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Energy

 

 

Objectives

By the end of this topic, you should be able to:

define the term 'energy'.
identify and discuss the various sources and types of energy.
 

Objectives

By the end of this topic, you should be able to:

a) define the term energy.
b) identify and discuss the various sources and types of energy.
 

ENERGY

Welcome to the topic Energy. Energy is defined as the power required to carry out an activity. Energy is present in natural forces such as wind, water and sunshine. It is necessary for the production of goods and services.

 

     Management and conservation of energy.
 

Management of energy refers to the effective use and planning of the available energy resources. On the other hand, conservation of energy refers to the efficient usage of energy resources to minimize wastage and depletion.
Some of the measures taken in the management of energy include:

  •  Control of the importation of vehicles with high engine capacity to lower oil imports.
  • Encouraging the use of public service vehicles instead of private vehicles, to lower fuel consumption.

INSERT:  Photographs of motorists, mini buses, buses carrying people.

  • Creating public awareness on energy saving measures to reduce wastage through public forums, media advertisements and programmes and general education in schools and colleges.
  • Planning and construction of wider roads to ease traffic congestion as much fuel is lost in the traffic jams.

INSERT:  Photographs of the Thika super highway.
      Photographs VW Passat vehicles used by government officials.
     Photographs of the higher engine capacity e.g. Mercedes Benz and other fuel     guzzlers'
The Kenya government has also taken several measures to conserve energy, including the following:

  • Encouraging people to use alternative sources of energy, e.g. sun, wind and biomass.
  • Encouraging afforestation, reafforestation and agroforestry programmes to ensure sufficient supply of wood fuel in the market.

INSERT:  A video clip of reaforestation of the Mau forest.
Photographs of farms where crops and trees are growing together e.g.       Gravellia robusta trees in a farm.

  • Encouraging people to use energy saving stoves (jikos) for domestic purposes and for institutions.

INSERT: Photographs of energy saving stoves and fireplaces especially larger ones used in institutions.

  • Emphasis is being laid on management of existing forests by banning logging, training foresters, evicting squatters and fencing forests among others.

INSERT:  Photographs of evictees from Mau forest, Mt. Kenya  forest and any other, as    example of conservation measure.
                  A video clip of such activities as baraza's urging people to conserve forests.

Sources and types of energy.

Sources of energy are classified into two categories namely:

  • Renewable sources, and
  • Non-renewable sources.


 

Renewable sources of energy

Renewable sources of energy are those that can be regenerated and used over a long period of time. These include the sun, wind, water, geothermal steam, biomass, wood, animals and tides and waves.

The sun

The type of energy from the sun is called solar energy. Solar energy can be converted into heat, chemical and electrical energies. For example, solar panels are used to tap solar energy and convert it to electrical energy. This is used for lighting and heating. Solar energy is also used in electrical appliances such as calculators and mobile phones. This type of energy is very abundant in tropical regions of the world where it has been used traditionally directly for drying crops such as maize, rice, coffee and sisal.

 

Advantages of using solar energy

Solar energy has a number of advantages and disadvantages. The following are some of the advantages:

  • It is inexhaustible and available in almost all parts of the world.
  • It is cheap, absolutely free and easy to tap.
  • Requires relatively little capital to install and maintenance cost is low.
  • It is a clean source of energy and environmentally friendly.
  • Solar energy can be stored in batteries for later use.
  • It has a wide range of uses from simple drying of things and lighting to powering satellites.

Disadvantages of using solar energy

There are however, some shortcomings concerning the use of solar energy. The following are some of them:

  • Solar panels have low energy output. This makes its use to be limited to lighting and household appliances.
  • The batteries used for storage are cumbersome and require regular replacement.
  • Solar panels are expensive to manufacture and are fragile.

The wind

Energy from wind is called wind energy. Wind mills are used to convert wind energy into mechanical energy that is used in various ways. These include pumping water, grinding cereals and generating electricity.

For centuries, wind energy has been exploited for propelling ocean going vessels such as dhows and ships. Potential areas with wind energy are mainly those with open landscapes. These include the arid and semi arid parts of northern Kenya and the coastal areas.

Advantages of using wind energy

There are a number of advantages attributed to use of wind energy. The following are some of them:

  • It is inexhaustible because the source which is the wind is always blowing.
  • It is cheap because it is naturally occuring.
  • It is a clean type of energy because it does not pollute the environment.
  • It can be produced on small scale by individual consumers.
  • On the wind farm, land can also be used for other purposes such as growing short crops.

Disadvantages of using wind energy

  • A wind mill produces relatively small amount of energy. Many windmills are needed to produce a substantial amount of energy.
  • Since the wind may change direction anytime, wind energy may be unreliable. For example, sailors may have to delay sailing until winds are blowing in the right direction.
  • Windmills occupy large tracts of open land. Their presence diminishes the aesthetic value of that particular land.

