sunlight: The sun is a source of sunlight and all forms of energy on earth. Sunlight can be harnessed to generate electricity (solar power). This is achieved by using solar panels which absorbs the solar energy, converts it into electrical energy and stores it for later or immediate use. Waves and tides: Waves are generated by wind passing over the surface of the sea, ocean or lake. As long as the waves propagate slower than the wind speed (just above the waves), there is an energy transfer from the wind to the waves
Wind: Wind is air in motion from low to high pressure region. Wind possesses energy which can be converted by appropriate devices, into mechanical energy, which in turn can be used to generate electricity or do any useful work. Water: Water in motion, such as waterfall or cataract, can be harnessed to generate hydroelectricity. First, the kinetic energy in running water is converted into mechanical and then electrical power.
Biomass: The term “biomass” refers to organic matter that has stored energy through the process of photosynthesis. This can be transferred through the food chain to the animal’s bodies and their wastes, all of which can be converted into energy for everyday human use through processes such as combustion.
Petroleum (crude oil): Petroleum is a fossil fuel formed from fossilised remains of plants and animals. When refined, it produces various petroleum fractions, which are put to various uses of energy generation. It can be used to power cars and many machines, and burned to produce heat and light or generate electricity.
Natural gas: Natural gas occurs alongside petroleum. The gas can be burned to generate light and/or heat and harnessed to generate electricity. For example, the natural gas from SongoSongo Island in Kilwa is expected to be piped to Dar es Salaam where it will be used to generate electricity and supplied to homes as liquefied gas to be used for heating and lighting.
Uranium: This is a radioactive element which produces tremendous amounts of energy upon disintegration (fission) or combination (fusion) of the nuclei of its atoms. This energy (nuclear energy) can be used and is being used by many countries in the world to generate electricity. Methods of Acquiring/Extracting Power and Energy
The following are different energy and power resources and the methods used to extract energy and power from these resources:
Coal: Coal is a combustive black or brownish-black sedimentary rock, usually occurring in rock strata in layers or veins called beds or coal seams. Coal is considered as a non-renewable resource because it cannot be replenished on a human timeframe.
The activities involved in generating electricity from coal include mining, transport to power plants, and burning the coal in power plants. At the power plant, coal is commonly burned in a boiler to produce steam. The resulting steam is run through a turbine to generate electricity.
Petroleum: Petroleum is a naturally occurring liquid found in rock deep in the ground. This liquid consists of a complex mixture of hydrocarbons of various molecular weights, plus other organic compounds. The energy from petroleum products is tapped mainly by burning.
The burning produces heat energy that is used for heating, lighting or doing some mechanical work (such as powering machinery, vehicles, etc). Fuel is burned in a furnace or boiler for generation of heat that is used in an engine for generation of power. Petroleum products can also be burned to generate electricity.
Natural gas: Natural gas is fossil fuel formed when layers of buried plants, gases and animals are exposed to intense heat and pressure over thousands of years. Natural gas is mined from deposits deep underground and brought to the surface. Before the gas can be used as a fuel, it must be processed to remove impurities, including water, to meet the standard of a marketable natural gas.
Energy from the natural gas is extracted through burning of the gas. This burning produces heat energy which is used for heating, cooking and electricity generation. The gas is also used as fuel for vehicles and as a raw material in the manufacture of plastics and other commercially important organic chemicals.
Water: The potential energy of dammed or flowing water can be converted into storable electrical energy. Harnessing the flowing water to power machines and mechanical processes is one of the oldest methods of power generation that is used until today. The energy in water may be tapped naturally or artificially.
Naturally, flowing water at waterfalls runs through turbines, which generate electricity. River water may also be used to run milling machines. Artificially, water may be lifted to higher points such as tanks or dams where it drops in mass, turning the turbines to generate electricity.
Biomass: Biomass is biological material derived from living things, or recently living organisms. It mostly refers to plants or plant-based materials. As an energy source, biomass can either be used directly via combustion to produce heat or indirectly after converting it to various forms of biofuel.
