ENERGY SOURCES AND DEVELOPMENT

Renewable energy sources

-these can regenerate or replenish themselves and can be used over and over again

-these cause little or no environmental pollution

-renewable energy sources include hydro electric power, biomass, wind, solar, geothermal,
tidal and wave power
-some of the resources for example forests and soils are if left to nature renewable but if used
carelessly by people can be destroyed by deforestation and soil erosion
-some of the energy sources like wind power, solar power and wave power are not affected by
human beings
Non renewable energy resources

-these are finite as their exploitation can lead to the exhaustion of supplies
-these are those energy sources which once used up will never occur naturally in the
environment
-therefore, there is great need to conserve or use them wisely e. g. by introducing substitutes
-examples include fossil fuels (oil, natural gas and coal)

Energy reserves
-these are known resources which are considered exploitable under current economic and
technological conditions
-oil and natural gas need advanced technology and high global prices to be exploited

-tidal and wave power still lacks the technology to be exploited

-Coal and wood fuel are found in abundance and are easy to exploit and develop
Fossil fuels
-are combustible materials made from fossilised remains of plants and animals

-once exhausted, fossil fuels deposits cannot be replenished hence they are referred to as non
renewable energy resources
-examples of fossil fuels are coal, oil and natural gas
Primary energy
-is energy derived directly from either renewable sources such as sun, wind and wood or fossil
fuels like coal and natural gas
Secondary energy

-refers to energy derived from processing other energy resources

-petrol from petroleum and coke from coal are examples of secondary energy sources
Commercial energy
-refers to energy produced for sale rather than direct use

Energy crisis
-is a situation where there is inadequate power supply in a place
-this results from the inability of the country to explore or use energy
-it is also an inadequate power supply in relation to demand in an area

Sustainable energy consumption

-refers to wise, responsible and careful use of energy while reserving for future generation
-refers to conservation and preservation of energy putting into consideration the fact that
resources run out
-it involves conservation and use of renewable resources

Resource endowment
-refers to availability of natural or manmade resources in a region which can be exploited for
the benefit of the people
Alternative energy sources

-is an energy source which comes to rival the existing type which may have detrimental effects
or may be facing exhaustion which as well may not be widely used e.g. tidal, solar and wind
Per capita energy consumption
-is the amount of energy used by an individual per year measured in kilowatts

Load shedding
-is a systematic way of distributing electricity by allocating some areas while others are
deprived
Transmission costs
-these are costs incurred in carrying electricity produced at a station to the consumer
Traditional fuels
-are often collected from common resources such as open land and woodland
-their collection and burning may create environmental problems e. g. firewood, biomass, peat,
cow dung
-these are cheap and are commonly used by LEDCs
Commercial fuels
-refers to fossil fuels which need advanced technology to be extracted e. g. coal, oil and natural
gas
-these are expensive and commonly used in MEDCs
POTENTIAL ENERGY SOURCES IN ZIMBABWE
b) Solar power

-the north and west regions of the country receive highest solar radiation
-most of the solar power is used in rural areas in service centres such as schools, clinics, police
stations and in urban areas for water heating
-the government has encouraged the use of solar water heaters so as to save electricity
-solar base stations have been installed by telecommunication companies such as Econet

b) Wind power
-Zimbabwe experience low winds speeds hence making generation of wind power difficult
-however, the slow wind speeds can be used for water pumping
-areas around Bulawayo and Eastern Highlands could have potential for large power generation
since most prevalent wind speeds are strong
c) Bio energy
-bio energy in Zimbabwe is obtained from the waste materials of sugar cane and animal waste
-two sugar cane crushing mills process more than 1.3million tonnes of bagasse to generate
electricity used by the sugar factories
-the timber industries have strong bio energy potential because they produce a lot of waste
-more than 200 biogas plants have been installed around Zimbabwe by Ministry of Energy
-biogas can be generated from livestock waste due to large population of livestock in Zimbabwe
d) Geothermal power
-in Zimbabwe geothermal power can be generated in areas of the Eastern Highlands which are
part of the rift Valley
e) Hydro electric power

