TABLE OF CONTENTS
Foreword ................................................................................................................................... 1
1. Basic Introduction to Energy ....................................................................................... 4
1.1 Energy Forms and Conversions .......................................................................... 4
1.2 Energy and Power ............................................................................................... 5
1.3 Dimensions and Units of Energy and Power........................................................ 6
1.4 More on Energy Conversions and Efficiency ....................................................... 7
1.5 Energy Flows..................................................................................................... 10
1.6 Primary Energy Sources.................................................................................... 12
1.7 Energy Terminology .......................................................................................... 13
2. Basic SI Units, Prefixes, and Derived SI Units Used ................................................ 15
2.1 Basic SI Units .................................................................................................... 15
2.2 SI Prefixes ......................................................................................................... 15
2.3 Most Common Derived SI Units......................................................................... 16
2.4 Conversion of Non-SI Units to SI Units .............................................................. 16
3. Energy Accounting ..................................................................................................... 23
3.1 Equivalence and Replacement Values .............................................................. 23
3.2 Energy Balances ............................................................................................... 24
3.3 Energy Auditing ................................................................................................. 27
4. General Energy Data ................................................................................................... 29
4.1 World Energy Production and Consumption ...................................................... 29
4.2 Biomass Energy Consumption in RWEDP Member Countries........................... 33
2
,5. Fuels and Combustion................................................................................................ 35
5.1 Chemical Composition....................................................................................... 35
5.2 Moisture Content ............................................................................................... 36
5.3 Ash Content....................................................................................................... 38
5.4 Heating Values .................................................................................................. 39
5.5 Bulk Density....................................................................................................... 41
5.6 Fuel Characteristics ........................................................................................... 43
6. Wood Production Figures .......................................................................................... 44
7. Electricity Production and Consumption .................................................................. 46
8. Transportation............................................................................................................. 54
9. Energy Intensity .......................................................................................................... 55
10. Greenhouse Gases ..................................................................................................... 56
11. Air Emission Standards.............................................................................................. 58
12. Glossary of Energy and Environmental Terms ......................................................... 71
3
, 1. BASIC INTRODUCTION TO ENERGY
It is not unusual to hear colleagues, friends or family members say “I’ve got no energy today!”
when they don’t feel up to completing an assignment, playing sport or washing the dishes. This
everyday expression is actually very close to the scientific definition of energy. Energy is the
ability (or capacity) to do work. The word “work” here, to a scientist or engineer, has a much
broader meaning than simply going to the office or factory. However, non-technical people can
still think of energy as the ability to do all the hundred and one diverse things we might need or
want to do in our daily lives, from switching on a light to building a house.
Energy itself is not a thing or substance but an idea, a theoretical concept, used to connect
diverse processes, such as burning fuels, propelling machines or charging batteries, and to
explain various observations about these processes. Central to the concept of energy is that
processes which might at first sight appear to be very different, like those referred to in the
previous sentence, actually have a number of common features. Describing these common
features leads us to a greater understanding of what energy is.
1.1 Energy Forms and Conversions
A basic concept about energy is that while it has many forms (see Box 1.1), and can be
converted from one form to another (though some of the conversions would have no practical
value) or transformed from one grade of the same energy form to another (for example from
high temperature heat to low temperature heat), it can never be “used up”, and the actual
amount of energy stays the same. This is the basis of the First Law of Thermodynamics: in
any process involving energy,
BOX 1.1 FORMS OF ENERGY the total quantity of energy is
Kinetic energy: energy possessed by a moving object, such as conserved.
wind or water in a stream. Speed and mass of the object influence
the amount of kinetic energy. The faster the wind blows or the However, from our
more water flowing in a stream the more energy is available. observations of normal life, we
Potential energy: energy possessed by an object’s position know that in practical terms,
relative to the earth’s surface. This is stored energy which if the energy does run out. Batteries
object falls is converted into kinetic energy. For example, water in, for example, a torch
behind a dam: the higher the dam or the greater the amount of
eventually stop producing
water, the higher the potential energy.