The biofuel can then be burned to release heat energy that is used to power machines or for heating purposes. Wood is burned directly to produce heat and/or light. Wood remains the best biomass energy source to date. Examples of wood include forest residues (such as braches, dead trees and stumps), yard clippings, wood chips, and even municipal solid wastes.
Biomass also includes plant or animal matter that can be converted into fibres, or other industrial chemicals, including biofuels. For example, gasohol is a biofuel derived from a mixture of alcohol (from sugar cane) and petrol. This is used as a fuel to run cars and machines. Rotten garbage and agricultural and human waste under controlled conditions can release biogas that can be used for heating, cooking and lighting.
Uranium: Uranium is a radioactive element. The energy from uranium is extracted through nuclear fission or fusion. Nuclear fission involves splitting of an atom while nuclear fusion involves combining two light atoms. The most commercially exploited process is nuclear fission, when the atoms and nuclei of this radioactive element split in nuclear reactors.
The process releases a large amount of energy in the form of heat. The heat released is used to boil water into steam, which is, in turn used to turn turbines to generate electricity. Solar energy: Solar energy refers to energy from the sun. This energy can be tapped and used for different purposes. Solar energy is tapped by devices called solar panels.
The energy is absorbed by the panels and converted into electrical energy that can be used immediately or stored for later use. The trapped energy can be used to light homes and power gadgets such as phones and calculators. The heat from the sun can also be tapped directly like when it is used to dry crops or clothes.
Geothermal steam: The geothermal power from geothermal steam is extracted by directing it to run machines that produce electricity. Its heat can also be tapped by placing the material to be heated over the hot steam. Wind energy: The kinetic energy of wind is harnessed by turning windmills, which generate electricity. Each of the several wind mills is supplied with a cable which is used to supply electricity to the main cable which then directs electricity to homes, industries etc. The electricity generated can be used for cooking, lighting and running machines. Wind energy may also be tapped by putting up sails to propel water vessels such as dhows.
The Use and Importance of these types of Power Resources
Power and energy resources are important in two ways. First, it is through the energy and power they produce and secondly, due to their own economic value.
1. The power and energy resources used in industrial development activities.
2. It used to run agricultural machinery such as tractors and harvesters such as petroleum. 3. Petroleum used by machines in agriculture increases agricultural production
4. Environmental conservation: The use of solar, wind, biogas and energy helps to conserve the environment
5. Improvement of Transportation sector because of the use of motor vehicles, ships, aircrafts, etc, all of which are powered by petroleum products.
6. Used in Mining: Most forms and kinds of machinery that are used in mineral prospection, extraction, and processing use power and energy generated from fossil fuel. Therefore, the fuel energy helps in the development of the mining industry.
7. Social services and amenities: Most social services and amenities are facilitated by energy and power. For example, sports, games, schools, healthcare, and homes depend on power and energy in different ways.
Energy and power sources have the following direct economic and social importance:
1. Source of employment
2. Source of foreign exchange
3. Source of government revenue
4. Improvement of transport and communication infrastructure
5. Promotion of trade and other industries
The Problems Facing the Process of Power and Energy Harnessing
Power and energy production endeavour is faced by a number of problems which include the following:
1. Changing climatic conditions: Drought leads to rainfall scarcity and hence a drop in the volume of water in rivers. This problem affects the production of hydroelectric power and is one of the factors leading to low energy production in most parts of the world, especially in the least developed countries.
2. Lack of capital: Energy and power production needs heavy investments in infrastructure, manpower and technology. All these investments require a great deal of capital.
3. Lack of diverse energy sources in respective countries: Most counties have very few energy resources from which to extract power and energy. Worse still, some do not have a single energy resource, so they have to import the resources or power. For instance, uranium and geothermal steam are not found in many countries. Such countries extract power from only a few available resources such as water, wind or solar energy.
4. Poor technology and lack of skilled personnel: Many developing countries lack the technology required to establish energy extraction infrastructures and the skilled personnel needed to perform that function. Most of the power and energy exploitation technology used in developing countries is very old and less efficient and productive. There are also very few people with the necessary skills for setting up and operating equipment as well as conducting research on power and energy production methods, facilities and technologies.