-much of Zimbabwe’s electricity is produced at Kariba Dam Hydroelectric Power Station

-apart from the Kariba, there is a lot of hydro electric power potential along the Zambezi River
especially in Victoria Falls where there is largest curtain of falling water
ACTUAL ENERGY SOURCES

a) Fuelwood
-is the most domestic fuel in Zimbabwe in rural areas
-it is also used in the agricultural sector for curing tobacco
-large demand of wood fuel has led to deforestation in some parts of the country and
environmental problems such as erosion and diminishing wildlife
b) Coal
-Zimbabwe has large deposits of coal (3 billion tonnes of coal in 21 known deposits)
-coal is used to generate thermal power at Hwange Thermal Power Station and by industries
c) Liquid fuels

-Zimbabwe has no oil or gas resources of its own and is completely dependent on imports
-a pipeline from Mozambique port of Beira to Mutare provide the majority of Zimbabwe’s
petroleum and diesel
-some of the liquid fuels come from South Africa

d) HEP and thermal power

-electricity is generated at Kariba HEP station and Hwange Thermal Power Station
-three minor coal fired stations also provide electricity
-all coal fired stations are in need of major upgrades due to neglect and lack of maintenance
and this has led to frequent and long lasting power cuts
-the Zimbabwe Electricity Supply Authority (ZESA) is the country’s power generating and
distribution company
-electricity imports are also obtained from neighbouring countries such as South Africa and
Mozambique
DISTRIBUTION OF ENERGY SOURCES
-coal is mostly found in Asia Pacific region, USA, Australia and Russia
-oil is mostly found in Middle East which accounts for 60% of global reserves

-the countries with large oil reserves are Saudi Arabia, Kuwait, Iran and United Arab Emirates
-natural gas is found across the globe and the largest producing world regions are Europe,
Middle East and North America
-the large producers of HEP are China, Canada, Brazil and USA due to presence of perennial
rivers such as Yangtze, Amazon, Mississippi and Colorado
GLOBAL TRENDS IN ENERGY USE
-world energy is consumed mainly in the following fields
✓ In the homes for cooking, heating and air conditioning
✓ In transport systems for example petrol
✓ In agriculture for irrigation, power tractors and other machines
✓ In factories to run industrial machines
✓ To generate electricity for example coal and oil to generate thermal power
-MEDCs have higher levels of energy consumption than LEDCs

-USA consumes a third of world’s commercial energy

-LEDCs do not possess energy resources of their own and even with potential energy resources,
they have insufficient capital to develop them
-in LEDCs there is inadequate knowledge and technology to exploit available and known energy
resources
-the ever rising oil prices strain economies of LEDCs and the high oil prices make energy
inaccessible to the poor populations of the LEDCs
-LEDCs have low demand for commercial energy due to low levels of industrialization and
backwardness of their communities
-there is heavy reliance on traditional energy sources such as firewood and animal dung in the
LEDCs
-with high rates of urbanization and high cost of imported fuels, poor urban population resort to
use of wood fuel for cooking and heating as evidenced by massive deforestation around many
urban peripheries of the developing world
-this leads to air pollution and environmental degradation
-oil and natural gas are the main sources of energy in the Middle East
-HEP is an important source of energy and is the greatest in the South America and in Africa
because of presence of perennial rivers

-nuclear energy is not presently available in African and Middle East and has the smallest
contribution in the developing nations
-however, nuclear energy is most important in Europe, Eurasia and North Africa
FACTORS AFFECTING ENERGY USE

a) Availability and sustainability of resource

-some sources of energy such as coal and oil are dirty and non renewable whilst others are clean,
abundant and sustainable e. g. solar power
b) Cost of extracting and transporting

