CHAPTER 07: SUSTAINABLE USE OF POWER AND ENERGY RESOURCES

Energy is the power required to carry out an activity. Power is the ability to do something (work). Therefore, Energy produces power that used to carry out an activity. Energy sources can be divided into the following two broad categories:

(a)Renewable sources

(b)Non-renewable sources

(a)Renewable Sources: Are those sources (resources) that cannot be finished or exhausted. For example, sun, wave, tides, geothermal steam and biogas or biomass. Renewable sources also are known as inexhaustible sources

(b) Non-Renewable Sources: These are sources that can be exhausted or finished. Nonrenewable sources, also known as exhaustible resources. Examples of Non Renewable resources are coal, petroleum, natural gas, fuel wood, nuclear energy and all radioactive mineral like uranium and plutonium.

Renewable Energy Sources and Non-Renewable Energy Sources:

1. Sun: The sun is the source of all the other sources of energy. This is because all the other sources of energy are in one way or another depends on the sun for their very existence. The Sun is the correction of hot gases. It produces solar energy, which is tapped in various ways by human and plants. Solar energy is used to produce chemical, heat and electric energy.

2. Waves and Tides: These are the strong movements of seawater. These movements are caused by the earth’s rotation, the gravitational pull of the moon as well as the movement of water particles. Waves and tides can be tapped to produce mechanical power, which is in turn to generate electricity.

3. Wind: Differences in atmospheric pressure cause movement of air; this moving air is referred to as wind. Wind energy can be converted into mechanical energy that may then, in turn, be used to produce electricity.

4. Biomass (Biogas): This refers to the existing plant and animal life in the environment. Biomass produces several forms of power and energy. It may be tapped to produce heat energy, mechanical energy as well as light energy.

5. Coal: Coal is formed due to compression of vegetative matter over very long periods of time. Due to its being covered by layers of mud, the vegetative material did not decompose completely, turning into coal due to the pressure and heat from the earth’s crust. It is black or brown in color. Coal it is used to produce heat energy. This heat energy may be used in different way including the generation of electricity.

6. Petroleum: Petroleum also referred to as crude oil. Oil is formed from fossilized remains of animals and plants. Used in producing mechanical energy, heat energy and light energy.

7. Natural Gas: Natural gas commonly occurs alongside petroleum. Like petroleum, it is formed due to the fossilized of plants and animals. Natural gas produces heat energy and light energy.

8. Uranium and Plutonium: These are two minerals, which are used to produce nuclear energy, that produce nuclear power. They occur naturally in the Earth’s crust.

Sources and Types of Energy

No.	Source Of Energy	Types Of Energy
01.	Sun	Solar, Mechanical, Electrical.
02.	Wave and tides	Electrical.
03.	Wind	Mechanical, Electrical.
04.	Biomass	Mechanical, (Biogas).
05.	Water	Mechanical, Electrical.
06.	Wood	Mechanical.
07.	Animals	Mechanical.
08.	Petroleum	Mechanical, Electrical.
09.	Natural gas	Mechanical.
10.	Coal	Mechanical, Electrical.
11.	Uranium	Nuclear or Atomic, Mechanical, Electrical

Tab. 7.1: Different sources of energy in relation to the types of energy

Methods Used in Extracting Energy and Power

The followings are some of the methods used in extraction of energy or power from different sources:

1. Coal: Coal is mined from the earth’s crust in various countries in the world. These include China, USA, and South Africa. The energy from coal is tapped by burning the coal. This produces heart-energy, which is used in various ways. It can be used for domestic heating, in industrial furnace, or used to boil water and produce steam, that can be used to power machinery and produce electricity.

2. Petroleum: It is refined before it is used. It is mined from the depths of the earth’s crusts and transported to refineries, where different products are obtained from it. The energy of petroleum and its products is also tapped mainly by burning. This burning produces heat energy, mechanical energy or light energy. Petroleum products may be used in industrial furnaces, to run machinery or produce light.

3. Natural Gas: Like petroleum, natural gas also requires to be refined before it can be used. This involves the separation of various gases. The energy is the natural gas that extracted through the burning of the gas. This produces heat energy, which is used for domestic heating, generating thermal electricity and industrial heating purposes.

4. Water: The energy in water may be tapped naturally or artificially. Naturally, waterfalls may be used to run turbines, which are used in the generation of electricity. Artificially, water may be channeled through pipes to high points from where it drops, turning turbines to generate electricity.

5. Biomass: This consists of plant and animal life. These are burned to give off heat energy as well as light energy. Plant residues, such as slashed grass or dry, dead leaves and processed agriculture waste such as Maize husks as well as lumbering residue such as saw dust; can also be burned to produce heat and light energy.

The heat energy may be used for domestic heating or used in industries in furnaces. Animal waste such as dried cow dung may be burned to produce heat energy. Combined with plant residue and light to decompose under controlled condition, it can be used in the production of biogas. This can be used for heating or lighting purposes.