Thermal energy (heat): A form of kinetic energy due to the electrical energy and have to
random motion of the atoms or molecules (the building blocks) of be replaced. What has actually
solids, gases or liquids. The faster the atoms or molecules move, happened is that the torch’s
the greater the thermal energy of the object, usually described as bulb has converted the
the hotter the object is. electrical energy into light – the
Chemical energy: A form of energy stored in atoms or molecules. energy form it is designed to
This energy is usually utilised by converting into heat (combustion) produce – and, to a large
or electrical energy (batteries). extent, waste heat. The original
Electrical energy: Most familiar in the form of electricity, which is
the organised flow of electrons (one of the building blocks of an
chemical energy stored in the
atom) in a material, usually a metal wire. battery has not disappeared, it
Electromagnetic energy (radiation): A form of electrical energy has just radiated into the
which all objects, in different amounts, emit or radiate. The most environment, where we can no
familiar forms are light and sound. longer make use of it. The
Mechanical energy: The energy of rotation usually associated energy may be lost to the
with a rotating shaft. system (the torch and battery),
4
, but the total amount of energy is the same before and after. It should be noted here that we
tend to focus on the energy form we want (the useful energy – the light in our example) and
regard the other as wasted (the heat), and so we neglect or overlook it. This can be an
expensive mistake, and energy conservation efforts pay a lot of attention to reducing the size of
this waste.
Energy conversions are just the ways in which we harness and utilise energy. For example, we
convert the potential energy of water stored in a dam into the mechanical energy of a turbine,
which in turn is converted into electrical energy. To pump water up from a well we do the
reverse. In everyday English we talk about “generating” and “consuming” energy, especially
when discussing electricity. These are, in fact, scientific impossibilities – what we are actually
describing is converting one form of energy to another. By generating electricity we usually
mean converting the chemical energy stored in a fuel such as coal or oil, by combustion into
heat energy, which in turn is converted into the mechanical energy of a turbine, and then into
electricity. What we in fact consume are fuels, which are forms of stored chemical energy.
1.2 Energy and Power
When utilising an energy conversion we are usually concerned with two things: the quantities of
energy involved and the rate at which energy is converted from one form to another, or
(particularly in the case of electricity) transmitted from one place to another via a medium, such
as water or high-voltage cable. The rate per second at which energy is converted or transmitted
is called the power. Thus there is a mathematical relation between the two concepts:
energy
energy = power x time or power =
time
In qualitative terms, this means that if you have a given quantity of energy, the greater the rate
at which you use it, the larger the amount of power produced. Take, for example, the chemical
energy stored in a tank of petrol, which, by a
succession of conversion processes, eventually
becomes the kinetic energy of the moving car. BOX 1.2 RELATIONSHIP BETWEEN
The more petrol allow into the engine per intake ENERGY AND POWER
stroke (by depressing the accelerator), the more At what rate per hour does a 1 kW heater
power the engine will produce and the faster the convert electrical energy into heat?
car will move. Another way to look at this is that the
more power you want from the engine, the quicker energy = power x time
you will use up the fuel. 1 kW is 1,000 watts
Since 1 watt is 1 joule per sec
In everyday English, the words “power” and 1,000 watts is 1,000 joules per sec
“energy” are often used interchangeably. If the In one hour there are 3,600 seconds
meaning is clear in the context, then a lack of
Substituting in the equation
scientific accuracy is not a problem. However, in energy = 1,000 x 3,600 joules
energy planning it is vitally important you are clear = 3,600,000 joules
which you mean. = 3.6 MJ
When describing energy conversions, the energy
Therefore a 1 kW heater converts 3.6 MJ of
resources undergoing transformation are usually electrical energy into heat per hour.