-some types of energy such as nuclear and oil are too expensive for less wealthy countries whilst
others are affordable and cheap to exploit e. g. coal and wood fuel
-other energy sources such as tides are uneconomical to use
c) Availability of technology
-some energy source such as nuclear are costly to develop because they require advanced
technology
-others such as wave energy are yet to be developed because the technology cost is beyond the
reach of many countries
d) Demand

-in less developed countries energy is required daily mainly for domestic purposes
-in more developed countries energy is needed for transport, agriculture and industry
-the MEDCs have a high demand for energy hence they produce large amounts of energy
everyday to cater for rising energy demand

e) Political decisions
-politics decides on the type of energy to utilize or develop
-politics can also decide whether to deny sale of energy to rival countries e. g. nuclear
f)Environmental concerns

-some types of fuels e. g. coal and oil contribute to greenhouse emissions and contaminate land,
air and water
-mining of coal disrupts the natural environment and endangers the natural habitat of animals
g) Competition from other forms of available energy
-in many countries there is a decline in the use of dirty source energy such as coal and oil due to
preference of cleaner sources of energy such as HEP and solar power
-in many European countries there is introduction of solar powered cars because petrol and
diesel lead to environmental problems such as greenhouse effect and global warming
h) Affluence of the market

-some sources of energy like nuclear are expensive and only afforded by rich nations such as USA
and Japan
-nuclear and wave power are unavailable in poor nations because they lack the technology and
capital to develop them

IMPACT OF UNEQUAL DISTRIBUTION OF OIL

a) Human migration
-large group of people often migrate to a places that have rich oil deposits e. g. Dubai and move
away from places that lack resources
b) Human settlement and population distribution

-people tend to settle and cluster in places with abundant oil reserves e. g. Middle East and Niger
Delta
c) Conflict and war
-many historical and present day conflicts and wars involve nations trying to control oil rich
territories e. g. the desire for oil resources has been the root of conflicts in Africa and Middle East
d) Wealth and quality of life
-oil rich nations have abundant wealth and high standards of living e. g. Libya and United Arab
Emirates

NON RENEWABLE ENERGY SOURCES

1. COAL
-coal is an important energy source and provided the basis for the industrial revolution in Britain,
Western Europe and USA

-coal is used by thermal power stations to generate electricity and by industries

-there are still large deposits of coal across the globe which are yet to be exploited
-there has been a decline in consumption of coal because the most easily accessible deposits of
coal have been used up
-the cost of exploiting coal has risen up due to expensive machinery needed and increased wages

-the demand for coal has fallen for industrial use due to introduction of oil and natural gas
-green pressures have also led to a decline in coal mining which creates dust and leaves spoil
heaps
-the use of coal to produce thermal electricity also releases Sulphur dioxide and carbon dioxide
which are blamed for acid rain and global warming
Advantages of coal
-it is a cheap source of energy
-it gives out a lot of energy

-it creates employment through mining

-it has many other industrial uses
Disadvantages of coal
-it causes a lot of air pollution
-it is a non renewable energy resource

-it is bulky and difficult to transport

-it is dirty
-carbon dioxide and Sulphur dioxide produces during combustion of coal leads to acid rain and
global warming

-pits and spoil heaps reduce the aesthetic value of the environment
2. OIL
-oil the world’s most influential commercial commodity with immense political influence
-oil comes from crude oil, which is a mixture of hydrocarbons with some oxygen, nitrogen and
Sulphur impurities
-some of the world’s largest transnational companies are oil companies e. g. Shell and BP
-oil like other fossil fuels, is not evenly distributed
-oil is found in harsh and hostile environments e. g. Arctic regions (Alaska), tropical rainforest
(Nigeria and Indonesia), deserts (Algeria and Middle East) and under stormy seas (North Sea)
-oil exploration and exploitation is expensive and it is costly to transport by pipeline and tankers
to world’s markets
-in the Middle East countries such as United Arab Emirates have experienced economic boom
due to oil mining
-over the past years new technology has been developed to exploit less accessible oil reserves
-oil production and distribution is affected by political and military decisions
-OPEC is a major influence in determining production and fixing oil prices