6. Plutonium and Uranium: The energy in these two minerals is extracted through either of two processes. Nuclear fusion and nuclear fission involving the splitting of an atom stead to the release of large amount of heat that used to heat water and produce steam, which is in turn used to turn turbines that generate electricity.

7. Wind: The mechanical energy of wind is trapped in several ways. It may be used to turn windmills, which are used to generate electricity or to directly run machines such as grain grinding mills. It may be tapped by putting up sails to propel water vessel.

8. Geothermal Steam: The geothermal power in geothermal steam is extracted by directing it to run machines that produce electricity. Its heat energy can also be trapped by placing the materials to be heated over the hot steam.

Importance and Uses of Power and Energy Resources

The energy and power resources are important in the following ways:

1. Used in industry: Power and energy resources are used to produce energy and power to the industries. Power and energy are used to run machines, provide light, produce electricity and provide heat for processing goods.

2. Used for transportation: Motorcycles and vehicles, airplanes, trains and ships all need fuel to provide energy and power for them to work.

3. Important in Mining: Machines for mining and lighting inside and outside mines need power and energy.

4. Importance in Agriculture: Power and energy are used to run heavy farm machinery such as those used to plough or harvest crops. Most of these machines run on diesel, which is petroleum product.

5. Sources of Employment: Large numbers of people are employed in this sector both skilled and unskilled man power.

6. Sources of foreign exchange: The industry act as the source of foreign currency if energy and power resources are exported.

7. Sources of government revenue: Through taxes collected from this industry, the government tends to get revenue.

8. Improvement of transport and communication infrastructure: In the presence of power and energy resources in an area contribute to the improvement of transport and communication system because are needed so as to smooth the extraction of these resources.

9. Promotion of trade and other Industries: This human activity promote to the development of trade and other sectors because it integrate with other economic activities, like agriculture, transport system, and all social services which are in need to this human activity.

Problems or Challenges Facing Power and Energy Production

The following are the limitation facing power and energy production:

1. Change of climatic conditions: Occurrence of droughts and the general shortage in rainfall may lead to a fall in water level at waterfalls and dams at hydroelectric power stations. This leads to the reduction in power production.

2. Lack of varied energy resources in the country: Some countries have limited sources of energy, e.g. geothermal steam and uranium, hence countries depends on water and solar.

3. Poor technology: In most developing countries, there is lack technology for energy and power exploitation.

4. Lack of skilled labor: In some countries (developing countries) there also very few skilled people for setting up and operating equipment as well as conducting research in power and energy production methods, activities and technology.

5. High prices of some sources of energy: The price of petroleum on the world market, hence lead to the people to un-afford of buying it, since it is used also in the generation of thermal electricity.

6. Lack of capital: It is very expensive to set up energy and power generating facilities, hence some developing countries may not able to buy and meet these costs.

7. Environmental pollution: Energy and power production has been blamed for polluting the environment, hence this sector get high pressure to adopt methods that ensure little or no pollution of the environment.

8. Siltation: In generation of hydroelectricity may lead to the siltation in source of water. Siltation is the situation where silt (soil particle) accumulates in water reservoirs at hydroelectric power plants.

Ways to Address Problems Facing Power and Energy Production

The following are the suggested ways in order to solve the problems facing power and energy production:

(1) Removal of silt to ensure that, the dam capacity is reduced by the accumulation of silt.

(2) Country should diversify their energy production to reduce the effect of such factors as petroleum prices and climate.

(3) Developing countries should ensure that, they keep up with technological advancement.

(4) Research should be carried out often to improve energy and power production method as well as to come up with new production methods as well as less environmental pollution.

(5) Establishment of colleges, universities and other higher learning institutions to train professionals in the energy and power production field.

(6) Countries should collaborate to raise adequate capital to fund the setting up of power and energy production.

Case Study: Solar and Wind Power in the United State of America

The United States of America (USA) is the country that advanced in technology with a wealthy economy. It is a developed Country with great demand for power and energy for its industries and its large population.

Solar power accounts for a very small percentage of total energy production in the USA. It is mainly exploited in the sun areas of the country especially in California and Nevada. Wind power is more used compared to solar power in the USA. Wind power is used to generate 0.7% of the total electricity production in the country.

Wind power is used to run large farms, industries as well as generating electricity that is fed into the national grid. The wind power is tapped by the use of windmills. Texas is currently the largest wind power producer in the country followed by California. The wind power will generate about 1% of the total electricity produced in the country by the end of the year 2008.

The following are some of the Importance of Solar and Wind power in the USA:

(a) Source of employment. Solar and wind power sectors employ many Americans

(b) Industrial development. Industrial development depends on cheap and reliable availability of power and energy. Wind and solar energy continue to make this possible.

(c) Agricultural development. Wind power is used in large farms to provide electricity and heating. Also it is used in irrigating fields. This has promoted large-scale agriculture in the country.

(d) Conservation of non-renewable energy. Resources such as petroleum are ensuring that they do not run out too soon.