characterised in terms of their quantities, and the
conversion equipment in terms of the amount of
5
Foreword ................................................................................................................................... 1
1. Basic Introduction to Energy ....................................................................................... 4
1.1 Energy Forms and Conversions .......................................................................... 4
1.2 Energy and Power ............................................................................................... 5
1.3 Dimensions and Units of Energy and Power........................................................ 6
1.4 More on Energy Conversions and Efficiency ....................................................... 7
1.5 Energy Flows..................................................................................................... 10
1.6 Primary Energy Sources.................................................................................... 12
1.7 Energy Terminology .......................................................................................... 13
2. Basic SI Units, Prefixes, and Derived SI Units Used ................................................ 15
2.1 Basic SI Units .................................................................................................... 15
2.2 SI Prefixes ......................................................................................................... 15
2.3 Most Common Derived SI Units......................................................................... 16
2.4 Conversion of Non-SI Units to SI Units .............................................................. 16
3. Energy Accounting ..................................................................................................... 23
3.1 Equivalence and Replacement Values .............................................................. 23
3.2 Energy Balances ............................................................................................... 24
3.3 Energy Auditing ................................................................................................. 27
4. General Energy Data ................................................................................................... 29
4.1 World Energy Production and Consumption ...................................................... 29
4.2 Biomass Energy Consumption in RWEDP Member Countries........................... 33
2
,5. Fuels and Combustion................................................................................................ 35
5.1 Chemical Composition....................................................................................... 35
5.2 Moisture Content ............................................................................................... 36
5.3 Ash Content....................................................................................................... 38
5.4 Heating Values .................................................................................................. 39
5.5 Bulk Density....................................................................................................... 41
5.6 Fuel Characteristics ........................................................................................... 43
6. Wood Production Figures .......................................................................................... 44
7. Electricity Production and Consumption .................................................................. 46
8. Transportation............................................................................................................. 54
9. Energy Intensity .......................................................................................................... 55
10. Greenhouse Gases ..................................................................................................... 56
11. Air Emission Standards.............................................................................................. 58
12. Glossary of Energy and Environmental Terms ......................................................... 71
3
, 1. BASIC INTRODUCTION TO ENERGY
It is not unusual to hear colleagues, friends or family members say “I’ve got no energy today!”
when they don’t feel up to completing an assignment, playing sport or washing the dishes. This
everyday expression is actually very close to the scientific definition of energy. Energy is the
ability (or capacity) to do work. The word “work” here, to a scientist or engineer, has a much
broader meaning than simply going to the office or factory. However, non-technical people can
still think of energy as the ability to do all the hundred and one diverse things we might need or
want to do in our daily lives, from switching on a light to building a house.
Energy itself is not a thing or substance but an idea, a theoretical concept, used to connect
diverse processes, such as burning fuels, propelling machines or charging batteries, and to
explain various observations about these processes. Central to the concept of energy is that
processes which might at first sight appear to be very different, like those referred to in the
previous sentence, actually have a number of common features. Describing these common
features leads us to a greater understanding of what energy is.
1.1 Energy Forms and Conversions
A basic concept about energy is that while it has many forms (see Box 1.1), and can be
converted from one form to another (though some of the conversions would have no practical
value) or transformed from one grade of the same energy form to another (for example from
high temperature heat to low temperature heat), it can never be “used up”, and the actual
amount of energy stays the same. This is the basis of the First Law of Thermodynamics: in
any process involving energy,
BOX 1.1 FORMS OF ENERGY the total quantity of energy is
Kinetic energy: energy possessed by a moving object, such as conserved.
wind or water in a stream. Speed and mass of the object influence
the amount of kinetic energy. The faster the wind blows or the However, from our
more water flowing in a stream the more energy is available. observations of normal life, we
Potential energy: energy possessed by an object’s position know that in practical terms,
relative to the earth’s surface. This is stored energy which if the energy does run out. Batteries
object falls is converted into kinetic energy. For example, water in, for example, a torch
behind a dam: the higher the dam or the greater the amount of
eventually stop producing
water, the higher the potential energy.