-oil is used in power stations to generate thermal power and by industries and transport
-oil is less harmful to the environment than coal but it still posses threats
Advantages of oil
-it gives out a lot of energy when heated

-it is cleaner than coal

-it is easy to transport through pipes
-it is a cheap source of energy
-it can power vehicles and has many industrial uses
Disadvantages of oil

-it causes land, air and water pollution

-it is a non renewable source of energy
-it is highly inflammable and dangerous
-oil leaks in pipelines pollutes beaches and kills wildlife and marine species e. g. Exxon Valdez in
1989
-explosion of tankers causes loss of human life e. g. Alpha Piper rig 1988
-oil tankers are hijacked by pirates e. g. Somalia 2008 and Iran 2019
3.NATURAL GAS

-natural gas is a fossil fuel and is derived from organic matter

-it is the fastest growing energy source because it is cleaner and environmentally friendly than
oil and coal
-like other fossil fuels such as coal and oil, natural gas is derived from plants, animals and micro
organisms that lived millions of years ago
-natural gas is found close to oilfields and is considered to be the cheapest and cleanest of the
fossil fuels
-the largest reserves of natural gas are found in Russia, USA and in the Middle East

Advantages of natural gas

-it is cleaner than coal and oil
-it has high energy output
-it has many domestic and industrial uses

-it is cheap to transport

Disadvantages of natural gas
-it is a non renewable energy resource
-it causes air pollution

-it is highly inflammable and dangerous

-it is difficult to store
-it is vulnerable to leaks and explosions
4. NUCLEAR ENERGY
-nuclear is derived from uranium

-compared with fossil fuels, uranium is only needed in small amounts

-uranium has a much longer lifespan than coal, oil and natural gas and can be moved more easily
and cheaply
-development of nuclear energy is very expensive and has been adopted by wealthy countries
lacking fossil fuels such as Japan, UK, France and USA
-it is a source of electricity and cannot be used for transport and heating
-although nuclear power stations produces fewer greenhouse gases than thermal, they do
present environmental risks

-when locating a nuclear station, the prime factor for consideration is safety
-sites that are suitable for a nuclear power station include:

• Near abundant water supply with an area of level ground

• Coastal and other waterside locations away from densely populated regions

Advantages of nuclear energy

-it has a high energy output
-it has a longer lifespan than fossil fuels
-nuclear power produces less greenhouse gases

-it reduces overreliance on fossil fuels

Disadvantages of nuclear energy
-nuclear accidents contaminate the water table e. g. Seven Mile Island of the USA
-nuclear plants are expensive to build and maintain and are therefore only built by wealthy
countries or countries with significant energy deficits
-nuclear power cannot be used for transport and heating
-emission of radio active waste leads to cancers such as Leukemia
-nuclear energy accidents can release radio active waste which may be dangerous after many
years
-it can be used by rogue states or terrorists to make destructive weapons
RENEWABLE ENERGY SOURCES
1.HYDRO ELECTRIC POWER
-HEP is the most widely used commercially produced renewable source of energy

-its generation requires a reliable supply of fast flowing water which may be obtained from
perennial rivers or from large reservoirs such as dams
-HEP generation involves building dams, constructing power stations, installing turbines and
erecting pylons and cables for electricity transmission

-the big four HEP producing nations are China, Canada, Brazil and USA and account for 50% of
the global total
Advantages of HEP
-HEP is a renewable source of energy

