UNIT 10: POWER AND ENERGY PRODUCTION IN THE WORLD
UNIT 10: POWER AND ENERGY PRODUCTION IN THE
WORLD
Key unit competence:
By the end of this unit, I should be able to evaluate the success of sustainable
development projects in power and energy production in different parts of theworld.
10.1. Sources and forms of energy used in the world
Learning activity 10.1
1. Make a short tour in the school and the surrounding environment and
answer the following questions:
i. Identify the activities that require power and energy at your school.
ii. Describe the forms of power and energy needed for each activity
identified above.
2. Discuss the sources of power and energy exploited and not exploited in
Rwanda.
10.1.1 Classification of energy resources
There are two main categories of energy resources:
• Non-renewable resources: These are resources of energy without the capacity
of replenishing themselves after being used. When used they get exhausted
and cannot be re-used. They include minerals, natural gas, oil and coal.
• Renewable resources: They are inexhaustible. These are resources of energy
with the capacity of replenishing themselves after being used. They include
water, wind, solar, plants (biomass) and animals (biogas).
10.1.2. Non-renewable energy sources
Non-renewable energy resources are available in limited supplies. This is usually due
to the long time it takes for them to be replenished. They include nuclear energy and
fossil fuels energy resources like coal, oil and natural gas.
a. Nuclear energy (Uranium)
Nuclear energy is energy obtained from uranium through a chain reaction. When
it was realized that when the nucleus of an atom is bombarded by electron it
disintegrates and releases enormous quantity of energy, two thoughts came in the
mind of rational man:
• to build an atomic weapon, and;
• to generate electricity.
Thus, mankind has developed the art of both. The release of energy by this process is
known as fission. Based on this process scientists build reactors in which controlled
fission went on to produce energy (heat) and this heat generated electricity.
Generation of electricity involves a lot of technical know-how and so far, only highly
developed countries have been able to master it. Thus, the USA, Canada, the UK,
France, Japan, Germany are the largest producers of electricity by nuclear fission.
Nuclear energy contributes about 9% of all energy produced in USA, though it
produces 50% of all electricity generated by nuclear energy worldwide. France
derives about 75% of its electricity from nuclear energy, 18.5% in Britain, 15% in
Japan and 7% in German. Among the developing countries India is the leader
producing 3% of her total requirements from nuclear power plants.
b. Coal
Coal is a sedimentary deposit formed by the slow action of heat and pressure on
plant remain buried in the long past. It is a mechanical mixture of carbon, hydrogen,
nitrogen, sulphur, etc. It is the content of carbon which determines the quality of
coal.
i. Types of coal
The amount of fixed carbon and hydrocarbons forms the basis of classification of
coal into various types. The following kinds of coal are generally recognized:
• Anthracite: It is a hard and dense coal which is relatively free from iron
compounds and moisture. It is made by 95 % of carbon.
• Bituminous: It is unusually black and highly lustrous. The moisture content is
relatively low. The fixed carbon content ranges from about 50 to over 80% and
that volatile matter from 40 to 15%.
• Lignite: It is also known as brown coal. The higher grades vary from dark
brown to almost black. It is characterized by high moisture content, generally
about 40%. The fixed carbon content is also 40%. The structure is fibrous, and
sometimes woody.
• Peat: It occurs in bogs, especially in areas of cool temperate climates. This isyoung coal which consists of partly decomposed vegetation.
ii. Uses of coal
The coal can be used:
• in thermal generators to produce thermal electricity.
• as a domestic fuel for heating and indirectly in the form of a gas and electricity.
• in iron smelting e.g. through use of metallurgical coke in blast furnaces.
• to provide a number of raw materials for the chemical industries like coal gas,
coal tar, benzele and sulphate of ammonia.
c. Petroleum (oil)
Petroleum is an inflammable mixture of oil hydrocarbons with very complex
properties. Petroleum literally means ‘rock oil.’ It exists underground in solid, liquid
and gaseous form. Accumulations of petroleum are found in underground fields,
pools or reservoirs of sedimentary rock formations.
i. Three grades of crude oil according to gasoline yields
• Paraffin - base oil has high percentage of methane (highest yields)
• Mixed-base oil has high percentage of naphthene (intermediate yields)
• Asphalt - base oil has heavier hydrocarbons (lowest yield)
ii. Uses of petroleum
Petroleum can be used:
• for heating homes and hearths;
• as industrial power to drive/move engines and for heating furnaces and
producing thermal electricity;
• as transport power for driving railways, motorcars, ships and aeroplanes;
• as lubricants of machines especially high-speed machines;
• as a raw material in various petro-chemicals industries, such as syntheticrubber, synthetic fibres, fertilizers, medicines.
d. Natural gas
Natural gas is a naturally occurring hydrocarbon gas mixture consisting primarily of
methane, but commonly including varying amounts of other higher alkanes, and
sometimes a small percentage of carbon dioxide, nitrogen, hydrogen sulfide, or
helium.