Thermal energy (heat): A form of kinetic energy due to the electrical energy and have to
random motion of the atoms or molecules (the building blocks) of be replaced. What has actually
solids, gases or liquids. The faster the atoms or molecules move, happened is that the torch’s
the greater the thermal energy of the object, usually described as bulb has converted the
the hotter the object is. electrical energy into light – the
Chemical energy: A form of energy stored in atoms or molecules. energy form it is designed to
This energy is usually utilised by converting into heat (combustion) produce – and, to a large
or electrical energy (batteries). extent, waste heat. The original
Electrical energy: Most familiar in the form of electricity, which is
the organised flow of electrons (one of the building blocks of an
chemical energy stored in the
atom) in a material, usually a metal wire. battery has not disappeared, it
Electromagnetic energy (radiation): A form of electrical energy has just radiated into the
which all objects, in different amounts, emit or radiate. The most environment, where we can no
familiar forms are light and sound. longer make use of it. The
Mechanical energy: The energy of rotation usually associated energy may be lost to the
with a rotating shaft. system (the torch and battery),
4
, but the total amount of energy is the same before and after. It should be noted here that we
tend to focus on the energy form we want (the useful energy – the light in our example) and
regard the other as wasted (the heat), and so we neglect or overlook it. This can be an
expensive mistake, and energy conservation efforts pay a lot of attention to reducing the size of
this waste.
Energy conversions are just the ways in which we harness and utilise energy. For example, we
convert the potential energy of water stored in a dam into the mechanical energy of a turbine,
which in turn is converted into electrical energy. To pump water up from a well we do the
reverse. In everyday English we talk about “generating” and “consuming” energy, especially
when discussing electricity. These are, in fact, scientific impossibilities – what we are actually
describing is converting one form of energy to another. By generating electricity we usually
mean converting the chemical energy stored in a fuel such as coal or oil, by combustion into
heat energy, which in turn is converted into the mechanical energy of a turbine, and then into
electricity. What we in fact consume are fuels, which are forms of stored chemical energy.
1.2 Energy and Power
When utilising an energy conversion we are usually concerned with two things: the quantities of
energy involved and the rate at which energy is converted from one form to another, or
(particularly in the case of electricity) transmitted from one place to another via a medium, such
as water or high-voltage cable. The rate per second at which energy is converted or transmitted
is called the power. Thus there is a mathematical relation between the two concepts:
energy
energy = power x time or power =
time
In qualitative terms, this means that if you have a given quantity of energy, the greater the rate
at which you use it, the larger the amount of power produced. Take, for example, the chemical
energy stored in a tank of petrol, which, by a
succession of conversion processes, eventually
becomes the kinetic energy of the moving car. BOX 1.2 RELATIONSHIP BETWEEN
The more petrol allow into the engine per intake ENERGY AND POWER
stroke (by depressing the accelerator), the more At what rate per hour does a 1 kW heater
power the engine will produce and the faster the convert electrical energy into heat?
car will move. Another way to look at this is that the
more power you want from the engine, the quicker energy = power x time
you will use up the fuel. 1 kW is 1,000 watts
Since 1 watt is 1 joule per sec
In everyday English, the words “power” and 1,000 watts is 1,000 joules per sec
“energy” are often used interchangeably. If the In one hour there are 3,600 seconds
meaning is clear in the context, then a lack of
Substituting in the equation
scientific accuracy is not a problem. However, in energy = 1,000 x 3,600 joules
energy planning it is vitally important you are clear = 3,600,000 joules
which you mean. = 3.6 MJ
When describing energy conversions, the energy
Therefore a 1 kW heater converts 3.6 MJ of
resources undergoing transformation are usually electrical energy into heat per hour.
characterised in terms of their quantities, and the
conversion equipment in terms of the amount of
5