Water

Energy obtained from water is referred to as water power or hydro-power. The energy is produced when water is in motion. Water flowing at high speed has a lot of kinetic energy which can do work. For example, the force of water can be used to turn the grinding mills for cereals. The energy is also used to turn turbines which generate hydro-electricity.

Advantages of water power

Water power has the following advantages:

  • It is a clean type of energy that does not pollute the environment.
  • It is inexhaustible so long as the source is properly managed.
  • It can be generated in one place and distributed over long distances.
  • It is relatively easy to use as one only requires to operate simple switches.
  • It can be used for many purposes.
  • It provides high energy output.
  • It can be used in many parts of the world and especially if the regions have rivers.

Disadvantages of using water power

  • Water power generation is subject to fluctuation in volume of water in the river. This leads to lower production of power.
  • Construction of dams to generate electricity interferes with aquatic life. For example migration of certain species of fish is hampered.
  • The reservoirs created by construction of power dams cause re-settlement of people leading to disruption of their social lives.
  • The high cost of construction, installation and distribution hinders expansion of power production.
  • Hydro-electricity cannot be stored for future use.

 

Geothermal steam

This is water vapour that issues naturally from the ground. It is a result of underground super-heated water being forced out onto the surface by high pressure underground. It is therefore common in volcanic areas although it can also be found in non active volcanic areas.The steam is harnessed to generate geothermal electricity.This is done at Ol Karia, near Naivasha in Kenya. It is also produced in New Zealand, Japan, Italy and the USA.

Advantages of geothermal electricity

 

  • It is a clean type of energy that is also environmentally friendly.
  • It is inexhaustible since steam is continuously produced from the ground.
  • It helps reduce over-dependence on fossil fuels as a source of energy.
  • It also supplements hydro-electricity production which fluctuates seasonally.

Disadvantages of geothermal electricity

  • The gases emitted from the generating plant for example, sulphur dioxide, ammonia, methane and hydrogen sulphide cause health problems.
  • Exploration and generation are expensive as they require advanced technology.

Biomass

Biomass is plant and animal matter that can be converted into usable energy through biological or thermo-chemical processes. In the process, gas is given off and it can be burnt to produce heat. Animal waste such as cow dung and human waste are used to produce gas. Solid biomass especially vegetable matter can be converted into liquid fuel such as ethanol, methanol and liquid hydrocarbons. The gas that is produced is called biogas and is used for cooking, lighting and powering generators.


 

Advantages of using biogas

  • It is an inexhaustible type of energy since the biomass is continually being produced.
  • It is a clean type of energy.
  • It is cheap as it utilizes waste products most of which are readily available in homes.
  • It reduces environmental pollution by burning methane gas which is a pollutant.

Disadvantages of using biogas

  • Its use is limited to the vicinity of the digesters since it cannot be transported over long distances.
  • Energy output from the gas is low and this limits its use to domestic areas only.
  • When some of the gas produced leaks into the atmosphere, it causes environmental pollution. The biomass also gives a foul smell.

Wood

Wood has, from time immemorial, been a source of energy in homes, locomotives and industries. It is a source that occurs in form of firewood, charcoal and sawdust.

These materials are burnt to produce heat used for cooking, heating and lighting. Wood fuel is widely used to supply energy for domestic purposes with only a small percentage being used in processing industries to heat boilers and furnaces.

Advantages of using wood fuel

  • Wood is readily available in many parts of the world.
  • It is cheap as wood is used in its raw form.
  • It is easy to use as it only requires to be lit to produce heat.

Disadvantages of using wood fuel

  • The high demand for wood fuel leads to indiscriminate cutting of trees and subsequent environmental problems. These include soil erosion, disruption of the ecosystem and desertification.
  • The gases and smoke emitted due to burning of wood, charcoal and sawdust pollute the environment.
  • Handling of wood and charcoal is a dirty affair on the persons involved. Disposal of charcoal dust and ashes makes the environment dirty.
  • Wood fuel has low energy output which limits its use.

Animals

Animals are used in various parts of the world to perform various tasks. For example, oxen are used for ploughing,grinding cereals and pulling carts. Donkeys, camels, horses, llamas, elephants and dogs are also used in various forms of transportation.


INSERT: Photographs of the various drought animals doing work as listed above. Of particular importance are dogs pulling sledges, llamas pulling carts. (internet or videos).
INSERT:  Video clips of oxen ploughing in a farm, donkeys pulling carts laden with baggage, and others carrying loads directly, Camels carrying luggage on their backs, elephants in India/south-east Asia. Photographs of llamas could be taken at Egerton University.
 