5. High prices: High prices for energy resources hinder energy and power output in most countries that have to import these resources from other countries. Oil is used for energy production. We have recently seen escalating oil prices worldwide. This leads to low purchase and hence low energy and power production. Also the equipment needed for production of energy and power is very expensive and can thus not be afforded by many poor countries. As a result, they resort to inefficient and less productive obsolete technology which cannot produce sufficient power and energy to meet the ever-increasing demand for energy and power.
6. Environment pollution: Energy and power exploitation is sometimes accompanied with the emission of harmful gases that pollute the environment. Coal burning, for example, releases tremendous quantities of carbon dioxide gas into the atmosphere. As such, many countries are either phasing out such energy generation technologies or spending a lot of capital to clean the coal so as to prevent environmental pollution. The power and energy production sector is, therefore, in great pressure to adopt technologies that minimize or cause no environmental pollution.
7. Siltation: Accumulation of silt in dams used for generation of hydroelectric power reduces the volume of water in dams, hence resulting to low power generation. On the other hand, removal of the silt from dams adds to the cost of energy and power production and these costs are pushed on to consumers of energy and power.
8. Scramble for resources: River water is also used for irrigation of crops, domestic and industrial uses, fishing or preservation of flora or fauna. For example, river Nile is used for irrigation in Ethiopia (Gezira Irrigation Scheme) and, at the same time, required for production of hydroelectric power at Aswan High Dam, in Egypt. If too much water is used for irrigation, little will be available for hydropower generation. This competition on the same resource can lead to international conflicts and even wars.
Another example is coal which is used for domestic heating as well as for generation of electricity. This can curtail the generation of power and energy from coal if too much of it is used for domestic heating. In Tanzania, peculiar species of toads are found at Kihanzi power generation station in Kihanzi River. Use of water for generation of hydroelectricity affects the lives of these organisms. This has caused a big concern from environmentalists and wildlife conservation groups.
Ways of Addressing Power and Energy Harnessing
1. The silt accumulating in dams should be dredged regularly in order to keep the volume of water constant. This will maintain the capacity of energy and power generation.
2. Any form of environmental pollution likely to cause global warming and reduction in amount of rainfall should be avoided. People should not cut down trees indiscriminately as this can lead to drought and hence reduction in volumes of rivers needed for generation of hydroelectricity.
3. Countries should diversify their energy generation sources in order to escape the effects caused by such problems as escalating oil prices and climate change.
4. Developing countries should phase out the old energy and power generation technologies and instead adopt the new ones so as to cope with technological advancements to ensure that their energy generation is efficient and highly productive.
5. Research should be carried out often in order to improve energy and power production, as well as come up with new production methods. Research will also help in finding power and energy production methods that cause less or no environmental pollution.
6. The governments should train their people the courses related to energy and power generation at schools, colleges, and universities so as to make them professionally competent in the field of energy and power generation.
7. Countries should set aside enough funds to be used for energy and power generation because success in this sector can boost the growth and development of other sectors. Dormancy in energy and power sector can hinder industrial development and cause the country’s economy to drop down.
The Importance of Power and Energy Resources in the Focal Countries
The USA is a technologically advanced country with a huge and very stable economy. It is a developed and heavily industrialized country with a great demand for power and energy required by its industries and its large population These and other factors have contributed to development of various power production resources. Solar and wind are among the diverse power resources in the USA.
The U.S. is among the top countries in the world in electricity generated by the sun and several of the world’s largest small-scale installations are located in the desert Southwest. Solar power includes small-scale solar power plants as well as local distributed generation, mostly from rooftop solar panels. The United States conducted much early research in solar devices and concentrated solar power. There are plans to build many other large solar plants in the United States.
Many states have set individual renewable energy goals with solar power being included in various proportions. Solar power accounts for about 1% of the total national generation capacity. It is mainly exploited in the sunny areas of the country which include Nevada and California states. Rooftop solar panels Wind power Wind power is a branch of the energy industry expanding quickly over the last several years. U.S. Wind Generation (KW) by Year Wind power accounts for 4% the total energy produced in the USA. Texas is firmly established as the leader in wind power development, followed by Iowa and California. Wind power is used to run farms, industries and for generating electricity that is fed to the national grid.