The world’s proven reserves of natural gas are estimated at about 700 trillion cubic
feet. The USA (40%), the Middle East (23%), and the former USSR (11%). Most of the
rest is in northern Canada, Europe and Venezuela. Much smaller amounts are widely
scattered in several countries including Mexico, South American countries, Pakistan,
china, Indonesia and Australia. Nigeria is the first petroleum producing country in
Africa.
Natural gas may occur with or without petroleum. Where gas occurs in association
with oil, it is generally found in increasing amounts at the greater depths that needs
to be drilled.
Natural gas (Methane) as a fuel may be used for cooking, heating and even to
generate electricity. It has the advantage that it can be pumped through pipes from
wells to consumption sites. It is also a “clean fuel”. This means that it causes less air
pollution. Natural gas can be shipped in liquid form, called liquefied natural gas.
10.1.3. Renewable energy sources
Renewable energy is the energy that is generated from the resources that are
naturally replenished on a human timescale, such as sunlight, wind, rain, tides, waves
and geothermal heat. Renewable energy often provides energy in four important
areas: electricity generation, air and water heating or cooling, transportation and
rural energy services.
a. Wind energy
Wind power is an indirect form of solar energy that can be used to produce electricity.
Wind is an almost unlimited, free, renewable, clean and safe source of energy. It has a
moderate net useful energy yield and is based on fairly well developed technology.
As we can see it from the figure below, the process of the production of energy
from the wind is the following: usually a propeller blade is mounted on a tower. The
blade is connected onto an electric generator. As wind blows, the blade spins and
turns the generator which produces electricity by converting the kinetic energy of
the wind into electric energy. A suitable site for a wind turbine depends on the local
wind conditions.
b. Water energy
This is the energy produced from running water. Usually, a dam is constructed along
a river to store water. The water is then made to fall over a steep gradient. It then
passes through a turbine hence spinning the blades of the turbine. Rotation of theblades causes the turbine to turn an electric generator that produces electricity.
Hydro-electrical power energy requires the following physical and economic
conditions:
i. Physical conditions
• A seismological less sensitive area.
• High quantity of water supplied by fairly heavy rainfall distributed throughout
the year.
• Great altitude with steep slope to enhance water velocity.
• Existence of rapids and falls favour the development of power by increasing
the velocity of stream.
• Narrow steep-sided valley to facilitate dam construction.
• A hard rock for firm foundation.
• Existence of lakes or space for water reservoir.• The absence of coal, petroleum, etc., expedites the development of waterpower.
ii. Economic Conditions
• Market: Large demand for hydroelectric power;
• Huge capital outlay;
• Technological knowledge and skill and• Transport facility
c. Solar energy
Breeder reactors, fusion reactors and solar energy are the only energy alternatives
that could support high energy generation indefinitely. However, breeders have
potentially serious environmental and economic problems and nuclear fusion is so
complex, it can never be economically feasible. In contrast solar energy is abundant,
clean, safe and virtually inexhaustible free fuel.
If the direct sunlight falling on the earth in only 3 days is concentrated and converted
to useable form of energy, it would equal all of the energy in the earth’s known
reserves of coal, oil and natural gas.
The figure below shows the process of solar energy production. A greenhouse uses
panels of transparent glass to trap solar energy. Another way of tapping solar energyis by use of solar cells. This transforms sunlight directly into electricity.
d. Biomass
Many people consider the wind and the sun as the main forms of renewable energy.
However, biomass (plant material and animal waste) is the oldest source of renewable
energy, used since our ancestors learned the secret of fire.
Biomass is a renewable energy source for the two reasons: first the energy in it comes
from the sun, second, biomass can re-grow over a relatively short period of time
compared with the hundreds of millions of years that it took for fossil fuels to form.
The generation of energy starts through the process of photosynthesis. Through this
process, chlorophyll in plants captures the sun’s energy by converting carbon dioxide
from the air and water from the ground into carbohydrates—complex compounds
composed of carbon, hydrogen, and oxygen. When these carbohydrates are burned,
they turn back into carbon dioxide and water and release the energy they captured
from the sun.Bio-mass energy includes: wood fuel, Bio-gas and Gasohol.
i. Wood fuel: This is a very important source of energy in third world
countries. The wood obtained from forests is either used directly or
converted to charcoal.
ii. Waste products (Bio-gas): This is a flammable gas produced by microorganisms, when organic matter is fermented under specific temperatures,
moisture content and acidity. It is mainly composed of methane which
burns with a blue flame.
iii. Gasohol: Plant material may be converted to alcohol which is a fuel.