-it is a clean source of energy

-dams and other infrastructure has multi purposes e. g. Aswan Dam in Egypt
-HEP enhances urbanization as industrial towns grow around HEP stations e. g. Kariba town
-dams cool and provide moisture to the local environment
-once constructed, HEP stations are relatively cheap to maintain
Disadvantages of HEP
-HEP stations are expensive to build
-construction of large reservoirs can lead to large areas of vegetation being cleared e. g. Tucurui
in the Amazon Basin
-wildlife habitats are lost during creation of dams e. g. Kariba dam in Zimbabwe and Volta dam in
Ghana
-thousands of people are displaced and forced to move away from the dam’s catchment area e.
g. Three Gorges dam in China, Aswan in Egypt and Kariba in Zimbabwe led to relocation of
thousands of people
-there may be risks of flooding due to overflowing of dams and collapse of dam walls
-large dams cause earth tremors e.g. Kariba and Nurek dam in Tajikistan

-dams spread waterborne diseases e. g. Malaria and Cholera

-siltation cuts short the lifespan of HEP stations
-creation of dams reduces water downstream
-large areas of forests are submerged during the creation of dams hence releasing large
quantities of methane which lead to the greenhouse effect

Factors that promote HEP generation

-availability of steep gradients and gorge -like valley that minimize the construction costs and
gives a high head of water
-presence of mountainous terrain that results in high rainfall patterns due to orographic uplift of
warm moist air
-availability of open stretches upstream to accommodate large volumes of water in the reservoir
-presence of very hard and strong rocks that give the dam wall a strong foundation
-political stability and co-operation especially for large scale projects affecting more than one
country and requiring external financial assistance
-presence of a large market to justify and support such a major scheme
-presence of large amount capital investment for building and maintenance of the plant
2 SOLAR ENERGY

-is energy from the sun

-it involves tapping of sunlight using solar panels and batteries
-solar energy is a renewable energy source which is pollution free, efficient and limitless in supply
-solar power stations are expensive to construct
-tropical areas are more suited to solar power generation because of abundant amounts of
sunshine
-in temperate regions the solar energy is less favourable due to greater amount of cloud cover
and long hours of darkness in winter when the demand for energy is at its highest
Advantages of solar power

-it is cheap source of energy

-it is renewable and infinite
-it can be stored and used at night
-it is clean and helps to slow and stops global warming

Disadvantages of solar power

-solar collecting equipment and installation is expensive
-it is easily affected by clouds and varies from place to place
-sunshine hours vary from place to place and with seasons and areas with greatest energy supply
are remote deserts

-it is only good for small electrical appliances and is unsuitable for industrial machines
-it is difficult to store
3. WIND ENERGY
-wind is the most successful of the new renewable technologies

-it is generated through windmill blades that are tuned by wind

-the rotating blades are linked to turbines which produce electricity
-wind farms are best suited to places where winds are strong, steady and reliable e. g. areas of
higher ground and coastal areas

Advantages of wind power

-it is a renewable energy source
-wind energy is clean and pollution free
-it is relatively cheap to maintain
-wind farms create employment in rural areas
Disadvantages of wind power
-wind farms are ugly and reduce the natural beauty of the land

-it can only be used in areas where great wind speeds are experienced (it is a localized source of
energy)
-the turbines produce a lot of noise
-the turbines block/impair radio and television reception

-the turbines affect airport radar systems

-the turbines affect wildlife and the rotating blades kill birds
-suitable areas for windfarms are often near the coasts where land is expensive
4.GEOTHERMAL POWER

-geothermal energy is the natural heat found in earth’s crust in the form of steam, hot water and
hot rocks
-it is derived from hot springs and by tapping aquifers which contain natural hot water
-cold water can be pumped downwards where it is heated naturally and is then returned to the
surface as steam which can turn turbines and generate electricity

-pipes are installed to control and direct the movement of steam to turbines
-the steam turns the turbines which operate generators to produce electricity
-the steam is then pumped to cooling chambers where it is converted back to water
Advantages of geothermal power

-it is cheap to maintain

-it is renewable energy source
Disadvantages of geothermal power
-it pollutes the environment as carbon dioxide and hydrogen sulphide emissions are high