Advantages of using animals

  • Animals are readily available all over the world.
  • They incur low maintenance costs as they require mainly food and water.
  • Animals are very flexible as they can be used for a variety of activities.
  • They have adaptive characteristics enabling them to survive extreme weather conditions.

Disadvantages of using animals

  • Animals easily get tired which reduces their ability to work.
  • They are prone to attacks by pests and diseases that may lead to their death or lower their productivity.
  • Animal energy is restricted to the performance of simple tasks and on small scale.

Tides

Ocean tides are a potential source of power which, when harnessed, can produce tidal power. A tide moves a huge amount of water twice each day. If this is harnessed, it could provide a great deal of energy. A tidal barrage, which is actually like that of the hydro-electric scheme but much larger, is built across a river estuary. It has gates which are tunnels through which tidal water flows. The ebb and flow of the tides can be used to turn a turbine.It can also be used to push air through a pipe, which in turn turns a turbine.The largest tidal power station in the world and the only one in Europe is on the La Rance River estuary in northern France, near St. Malo. It was built inn 1966 and produces 240 megawatts of electricity.


 

Advantages of tidal power

  • It is cheap in that once construction of the power station is done, production depends on free water and no fuel is used.
  • It is friendly to the environment as it does not produce greenhouse gases and other wastes.
  • Electric power production is reliable as tides are very predictable and must occur daily.

Disadvantages of tidal power

  • It is expensive to construct a barrage across an estuary as it affects a very wide area.
  • Power can be produced for only ten hours a day when the tide is moving in or out.
  • Sites for construction of barrages are limited to estuaries which are not widespread.
  • Barrages cause changes in the environment both on the upstream and downstream sides of the estuary. For example, mudflats may not be uncovered for birds to feed while fish can't easily migrate up the estuary.

Waves

Sea waves are a powerful source of energy. It is however, not easy to harness this energy and convert it into electricity in large amounts. This explains why wave power stations are rare.A wave power station is built near the shore and has a large chamber. As waves arrive, they cause the water in the chamber to rise and fall. As this goes on, air within the chamber is forced in and out of the hole in the top part of the chamber. As the air is forced in and out of the hole, it turns a turbine that is placed in the hole. The turbine then turns a generator to produce electricity.There is a wave power station called Limpet on the Scottish island of Islay.
Many more ideas, from various companies, are coming up to develop alternative technology of harnessing waves.
 

Advantages of wave power

 

  • Wave energy is cheap to produce since no fuel is required to generate it.
  • A lot of energy can be produced from waves.
  • It ensures a clean environment as there is no waste produced.

Disadvantages of wave power

  • Harvesting is limited to sites where waves are consistently strong.
  • Very rough weather could cause interference with the equipment used.
  • Its production is dictated by presence of waves such that during calm weather, no electricity is produced.

Non-renewable sources of energy

Non-renewable sources of energy are exhaustible because they lack the natural capacity of recycling themselves once they are used up. Examples of these include coal, natural gas and uranium.

Petroleum

The term petroleum refers to the gaseous and liquid hydrocarbons from animal and plant matter that were laid down, compressed and turned into these forms within the sedimentary rocks.
When petroleum is refined, a variety of products are obtained. These include petrol (gasoline), diesel, aviation fuel, bitumen, liquefied gas, asphalts, kerosene and lubricants such as grease and lubricating oil. These products are used for various purposes. Industrial diesel is used in industries in boilers and furnaces, to generate thermal electricity, fuel for vehicles, aircraft and machinery, ships and locomotive engines and in households for cooking, heating and lighting.


 

Advantages of petroleum as a source of power

  • It can be transported over long distances using tankers and pipelines.
  • It can be used to generate other forms of energy, e.g. thermal electricity.
  • It has a high energy output.

Disadvantages of petroleum as a source of power

  • Crude oil is bulky and therefore difficult and expensive to transport.
  • It is an exhaustible source of energy.
  • The cost of petroleum products is generally high and unaffordable to many.
  • It is one of the major environmental pollutants that contribute to global warming.
  • Exploration of oil is expensive therefore unaffordable to many developing countries.

Coal

Coal is a black or brown rock, mainly made up of carbon that was formed millions of years ago from compression of plant matter.There are four types of coal according to composition, characteristics and stages in development.

Traditionally, coal has been used for cooking and heating in houses. Later, it played a very significant role as a major source of energy in the European industrial revolution in the 18th century. It was used to run machines by heating boilers which produce steam. This was common in steam ships and steam locomotives.