Wood, wood wastes and garbage can be heated to produce methanol.
Most plants containing starch and sugar like sugarcane and cassava can
be converted to ethanol. Corn, corn stalks, manure and sewerage can be
fermented and distilled to give ethanol. Both methanol and ethanol are
directly burned as a fuel.
e. Geothermal
Geothermal energy is produced when rocks lying deep below the earth’s surface are
heated to high temperatures by energy from the decay of the radioactive elements
in the earth and from magma. Geothermal energy can be considered as renewable
source of energy if deep underground heat flows can be tapped.
Geothermal energy can either be used for heating water, directly and space heating
needs in agriculture and for domestic purposes or it can be converted into electricity.
i. Wood fuel: This is a very important source of energy in third world
countries. The wood obtained from forests is either used directly or
converted to charcoal.
ii. Waste products (Bio-gas): This is a flammable gas produced
by microorganisms, when organic matter is fermented under specific temperatures,
moisture content and acidity. It is mainly composed of methane which
burns with a blue flame.
iii. Gasohol: Plant material may be converted to alcohol which is a fuel.
Wood, wood wastes and garbage can be heated to produce methanol.
Most plants containing starch and sugar like sugarcane and cassava can
be converted to ethanol. Corn, corn stalks, manure and sewerage can be
fermented and distilled to give ethanol. Both methanol and ethanol are
directly burned as a fuel.
e. Geothermal
Geothermal energy is produced when rocks lying deep below the earth’s surface are
heated to high temperatures by energy from the decay of the radioactive elements
in the earth and from magma. Geothermal energy can be considered as renewable
source of energy if deep underground heat flows can be tapped.
Geothermal energy can either be used for heating water, directly and space heatingneeds in agriculture and for domestic purposes or it can be converted into electricity.
f. Tidal energy
Tidal energy or tidal power is a form of hydropower that converts the energy
obtained from tides into useful forms of power, mainly electricity. Although not yet
widely used, tidal energy has potential for future electricity generation.
As the tide rises and falls water flows into and out of bays and estuaries. If the bays
and the estuaries can be closed by a dam the energy in the tidal flow can be extracted
four times a day and used to spin a turbine to produce electricity.
Although all coastal areas are subject to some tidal changes, only those few areas
with a large enough tidal range of some four to five meters are potential sites for tidal
power plants. These sites are located for most part on both sides of North Atlantic,
the English Channel and the Arctic coast of the C.I.S. a few developing countries
such as Argentina and India also have some tidal power potential.
There are presently two tidal power projects: one in Commonwealth of IndependentStates (C.I.S) and the other in France.
Application activity10.1
i. Describe the sources of power and energy exploited in Rwanda.
ii. Indicate the main hydro-electric power stations in Rwanda.
iii. Suggest other alternative sources of power and energy that can be used in
the world.
iv. What types of energy sources promote environmental sustainability?
10.2. Factors and importance of power and energy production in the
world
Learning activity 10. 2
1. Describe the areas of power and energy production in Rwanda and
showing the reasons of their geographical location.
2. What are the challenges that Rwandans would be facing if those areasidentified above were not there?
10.2.1 Factors favouring power and energy production in the world
The following are the major factors influencing power and energy production in the
world:
• Availability of market is a pre-requisite for the power and energy production.
For example, densely populated areas, industrially and commercially advanced,
have a great demand for electricity.
• Availability of capital to invest in power and energy production. Production of
energy/power, setting up power houses, and transmitting electricity through
wires to the areas of consumption require a lot of capital in terms of money.
• A high degree of technical knowledge and skills.
• The amount of energy to be produced depends on the potentiality of power
and energy generator. For example, the amount of hydro-electrical power to
be produced depends on the quantity of water and velocity of stream. The
latter, in turn, depends upon the gradient of the stream.
• The natural environment of the area where the power and energy will be
produced and transported such as the topography (e.g. nature of terrain and
slope), climate (e.g. amount of rainfall, sunshine), hydrology (e.g. quantity and
quality of water), vegetation (e.g. amount of biomass) affect the production ofpower and energy.
10.2.2. Importance of power and energy in the development of the world
Power plays a role in the development of a country in different ways such as:
• Earns foreign exchange: Energy can be exported in neighboring country
and in that way, it is contributing to the earning of foreign exchange. The
economies of many countries are depending on the production of petroleum
which is the most used worldwide source of energy. For example, the DRC
earns $40 million annually through exports of electricity from Inga dam plant.