-it can only be constructed in volcanic areas (it has got limited sites)
-it can be destroyed by tectonic movements such as earthquakes and volcanic eruptions
-it is expensive to build as it needs a lot of capital investment
5.BIOFUEL/BIOENERGY
-it is obtained from organic matter e. g. crops, plants and animal waste
-it is the dominant form of energy in the developing world who use it for cooking and heating
-the most common type of biofuel is wood fuel

-the use of biomass is generally considered to be a carbon neutral process as the carbon dioxide
released in the generation of energy balances that absorbed by plants during their growth
-methane (biogas) produced during fermentation of animal waste is used as a domestic fuel
-ethanol produced in the fermentation of sugar is the most common biofuel globally especially
in Brazil and USA
-ethanol can be used in petrol engines when mixed with gasoline
-more recently there has been introduction of bio-diesel which comes from palm oil and jatropha
-the use of bio-diesel has led to increased forest clearance

Advantages of biofuel
-it is renewable as long as people replace plants
-it is a cheap source of energy
-resources can be grown locally
-decayed matter can be used as manure

Disadvantages of biofuel
-it needs to be blended with imported fuel
-it leads to massive deforestation
-it caused air pollution and greenhouse effect
-crops and trees take a long time to grow
6.WAVE POWER
-waves are created by transfer of energy from wind which blows over them
-in Western Europe winter storm waves from the Atlantic Ocean transfer large amounts of energy
towards the coast where it has the potential to generate energy
Advantages of wave power
-it is a renewable energy source
-it is clean and environmentally friendly
-it is abundant and widely available
-it reduces dependency of imported fuels
Disadvantages of wave

-it is only suitable to certain locations e. g. Coastal areas. Landlocked countries must find
alternative sources of energy
-large machines used to generate wind power destroy habitats for marine species hence leading
to extinction of some water species

-the equipment used to generate wind power disturb vessels on coastal areas such as cargo ships
and recreational vessels
-some coastal areas experience low wind speeds which fail to generate powerful waves
-harsh weather conditions such as cyclones destroy wave power stations

-wave energy generate a lot of noise which is unpleasant to people who live in coastal areas
-lacks adequate technology to be developed in the poor nations
CAUSES OF LOW ENERGY CONSUMPTION IN LEDCS
-high prices of oil make it difficult for poor nations to access oil
-low level of industrialization, energy is only used for domestic use only as most of the industries
are closed
-heavy reliance on traditional energy sources such as firewood and animal dung, most people are
poor and cannot afford to pay for electricity
-inadequate technology and technical know on how to exploit available and known energy
sources, most people exploit easily accessible energy resources such as firewood
-inadequate capital to develop energy supplies
-fewer commercial activities which require electricity
WAYS OF CONSERVING ENERGY AND SUSTAINABLE USE OF ENERGY

-introduction of alternative sources of energy which are clean and environmentally friendly e. g.
solar power and bio energy
-education and awareness campaigns on energy conservation
-establishing small scale hydro electric power stations e. g. in Honde Valley

-importing electricity from other countries e. g. from Eskom in South Africa and Cobora Bassa in
Mozambique
-development and use of energy saving appliances and devices
-practising afforestation and reforestation e. g. woodlots for wood fuel
-passing legislation on clearing and trading on firewood

-use of energy saving bulbs which are energy efficient e. g. fluorescent bulbs
-switching off some electrical gadgets to save electricity
-introduction of load shedding timetables
-preventing heat loss through roof and wall insulation

-adopting gas and reducing the number of oil and coal fired power stations
ROLE OF ICT IN ENERGY PRODUCTION AND CONSUMPTION
-computerised processes reduce manual labour e. g. in billing and meter reading (cash power)
-office automation improves communication between consumers and production plants by use
of telephone, fax, Internet, email and cellphones
-computers help in planning load shedding timetables for different areas
-telephone and radio informs customers on load shedding timetables and faults