The importance of solar and wind power in the USA
1. Source of employment: Solar and wind energy industry is more labour-intensive. The industry supports thousands of people in the USA. The wind energy industry employs many Americans in a variety of capacities, including manufacturing, project development, construction and wind mill installation, operations and maintenance, transportation and logistics; and financial, legal and consulting services. The solar energy industry employs people in jobs including solar panel installation, manufacturing and sales.
2. Industrial development: The energy and power generated from resources such as coal, uranium, petroleum and water are very expensive compared to wind and solar energy. The abundance and availability of cheap energy from wind and sunlight promotes industrial development.
3. Agricultural development: Wind and solar power is commonly used in large farms to supply electricity required for such activities as pumping water, lighting and heating. This has, in turn, promoted large-scale agriculture in the country.
4. Conservation of non-renewable energy resources: Depending on renewable energy sources such as wind, solar and hydroelectricity for power and energy generation helps to conserve the non-renewable energy sources such as gas, coal and petroleum. This ensures that these non-renewable energy resources do not run out or become exhausted soon. They are conserved for future uses instead.
5. Reduced environmental pollution: Exploitation of non-renewable energy resources, such as petroleum, coal, and wood, releases harmful gases to the atmosphere which pollutes the environment. Harnessing and use of wind and solar energy do not pollute the environment. Thus, generating sufficient power and energy from these resources will help reduce environmental pollution that could otherwise result due to dependence on non-renewable resources.
6. Improved standard of living: People employed directly and indirectly in the wind and energy industry earn cash which they spend on their daily needs as well as other amenities. Solar and wind energy is cheap and hence affordable to many Americans. So, people who had no access to the costly hydroelectricity and thermal electricity are now able to use this cheap power and energy. This has helped improve their living standards.
7. Development of other sectors of economy: Growth in power and solar industry creates positive multiplier effects. For example, industries in the renewable energy supply chain, such as those manufacturing windmills and solar panels, will benefit. The growth of industries involved in the manufacture of wind and solar energy equipment depends on the growth and existence of the solar and wind generation industry. Also local businesses will benefit from increased household and business incomes.
8. Generation of revenue: Local governments collect property and income taxes and other payments from energy project owners. These revenues can help support public services, especially in rural communities, where projects are often located. Owners of the land on which wind projects are built also receive lease payments as well as payments for the rights to transmit electricity through their land. Also they may earn loyalties based on projects’ annual revenues.
9. Stabilisation of energy prices in future: Wind and solar energy is providing affordable electricity across the country right now, and can help stabilize energy prices in future. The costs of solar and wind energy technologies have declined steadily, and are projected to drop even more. For example, the average price of a solar panel has dropped significantly. The cost of generating electricity from wind is also declining gradually. The wind and solar energy projects require initial investments to build but once established they operate at very low costs and to most technologies the fuel is free. As a result renewable energy prices are relatively stable over time.
10. Diversification of energy supplies: Using more wind and solar energy can lower the prices and demand for natural gas and coal by increasing competition and diversification of energy supplies. Generation of energy from different resources ensure that the supply is not interrupted in case one resource is finished or exhausted. This ensures constant availability of power and energy. Therefore, wind and solar energy helps to diversify the energy supply in the country.
11. Reliability and flexibility: Wind and solar energy supplies are less prone to large-scale failure because they are distributed and modular. Distributed systems are spread out over a large geographical area, so a severe weather event in one location will not cut off power to an entire region. Modular systems are composed of numerous wind mills or solar panels. Even if one of the equipment is damaged the rest can typically continue to operate.
12. Sustainability: For as long as the sun shines and the wind blows, the energy produced can be harnessed to send power across the grid. The Problems Facing Power and Energy Harnessing in Focal Countries
Problems facing solar and wind power in the USA
1. Generation of wind and solar power depends on prevailing weather conditions. In case of little or no sunshine due to prolonged cloud cover or if there is very low wind speed, then very little power will be generated. This, in turn, leads to generation of little amount of electricity which cannot meet the demand of all consumers.