• Development of industrial sector: The engine that moves the industrial sector
is energy and without it the whole sector would ground to a standstill. Most
industries use petroleum and its by-products to run the machines. Electricity
is also used to run machines while wood fuel is used in various processing
industries such as tea processing.
• Development of transport sector: Petroleum is used in road transport, water
transport and air transport meaning that it is the basic element in transport.
• Creation of employment opportunities: The generation of electricity is
offering employment to a good number of people.
• Development of Agricultural sector: Solar energy is used to dry grains and
other produce such as tobacco, cocoa and coffee. Petroleum and its products
are used to run water pumps and other agricultural machinery. Wind power is
used in dry regions to pump water for irrigation.
• Improvement of welfare of people in general: Various forms of energy is
used for various purposes such as cooking, lighting and heating. In the rural
areas, the main sources of energy are firewood, charcoal and liquid petroleum.
In Urban sector, charcoal, kerosene, liquid petroleum, gas and electricity are
used.
Application activity 10.2
1. Describe requirements for Rwanda to fully exploit its available power and
energy resources.
2. Visit your local industrial areas and identify the role of power and energy
in an industry.
10.3. Problems and possible solutions for power and energy
Learning activity10.3
Visit a power station in your environment and do the following:
i. Identify the problems of power productionii. Suggest the possible solutions to the identified problems.
10.3.1 Problems hindering the development of power and energy in the world
The energy crisis is still experienced in different parts of the world. This is due to the
following reasons:
• Coal has some inherent problems. Petroleum is not going to last long.
Hydroelectricity has its own limits and nuclear energy has some political
problems for it to be socially accepted worldwide because of the risks of its
catastrophes.• Overdependence on oil and its products. Many countries rely on petroleum10.3.2 Possible solutions for power and energy in the world
and petroleum products in industrial, transport and agricultural sectors. It
therefore becomes quite difficult to switch to other sources when there is a
problem with the supply of oil.
• Economic and political embargoes fixed by the rich countries. For example, in
1973 the oil producing countries in the Middle East imposed oil embargo on
USA because of its interference in the Israel and Palestine war.
• Increase in oil prices imposed by the Oil Producing and Exporting Countries
(OPEC).
• Depletion of wood fuel due to overexploitation of forests.
• Exhaustion and deepening of coal mines. Coal is a non-renewable source
of energy. Its continuous use leads to the deepening of the mines hence its
exhaustion. Consequently, the cost of extraction increases leading to high
prices of coal in the world market.
• Environmental pollution: Some sources of energy like coal and petroleum
are sources of Carbon dioxide which is emitted in atmosphere. The increase
of carbon dioxide in atmosphere leads to ozone layer depletion and climatechange with their consequences.
As the energy is used at a very high rate and people will continue to do so in the
future, there is no doubt that it will be exhausted one day. Since our energy resources
are limited, certainly there is a need to do something about it like:• Move towards renewable resources: The best possible solution is to reduceApplication activity 10.3
the world’s dependence on non-renewable resources and to improve overall
conservation efforts. Much of the industrial age was created using fossil
fuels, but there is also known technology that uses other types of renewable
energies – such as steam, solar and wind. The major concern is not so much
that we will run out of gas or oil, but that the use of coal is going to continue to
pollute the atmosphere and destroy other natural resources.
• Buy Energy Efficient products: Replace traditional bulbs with fluorescent
tube lights CFL’s and light emitting diode (LED’s). They use less watts of
electricity and last longer. If millions of people across the globe use LED’s and
CFL’s for residential and commercial purposes, the demand for energy can go
down and an energy crisis can be averted.
• Energy Simulation: Energy simulation software can be used by big corporates
and corporations to redesign building unit and reduce running business
energy cost. Engineers, architects and designers could use this design to come
with most energy efficient building and reduce carbon footprint.
• Government may come in and improve on public transport efficiency so as to
reduce the need to use personal vehicles to reduce the use of petroleum.
• On the domestic front, energy conservation can be achieved by making
electrical appliances like refrigerators, television, electric cookers more energy
efficient. This can be supplemented by switching of electricity gadgets when
not in use.
• Educating the public about the importance, the conservation and thesustainable use of energy resources.
This is an extract of an interview with Wilson Karegeya, a firm’s director for
commercial services, Rwanda Energy Group held with iPAD Rwanda Power &
Infrastructure Investment Forum in Kigali.
This interview was conducted two months before splitting EWSA into WASACand REG. Read it carefully and answer the questions related to it.
Let’s start with an update on the reform of the energy and water organisations
in Rwanda.