Use of coal as a source of power has declined in recent years with the discovery of petroleum, hydroelectricity and geothermal power. Other factors contributing to its declined usage are;

  • Exhaustion of coal mines
  • High cost of extraction, and
  • Absence of easily accessible resources.

Advantages of coal as a source of energy

  • Coal has a high capacity of generating thermal electricity.
  • Coal is the most suitable form of energy in the smelting of iron and production of steel.

 

Disadvantages of coal as a source of energy

  • It gets exhausted and so cannot be renewed.
  • It is bulky, hence difficult and expensive to transport.
  • Some of the types of coal have a low energy output.
  • Coal produces a lot of soot. It therefore leaves a lot of dirt and soot on those handling it as well as in areas of storage and use.
  • Mining of coal has led to environmental degradation.

 

Natural gas

Natural gas is a type of gas that forms underground and forms on the upper layers of crude oil but may also occur on its own. It is composed of a mixture of hydrocarbons and non-hydrocarbon gases in small quantities. It is used for domestic purposes for cooking, lighting and heating and in industries especially for heating. It is also used for generation of thermal electricity e.g. Eg. Tanzania.

Advantages of natural gas

  • It is a clean source of energy
  • It is easy and safe to transport by pipelines.
  • It is easy to use as one only needs a button or tap to turn it on and off.

 

Disadvantages of natural gas

  • Gas is prone to accidents as it is highly flammable.
  • It is an exhaustible source of energy that cannot be replenished.
  • It is expensive and therefore unaffordable to a majority of people.

Uranium

This is a naturally occurring radioactive mineral. It is used to generate nuclear energy in a nuclear reactor, through a process known as fission. Inside the reactor, heat is released and it is used to produce steam which in turn is used to generate electricity.

Advantages of Uranium

The use of uranium as a source of energy has some advantages. They include the following:

  • The world's uranium deposits will provide a source of energy for a long time to come as most of the reserves are still unexploited.
  • It produces a high amount of energy.

Disadvantages of Uranium

There are some disadvantages associated with uranium and nuclear energy as outlined below.

  • Installation of nuclear reactors is very expensive.
  • The waste from the nuclear reactors is highly radioactive and difficult to dispose.
  • Uranium is exhaustible.
  • When accidents occur, they cause immense damage and loss of life.

Water

Energy obtained from water is referred to as water power or hydro-power. The energy is produced when water is in motion. Water flowing at high speed has a lot of kinetic energy which can do work. For example, the force of water can be used to turn the grinding mills for cereals. The energy is also used to turn turbines which generate hydro-electricity.
 

Advantages of water power

Water power has the following advantages:

  • It is a clean type of energy that does not pollute the environment.
  • It is inexhaustible so long as the source is properly managed.
  • It can be generated in one place and distributed over long distances.
  • It is relatively easy to use as one only requires to operate simple switches.
  • It can be used for many purposes.
  • It provides high energy output.
  • It can be used in many parts of the world and especially if the regions have rivers.

INSERT: photographs of power lines, electricity sub-station (Roysambu and Ruiru), Street lighting at night, electric cooker, refrigerator, a fan, television. Add a video clip of an industrial production unit where there are conveyor belts moving objects e.g. Coca Cola Bottling Plant.
 

Disadvantages of using water power

 

  • Water power generation is subject to fluctuation in volume of water in the river. This leads to lower production of power.
  • Construction of dams to generate electricity interferes with aquatic life. For example migration of certain species of fish is hampered.
  • The reservoirs created by construction of power dams cause re-settlement of people leading to disruption of their social lives.
  • The high cost of construction, installation and distribution hinders expansion of power production.
  • Hydro-electricity cannot be stored for future use.

Obtain photos showing low levels of water in reservoirs (dams) from KENGEN or KBC.
 

Geothermal steam

This is water vapour that issues naturally from the ground. It is a result of underground super-heated water being forced out onto the surface by high pressure underground. It is therefore common in volcanic areas although it can also be found in non-volcanic areas.
The steam is harnessed to generate geothermal electricity. This is done at Ol Karia, near Naivasha in Kenya. It is also produced in New Zealand, Japan, Italy and the USA.
 

Advantages of geothermal electricity

  • It is a clean type of energy that is also environmental friendly.
  • It is inexhaustible since steam is continuously produced from the ground.
  • It helps reduce over-dependence on fossil fuels as a source of energy.
  • It also supplements hydro-electricity production which fluctuates seasonally.

Disadvantages of geothermal electricity

 

  • The gases emitted from the generating plant for example sulphur dioxide, ammonia, methane and hydrogen sulphide can cause health problems.
  • Exploration and generation are expensive as they require high technology.