(e) Reduced environmental pollution. Solar and wind power do not pollute the environment as much as other resources such as petroleum.

(f) Improved standards of living. Solar and wind power have become an affordable sources of power for many Americans. Wind and solar power seemed to be cheap to many Americans; hence, this improved their standards of living.

The following are some of the problems facing solar and wind power in the USA:

(1)The cost of equipment used in tapping solar and wind power on large scale is quite high. This has led to the limited investment.

(2)The harnessing of solar and wind power is highly dependent on the prevailing weather conditions. In case there is little or no sunshine or low wind speed, then it is difficult to harness the power.

(3)People are still reluctant to change from the traditional energy sources such as hydropower.

Solutions to the problem facing solar and wind power in the U.S.A:

(1)Alternative source of the energy have been used to supplement solar and wind power.

(2)Associations and government departments have been formed to inform and educate people about the benefits of solar and wind power.

(3)Government supports as well as partnership have enabled the setting up of stations for wind and solar energy.

Case Study: Hydroelectric Power (H.E.P) and Biogas in Tanzania

1.      Hydroelectric Power

Hydroelectric power contributes the largest percentage of electricity generated in Tanzania. The Tanzania Electric supply company (TANESCO) is the main producer of HEP in Tanzania.

TANESCO produces electricity at several hydroelectric projects. The project include Nyumba ya Mungu and Hale on Pangani river, Lower Kihansi around the Kihanji and Mhalala water falls in the Udizungwa mountains in Southern highlands, Kidatu and Mtera on the Great Ruaha river and Stieglers Gorge on the Rufiji river. These projects have total installed capacity of generating more than 800 MW of electricity.

2.      Biogas

As a way to reduce dependence on petroleum and other nonrenewable energy resources such as fuel wood, the Small Industries Development Organization (SIDO) introduced the use of biogas in Tanzania. Most of this biogas is produced for domestic use. There are over 700 biogas plants in Tanzania today. Most of these are located in rural areas where raw materials such as cow dungs are easily available.

Importance of HEP and Biogas production in Tanzania:

(1) The use of Biogas has reduced environmental degradation. In areas where it is available, people no longer need to cut down trees to get fuel wood. Biogas also does not emit fumes when it is burned.

(2) Employment opportunity to Tanzanians. Many people are employed to carry out the various activities involved in the generation of biogas and hydroelectric power.

(3) Promotes development of other industries in the county. Electricity in hydroelectric power stations has played an important role in the growth and growth of other industries in the county.

(4) Improved standard of people’s living in the rural areas.  The availability of biogas and HEP in rural areas has greatly improved the standards of living of the people. Those who have access to biogas no long have to speed many hours looking for wood and are therefore able to concentrate on other important activities.

Problems facing HEP and Biogas Production in Tanzania:

(1)  Unreliable climate condition. Tanzania experience dry periods in summer season, hence this reduces hydroelectric power production leading to power rationing.

(2) Lack of capital. Tanzania is large country hence lack adequate capital to acquire and set up the Machinery and equipment needed to accommodate several electrical projects.

(3) Siltation. This reduces the volume of water in the dams. Thus, reducing capacity of electricity generation.

(4) Lack of skilled personnel. Setting up and operation of hydroelectricity power plants and biogas plants requires skilled personnel, but in Tanzania we lack such personnel hence this act as the sanction for HEP and biogas production in the country.

(5) Reluctance by the people. Some people are reluctant to adopt the Use of biogas. They consider it is dirty and lowly in status.

Solutions to the problems facing HEP and Biogas production in Tanzania:

(a)    Frequent dredging of reservoirs (removal of silt) to avoid siltation.

(b)   Development of other sources of power to reduce HEP which is highly affected by climate.

(c)    Establishment of training institutions to provide skilled personnel to work in power generation plants.

(d)   Liberalization of power generation might lead to greater availability of funds for development of HEP and biogas production.

(e)    Promotion and marketing by the government and other concerned organization will help to encourage people to adopt the production and Use biogas.

Lesson Tanzania Learns from the USA Energy and Power Production:

The following are some of the Lesson to be drawn by Tanzania from the USA energy and power production:

1.      The government should support the development of various energy sources as USA does.

2.      The government should form departments to encourage the development of alternative sources of energy such as solar power and wind power as USA do.

3.      Diversity – Tanzania should diversify her energy sources to reduce the negative impacts of reduced production from one source.

TRIAL QUESTIONS

Qn1. Define the following terms:

a)      Solar                             (c) Energy                   (e) Renewable source of power

b)      Power                           (d) Siltation                  (f) Nonrenewable source of power

Qn2. With vivid example, differentiate between non-renewable and renewable sources of      power.

Qn3. Describe the extraction of energy or power from any two sources of energy.

Qn4. (a) State five problems that faces HEP production in Tanzania

  (b) Suggest solutions to the problem you have stated in above.

Qn5. Explain five reasons why energy or power resources are important