2. People are still reluctant to change from dependency on the traditional energy sources, such as hydroelectricity. They are, therefore, slow in adopting the use of solar and wind power, thus hindering fast development and growth of the industry. 3. The cost of installation of equipment for generating wind and solar power on a large-scale is very high. This has led to limited investment in the industry.
4. The cost of leasing land for building wing energy projects is very high. The problem has made many companies reluctant to establish wind power projects.
5. The industry is facing stiff competition from other sectors of energy and power, such as coal power, hydroelectric power, and geothermal power.
6. Unequal government subsidies and taxes. Nuclear and fossil fuel technologies enjoy a considerable advantage in government subsidies for research and development, compared with wind and solar energy counterpart which do not get any government subsidies. In addition to receiving subsides, conventional generation technologies have a lower tax burden.
7. Wind and solar power developers may have difficulty obtaining financing at rates as low as may be available for conventional energy facilities.
8. Good wind sites are often located in remote areas, far from the cities where electricity is needed most. Transmission lines must be built to bring the electricity from the wind farm to the city. This increases the cost of generating and providing electricity.
9. Wind resource development may not be the most profitable use of the land. Land suitable for wind mill installation must compete with alternative uses for land, which may be more highly valued than electricity generation. HEP and biogas in Tanzania Hydroelectric power (HEP) Hydroelectric power contributes about 57% of the total power generated in Tanzania. The electricity supply industry is dominated by Tanzania Electric Supply Company (TANESCO). The company operates hydropower generation stations which include Kidatu, Kihansi, Mtera, Pangani, Hale, Nyumba ya Mungu and Uwemba, totalling 561 MW of electricity.
TANESCO also generates thermal electricity using gas and diesel by plants located in various parts of the country. There are also independent power plants (IPPs) which produce thermal electricity from gas and diesel and then sell the generated power to TANESCO who feeds it to the national grid. Biogas Due to increasing demand for power and dwindling energy resources, there is need to develop alternative energy sources in Tanzania. One of such sources is biogas, which is used for heating, lighting, and cooking at homes, schools, hospitals, etc.
Biogas is produced by anaerobic digestion with anaerobic bacteria or fermentation of biodegradable materials such as manure, sewage, municipal waste, plant material, and crops. Biogas technology in Tanzania was introduced in 1975. But it was not until late 2000s when a study of the biogas sector and how to improve it was conducted. Then the sector saw improved progress in domestic biogas uptake. The government is collaborating with different development partners to improve on existing technologies and to construct new biogas plants for particularly rural communities. It is estimated that about 700 biogas plants have been constructed in Tanzania.
Most of these are in rural areas where raw materials such as livestock and poultry wastes and crop residues are easily and abundantly available.
Importance of HEP and biogas production in Tanzania
Hydroelectricity and biogas are very important power resources in Tanzania.
Outlined below are some of the importances of producing these resources:
1. Hydroelectricity and biogas industry employs people who carry out energy production activities. The sector, therefore, serves as the source of employment opportunities to some Tanzanians. This helps to improve their income and hence the standard of living.
2. The hydroelectricity generated in Tanzania is used to power other industries and sectors of economy. It, therefore, leads to industrial development as well as other economic sectors in the country.
3. Biogas generation in rural areas has greatly helped to improve the living standard of the rural people. Studies have revealed that now women and girls with access to biogas do not spend much time looking for firewood and hence they can instead direct their efforts towards participating in other economic activities to improve family income. It thus saves women and children from drudgery of collection and carrying of fireweed, exposure to smoke in the kitchen, and time spent for cooking and cleaning of utensils.
4. The use of biogas and hydroelectricity has greatly reduced the problem of cutting down trees for firewood. This has consequently helped to prevent deforestation, hence ensuring environmental conservation. Conversely, biogas combustion has no effect to environmental pollution since it produces negligibly very little pollutants into the atmosphere compared to wood, coal and petroleum. The use of municipal waste to generate biogas directly assists in cleaning of the environment and prevention of pollution that could result by dumping of these wastes on land or into water bodies.