Biomass
Biomass is plant and animal matter that can be converted into usable energy through biological or thermo-chemical processes. In the process, gas is given off and it can be burnt to produce heat. Animal waste such as cow dung and human waste are used to produce gas. Solid biomass especially vegetable matter can be converted into liquid fuel such as ethanol, methanol and liquid hydrocarbons. The gas that is produced is called biogas and is used for cooking, lighting and powering generators.
                                                                                                      

Advantages of using biogas

 

  • It is an inexhaustible type of energy since the biomass is continually being produced.
  • It is a clean type of energy.
  • It is cheap as it utilizes waste products most of which are readily available in homes.
  • It reduces environmental pollution by burning methane gas which is a pollutant.

Disadvantages of using biogas

 

  • Its use is limited to the vicinity of the digesters since it cannot be transported over long distances.
  • Energy output from the gas is low and this limits its use to domestic areas only.
  • When some of the gas produced leaks into the atmosphere, it causes environmental pollution. The biomass also gives a foul smell which spoils the air.

Wood

Wood has, from time immemorial, been a source of energy in homes, locomotives and industries. It is a source that occurs in form of firewood, charcoal and sawdust. These materials are burnt to produce heat used for cooking, heating and lighting. Wood fuel is widely used to supply energy for domestic purposes with only a small percentage being used in processing industries to heat boilers and furnaces.

Advantages of using wood fuel

 

  • Wood is readily available in many parts of the world.
  • It is cheap as wood is used in its raw form.
  • It is easy to use as it only requires to be lit to produce heat.

Disadvantages of using wood fuel

 

  • >The high demand for wood fuel leads to indiscriminate cutting of trees and subsequent environmental problems. These include soil erosion, disruption of the ecosystem and desertification.
  • >The gases and smoke emitted due to burning of wood, charcoal and sawdust pollute the environment.
  • >Handling of wood and charcoal is a dirty affair on the persons involved. Disposal of charcoal dust and ashes makes the environment dirty.
  • >Wood fuel has low energy output which limits its use.

Animals

Animals are used in various parts of the world to perform various tasks. For example, oxen are used for ploughing, grinding cereals and pulling carts. Donkeys, camels, horses, llamas, elephants and dogs are also used in various forms of transportation.
 

Advantages of using animals

 

  • Animals are readily available all over the world.
  • They incur low maintenance costs as they require mainly food and water.
  • Animals are very flexible as they can be used for a variety of activities.
  • They have adaptive characteristics enabling them to survive extreme weather conditions.

Disadvantages of using animals

 

  • Animals easily get tired which reduces their ability to work.
  • They are prone to attacks by pests and diseases that may lead to their death or lower their productivity.
  • Animal energy is restricted to the performance of simple tasks and on small scale.

Tides

Sea tides are a potential source of power which, when harnessed, can produce tidal power. A tide moves a huge amount of water twice each day. If this is harnessed, it could provide a great deal of energy. A tidal barrage,;which is actually like that of the hydro-electric scheme but much larger, is built across a river estuary. It has gates which are tunnels through which tidal water flows. The ebb and flow of the tides can be used to turn a turbine. It can also be used to push air through a pipe, which in turn turns a turbine.
The largest tidal power station inn the world and the only one in Europe is on the La Rance River estuary in northern France, near St. Malo. It was built inn 1966 and produces 240 megawatts of electricity.

Advantages of tidal power>
  • It is cheap in that once construction of the power station is done, production depends on free water and no fuel is used.
  • It is friendly to the environment as it does not produce greenhouse gases and other waste.
  • Electric power production is reliable as tides are very predictable and must occur daily.

Disadvantages of tidal power

  • It is expensive to construct a barrage across an estuary as it affects a very wide area.
  • Power can be produced for only ten hours a day when the tide is moving in or out.
  • Sites for construction of barrages are limited to estuaries which are not widespread.
  • Barrages cause changes in the environment both on the upstream and downstream sides of the estuary. For example, mudflats may not be uncovered for birds to feed while fish can not easily migrate up the estuary.

Waves

Sea waves are a powerful source of energy. It is however, not easy to harness this energy and convert it into electricity in large amounts. This explains why wave power stations are rare.
A wave power station is built near the shore and has a large chamber. As waves arrive, they cause the water in the chamber to rise and fall. As this goes on, air within the chamber is forced in and out of the hole in the top part of the chamber. As the air is forced in and out of the hole, it turns a turbine that is placed in the hole. The turbine then turns a generator to produce electricity.
There is a wave power station called Limpet on the Scottish island of Islay.
Many more ideas, from various companies, are coming up to develop alternative technology of harnessing waves.

Advantages of wave power

  • Wave energy is cheap to produce since no fuel is required to generate it.
  • A lot of energy can be produced from waves.
  • It ensures a clean environment as there is no waste produced.