Rwanda Energy Group today was still EWSA two months ago. EWSA was the Energy,
Water and Sanitation Authority, a government parastatal, which they thought
splitting the organisation would ensure more efficiency, better and quick service
delivery. So it was split two months ago,
forming two corporations: one for water, the Water and Sanitation Corporation,
headed by a Managing Director. It was a department in EWSA and is now a standalone
company and still 100% owned by government. There is also the Rwanda Energy
Group (REG), which will specifically deal with energy projects. REG also has two
subsidiaries, the Energy Development Corporation Ltd and the Utility Corporation.
The Energy Development Corporation will mainly
What do you hope to achieve in the next 12 months?
We have now embarked on asset separation; EWSA had a lot of assets that need
to be shared between the water company and the electricity company. There are
issues of accounts and fixed assets like land and buildings that need to be split and
shared. That is what the new companies are doing right now. We are being assisted
by Price Waterhouse and some other specialised companies to make sure the reform
is done well for better service delivery.
And we expect, of course, more specialisation for these companies. The water
company will now specialise in making sure that they deliver clean water to the
population. They will be less distracted because they will be mainly focused on
providing clean water. And the electricity company will now not be overstretched,
looking into water and electricity but looking specifically into electricity projects,
so I expect more focus for these companies that will lead to better service delivery.
The energy projects that you will invest in, can you highlight specific challenges
and how
you will overcome them? One challenge is that we were used to government
investments where government invests in energy projects. We have now adopted
an approach to involve the private sector more in the generation phase of it: where
we identify projects that need to be developed, advertise them, attract private
investors, (IPPs) and negotiate the power purchase agreements with them, once we
agree and sign the contract, the project is up and running. Where I see challenges
is in the contract management. It is an issue that we are not used to working with
IPPs. Although you sign a PPA with an independent power producer, it is more about
managing the contract from day one up to the last day of the contract. So that is a
challenge there but we hope to overcome it by training our staff to make sure they
know how to deal with IPPs, know what to expect and when and what the IPP has todeliver. That is very important.
In terms of generation capacity in Rwanda, what is currently available and how
much are you projecting?
Currently we are at 110 megawatts capacity and we expect to generate up to 563
megawatts by 2017. That is the target we have. There are on-going projects that will
enable us achieve this targeted megawatts and some are nearing completion. We
have also taken the direction of utilising the regional interconnectors to be able to
share power with the neighbouring countries. We are currently negotiating a PPA
with Kenya aiming at purchasing power from Kenya through Uganda.
Power generation goes hand in hand with other infrastructure development
such as roads, rail etc. what are the plans there?
In the transmission sector we have also started using private developers. We recently
advertised a tender to attract investors to come and do the transmission lines and
improve the networks as we expand the capacity. Of course, there is a need to
improve the network, so we are doing that concurrently. What is a day like in Rwanda
in terms of electricity supply? Until recently there weren‘t many power outages in
Rwanda. But now industry is growing and the demand for energy is growing and
we are striving every day to increase the capacity to serve all our customers, be it
investors, industrial or domestic. Of course, you get investors who come to us saying
―I want 5 megawatts, I want 15 megawatts, I want up to 10 megawatts‖, so you
have to work hard to make sure you use all the resources available to provide such
electricity.
A recent example is a new cement factory that has asked for up 15 megawatts,
and we have a total capacity of 110 megawatts for the whole country. So you can
imagine how hard we have to work. The good news is that we have secured the
power the factory requires.
Who looks at tariffs and the regulation around tariffs?
It is RURA (the Rwanda Utility Regulatory Agency). But if we are attracting investors
for projects above 5MW, we negotiate a tariff. For projects below 5 megawatts, there
is a feed in tariff set by RURA. For big projects, Rwanda Energy Group negotiates
with the developer and agrees a tariff at which it will supply electricity.
What is the situation with residential access to power?
For now, the residential users are connected and satisfied. The challenge we are
facing is the new industries that are emerging. Otherwise the domestic customers
had no issues so far. Perhaps they might have to start competing for the insufficient
power that we have – to share this among the commercial and domestic clients that
we have. But we are working very hard to bridge the demand gap that is growingday by day
What do you see happening in the East African region in the next five years?
My personal view is that if the current trend of cooperation among the East African
member States continues, I see success. When I look at the engagement between
member countries, sharing power, that is success. When I see the opening of borders
for trade, that is success, and opening of borders for human capital, that is success. Ifthis trend is maintained I see a powerful East African Community.
Extracted from: ESRI AFRICA: AFRICA‘S POWER JOURNAL, Published on September 10, 2014