5. Most of the biogas projects are undertaken by development partners from abroad. This has helped to improve the relationship between Tanzania and the partners’ mother countries.
6. The residue of the organic matter left back after biogas has been generated is used as enriched organic manure, which can supplement or even replace chemical fertilizers.
Problems facing HEP and biogas production in Tanzania
1. Unreliable climatic conditions: Hydroelectric power generation relies on rain-fed rivers and dams. There has recently been occurring long dry spells which lower the volumes of rivers and dams, thus curtailing hydroelectricity generation. This leads to power rationing and hence interruption in economic production.
2. Lack of adequate capital: Generation of HEP and biogas requires investment in installation of hydropower and biogas plants, respectively, all of which are hampered by availability of capital. Due to the country’s sluggish economy, investment in the power and energy sector has not been successfully implemented. There is lack of enough funds to finance the establishment of more biogas plants in rural areas. The country relies heavily on donors and foreign investors to finance the projects.
3. Siltation: The continuous accumulation of silt in the dams leads to reduction in water volume and hence low hydroelectricity generation. The problem also leads to increased operation costs because the silt has to be dredged periodically.
4. Lack of skilled personnel: The establishment and operation of hydroelectric and biogas plants require skilled personnel. There are very few locals with the required expertise and professional skills to operate the projects. This has hindered the construction of hydroelectric and biogas plants in the country. The production of energy and power from these two sources is thus minimal.
5. Reluctance by the people: People are still reluctant in adopting the biogas technology. Many people depend on use of wood as their major source of fuel. This has led to low investment in the industry and hence low production of the biogas.
Solutions to problems facing power production
1. The silt in dams should be removed frequently so as to prevent reduction in water volume and the consequent drop in production.
2. The government should invest in other forms of energy generation such as geothermal and coal power in order to reduce overdependence on hydroelectricity.
3. Establishment of training institutions to train manpower on energy production technology. This will help produce skilled manpower to manage the power sector.
4. Power generation must be liberalized in order to attract investors with sufficient capital to invest in the industry.
5. Conducting mass education to educate people to adopt the production and use of biogas. These can be done through seminars, trade shows and mass media, among other means. People benefiting from the use of biogas may be invited to convey the message to those individuals reluctant in adopting the technology.
Solutions to Problems Facing Power and Energy
Harnessing in Focal Countries Propose solutions to problems facing power and energy harnessing in focal countries Solutions to problems facing solar and wind power in the USA
1. Alternative sources of energy have been developed to supplement solar and wind power.
2. People must be taught about the benefit of wind and solar power in order to persuade them to switch from traditional to modern energy sources.
3. Government support as well as partnerships has enabled the setting up of power stations for wind and solar energy exploitation.
4. The government must provide subsidies to solar and wind research and development as it is doing to conventional technologies. Lessons from Countries for Better Harnessing of Power and Energy Resources in Tanzania As far as energy production is concerned, Tanzania has a lot to learn from the USA.
The following are some of the lessons that can be adopted and implemented:
1. In USA, the energy sector is liberalized, so many private companies are allowed to generate and sell energy and power. Tanzania should also copy USA’s example by allowing more private investors to participate in energy and power generation rather than allowing TANESCO to monopolize the energy production.
2. The USA has diversified its energy and power industry very well. The country generates power from different sources, ranging from nuclear to biogas plants. Tanzania can do the same by using natural gas, coal and uranium discovered in various parts of the country to produce the highly demanded power to boost her economy.
3. The government should form agencies to address the generation of solar and wind energy. There is great potential of wind and solar energy in Tanzania because of the presence of suitable conditions for harnessing these power recourses. There is plenty of wind and sunlight in the country to allow sustainable production of wind and solar energy, which can then be fed to the national grid to help solve the problem of energy in the country.
4. The government should support the development of various energy sources by providing funds to local companies as well as creating favourable investment conditions to multi-million energy production companies to invest in the energy generation sector.
5. The USA uses her own experts to develop the energy industry. Tanzania should also train her own people so that they can take active part in building energy generation projects rather than depending on skilled personnel from outside the country.