Disadvantages of wave power

  • Energy production fluctuates according to presence of effective waves.
  • Harvesting is limited to sites where waves are consistently strong.
  • Very rough weather could cause interference with the equipment used.
  • Its production is dictated by presence of waves such that during calm weather, no electricity is produced.

Electric power projects in Kenya

There are three major electric power projects in Kenya namely, hydro-electric power, geothermal power and thermo-electric power.

Hydro-Electric power projects in Kenya

Other hydro-electric power projects already completed include Turkwel Gorge, generating 106 MW, Sondu Miriu, generating 60 MW, Sagana, Wanjii and Gogo Falls dam. There are other proposed dams along River Tana which include Mutonga to produce 60 MW, Adamson (80 MW), Moraq (40 MW), Karura (50 MW) and Usweni (70 MW).

Hydo-Electric power projects in Uganda

The Owen Falls Dam was constructed over the Owen falls in 1954 to form East Africa's largest storage dam. A power station called the Nalubaale Power Station was also built. (Nalubaale is a Luganda name for Lake Victoria).
The rating of the Nalubaale power station is 180 megawatts (MW). Originally it was designed for ten turbines rated at 15MW each (giving a total of 150 MW). The station was refurbished in the 1980s to repair the accumulated wear from a decade of civil disorder. During the repairs, the output power of the generators was increased.


 

In 1993 work started on the Owen Falls Extension project, a second powerhouse located about 1km from the 1954 powerhouse. A new power canal was cut to bring water from Lake Victoria to the new powerhouse. Major construction was completed in 1999 with first power from the project from two units in 2000. The extension has space for five hydroelectric turbine generaters with three installed as of 2003. Each unit at the extension has a capacity of 40 megawatts. During official opening ceremonies in 2003, the extension was named the Kiyira is also a Luganda name for River Nile.It produces 162 MW enough to sustain the initial energy requirements for Uganda with some for export to Kenya.

 

Uganda intends to expand her power generating capacity by allowing private companies to set up more stations. At Bujagali Falls 8km downstream of the Nalubaale Power station, a new power station with projected capacity of 200-290 MW is under construction. It is expected to be completed in 2012 with partial power generation expected to start in 2011.
 

There are other smaller stations currently generating about 50 MW in total. They include Bugoye, Buseruka, Ishasha, Mpanga, Nyagak and Kasiizi. Another five bigger stations are in plan and are expected to be completed in due course.

 

Another five stations are either projected or are under construction. These are expected to boost power production in Uganda. Uganda has an additional seven thermo-power stations most of them using fuel oil to produce electricity. Two of them use biodiesel, one uses bagasse and the rest use fuel oil and diesel.
Power generation in Uganda is managed by The Uganda Electricity Board which was established before independence. The distribution of power is under the Uganda Electricity Transmission Company Ltd.


 

Geothermal power projects in Kenya

As earlier discussed, geothermal power refers to electric power generated from steam that issues naturally from underground. This steam is produced by superheated water from inside the earth. Water is superheated when it gets in contact with very hot rocks inside the earth. These rocks are hot due to volcanic activities inside the earth. These rocks occur in parts of the rift valley. Such areas can be identified by the presence o f hot springs, steam jets or geysers.

 

The exploration of geothermal power in Kenya started as early as 1956. The first station at Phase I was set up at Ol Karia in 1981, producing 45 MW. Phase II project became operational in 2004, generating 70MW. There is a private company, Orpower, generating 12 MW. The Kenya Electricity Generating Company (KENGEN) is currently working on Ol Karia Phase III.

The other potential areas for production of Geothermal power are:

  • Eburru, to the west of Lake naivasha.
  • Menengai Crater region.
  • Areas around Lakes Bogoria, Baringo, Turkana and Magadi.
  • The area between Mount Longonot and Suswa.
  • Homa Hills area.

Summary

Electric power projects in Kenya and Uganda

OBJECTIVE:

By the end of this session, you should be able to:

  • discuss the development of electric power projects in Kenya and Uganda.
  • identify and explain the factors that favour development of hydro-electric power.
  • identify and explain the problems facing hydro-electric power projects.
  • identify and locate other hydro-electric power projects in Africa.
  • to discuss geothermo power production in Kenya.
  • explain the significance of energy.
  • explain the impact of the energy crisis in the world.
  • Discuss ways and means of managing and conserving energy
  • Demonstrate the ability to manage and conserve energy.

Factors favouring development of hydro-electric power.

The factors favouring development of hydro-electric power can be divided into two categories namely, physical factors and human factors.

Physical factors

Physical factors include the following:

  • Presence of a large and constant volume of water. This is necessary in order to turn the turbines  that are used in generation of hydro-electric power.

  • A good head of water /falling water / waterfalls. This is necessary to provide the force required to rotate the turbines.

Presence of a deep and narrow valley or gorge.This minimizes the cost of constructing the dam. It also provides ample space for a large volume of water to accumulate.

Presence of a hard basement rock. This helps in providing a strong foundation for the dam.

Presence of impermeable rocks especially on the river bed. This reduces the rate of seepage of water thus maintaining the water volume in the reservoir.

Human factors

The human factors include:

  • Sparse population in the area. This reduces the cost of relocation of the people that are displaced by creation of the reservoir.
  • Availability of market.Hydro-electric power is non-storable and as such, the presence of industries provides ready market for the power generated.
  • Adequate capital.This is meant to cover the heavy costs of installation, maintenance and transmission of the power to the consumers.

 

Problems facing hydro-electric power projects.

Generation of hydro-electric power encounters some challenges ranging from establishment of the plant, generation to maintenance. These challenges include:

 Fluctuation of water levels

Inadequate capital

 Siltation of reservoirs

Displacement of people

Habitat for pests and dangerous animals

Fluctuation of water levels

During the dry season, the volume of water in the rivers may be low and this leads to a reduction in the capacity of the power station to generate sufficient electric power. Some stations may be shut down altogether. This was the case at Masinga Dam during the drought of 2009.

Inadequate capital

The power projects require huge capital outlay for the development of hydro-electric power. This is generally unavailable among the developing countries and has to be borrowed.

Siltation of reservoirs

This reduces the capacity of the reservoirs to hold the projected amounts of water. This leads to reduction in capacity of the reservoirs. The solution to this problem is regular dredging which is expensive.

Displacement of people.

Construction of dams and creation of reservoirs takes up large tracts of land that were formerly occupied by settlements. People of the area are displaced leading to social disintegration as people are separated within their communities.

This school was translocated to give room for the construction of the Sondu-Miriu Hydro-electric Power project.

 Habitat for pests and dangerous animals.

The reservoirs harbor pests such as mosquitoes and animals such as hippos and crocodiles which are a danger to livestock and people living within the vicinity of these reservoirs.

Location of other hydro-electric power projects in Africa.

The map of Africa provided shows Africa's major hydro-electric power projects. Find out their names and countries where each one is located.

Significance of energy.

The various forms of energy have a lot of significance to human activities. These include:

Domestic use

Industries

Transport

Agriculture

Water

supply

Medical purposes

Domestic use. Wood and charcoal are widely used in homes for cooking, lighting and heating. The various forms of electric power are used in homes for the same purposes. However, this form of energy is used more by the middle and high class societies. In addition to the uses mentioned already, electricity is also used for vacuum cleaning, running electronic components such as television, radio, computers, refrigerators, ironing and air conditioning.

INSERT:  Photographs / video clip showing the various uses of energy in homes.

Industries.

Very many industries use thermal or electric power to run the machines. Energy is therefore very important in the manufacturing and processing industries. Even coal and wood are used in some industries such as iron smelting and tea factories respectively.

Transport

A lot of energy is used in the transport sector. Petroleum products are widely used to run motor vehicles, trains, aircraft and ships. In industrialized countries, there are trains that use electricity. Cars that use solar power are being developed. However, continued use of petroleum products especially those that give off smoke is harmful to the environment.

Agriculture.

Petroleum fuel is widely used in farm machinery thus making mechanization of farming possible. It is used in tractors and combined harvesters. Electricity is used for lighting, heating and milking of cows in the dairy industry.

Water supply

Wind energy is used to run wind mills which in turn pump water from underground to the surface. Diesel and petrol (gasoline) as well as electricity are also used to drive water pumps.

Medical purposes.

In hospitals and other medical facilities, electricity is used to run or operate machines such as X-rays, dialysis machines, and refrigerators for preserving specimens.

The energy crisis

The term energy crisis refers to a situation whereby the demand for oil is higher than the amount that is being supplied, leading to high oil prices.

Causes of Energy Crisis

What are the causes of energy crisis?

The following circumstances have, over time, triggered energy crises in the world.

  • Escalation of world oil prices triggered by a sharp rise in demand.
  • Uncertainties in the world oil market caused by wars and political instability.
  • Control of huge world oil reserves by a few countries, who sometimes hoard the product causing artificial shortage.
  • Rapid depletion of reserves thus lowering the supply.
  • Unequal distribution pattern of crude oil in the world.

Photographs of long queues of motor vehicles at petrol stations waiting to refuel. People queuing at petrol station waiting to buy kerosene.

What is the impact of the energy crisis in the world?

An increase in oil prices leads to negative effects on the economies of oil-importing countries. The effects include:

Increase in transportation costs

Increase in prices of commodities

Reduction in government revenue

High cost of agricultural inputs

Closing of industries

Destruction of forests

Increase in transportation costs.

This causes inflation tendencies which lowers the people's purchasing power thus lowering their standards of living

Increase in prices of commodities

This is caused by increased cost of production and transportation of goods as a result of high cost of oil. This too lowers the living standards of the people.

Reduction in government revenue.

This is caused by the negative balance of trade as much of the country's foreign exchange is used for importation of oil. This slows the economic development.

High cost of agricultural inputs.

A rise in cost of oil affects the agricultural sector when inputs including diesel used in tractors become costly. This leads to lower agricultural output when farmers cannot afford the cost of production. In turn there is food shortage which leads to famine.

Closing of industries.

Industries that use petroleum by products as raw materials end up closing when these raw materials are no longer available. The workers in these industries are also laid off leading to unemployment.

Destruction of forests.

When oil and oil products become expensive, people turn to use of charcoal and wood fuel as alternative source of energy. This may lead to desertification.

The energy crisis can however, impact positively in the following ways:

The crisis motivates scientists to research into finding alternative sources of energy. In turn, countries invest in alternative sources of energy as a substitute to petroleum. For example, Kenya is investing in H.E.P., solar power, wind and geothermal power.

Energy crisis motivates the producing countries to export more to capitalize on the high market prices.

Management and conservation of energy.

Management of energy refers to the effective use and planning of the available energy resources. On the other hand, conservation of energy refers to the efficient usage of energy resources to minimize wastage and depletion.

Some of the measures taken in the management of energy include:

  • Control of the importation of vehicles with high engine capacity to lower oil imports.
  • Encouraging the use of public service vehicles instead of private vehicles, to lower fuel consumption.
  • Creating public awareness on energy saving measures to reduce wastage through public forums, media advertisements and programmes and general education in schools and colleges.
  • Planning and construction of wider roads to ease traffic congestion as much fuel is lost in the traffic jams.
  • Encouraging people to use alternative sources of energy, e.g. sun, wind and biomass.
  • Encouraging afforestation, reafforestation and agroforestry programmes to ensure sufficient supply of wood fuel in the market.
  • Encouraging people to use energy saving stoves (jikos) for domestic purposes and for institutions.
  • Emphasis is being laid on management of existing forests by banning logging, training foresters, evicting squatters and fencing forests among others.

    The energy crisis

    The term 'energy crisis' refers to a situation whereby the demand for oil is higher than the amount that is being supplied, leading to high oil prices.
    What are the causes of energy crisis?
    The following circumstances have, over time, triggered energy crises in the world.

    • Escalation of world oil prices triggered by a sharp rise in demand.
    • Uncertainties in the world oil market caused by wars and political instability.
    • Control of huge world oil reserves by a few countries, who sometimes hoard the product causing artificial shortage.
    • Rapid depletion of reserves thus lowering the supply.
    • Unequal distribution pattern of crude oil in the world.

    INSERT;   Photographs of long queues of motor vehicles at petrol stations waiting to refuel. People queuing at petrol station waiting to buy kerosene.
    What is the impact of the energy crisis in the world?
    An increase in oil prices leads to negative effects on the economies of oil-importing countries. The effects include:

    •  Increase in transportation costs. This causes inflation tendencies which lowers the people's purchasing power thus lowering their standards of living.
    • Increase in prices of commodities. This is caused by increased cost of production and transportation of goods as a result of high cost of oil. This too lowers the living standards of the people.
    • Reduction in government revenue. This is caused by the negative balance of trade as much of the country's foreign exchange is used for importation of oil. This lowers the economy.
    • High cost of agricultural inputs. A rise in cost of oil affects the agricultural sector when inputs including diesel used in tractors become costly. This leads to lower agricultural output when farmers cannot afford the cost of production. In turn there is food shortage which leads to famine.
    • Closing of industries. Industries that use petroleum by products as raw materials end up closing when these raw materials are no longer available. The workers in these industries are also laid off leading to unemployment.
    • Destruction of forests. When oil and oil products become expensive, people turn to use of charcoal and wood fuel as alternative source of energy. This may lead to desertification.

    The energy crisis can however, impact positively in the following ways:

    • The crisis motivates scientists to research into finding alternative sources of energy. In turn, countries invest in alternative sources of energy as a substitute to petroleum. For example, Kenya is investing in H.E.P., solar power, wind and geothermal power.

    INSERT:  A photograph / video clip of windmills at Ngong wind farm and solar panels on buildings.

    • Energy crisis motivates the producing countries to export more to capitalize on the high market prices.


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