Acknowledgement -...

Acknowledgement

This publication was funded under the National Strategy for Energy Efficiency and is a joint initiative of

Australian State and Territory Governments. The publication should be attributed to the National Centre for

Sustainability, Swinburne University of Technology.

The National Centre for Sustainability, Swinburne University of Technology would like to acknowledge the

NFEE Training Committee and industry contributions during the development of this publication.

Cover Design by Zach Bresnahan

Instructional Design and Diagrams by Justin Yong

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THE ENERGY HANDBOOK 2012

Contents

Why an Energy Handbook? .............................................................................................................. 1

Introduction .................................................................................................................................. 1

What is energy? ................................................................................................................................ 2

What are the current energy sources?............................................................................................. 2

What type of energy is available? .................................................................................................... 6

Electrical energy ........................................................................................................................... 6

Transport energy .......................................................................................................................... 8

Renewable energy ........................................................................................................................ 8

Understanding the cost of energy use ........................................................................................... 10

Energy use and greenhouse gases ............................................................................................. 12

How do you use energy? ................................................................................................................ 16

Energy conversion and transmissions ........................................................................................ 16

Calculating electrical power ................................................................................................... 20

Calculating energy .................................................................................................................. 20

Converting Wh to kWh ........................................................................................................... 21

Comparing energy consumption ............................................................................................ 21

What is energy management? ....................................................................................................... 22

Measuring energy use ................................................................................................................ 22

Supply-side management ....................................................................................................... 23

Demand-side management .................................................................................................... 23

What is energy efficiency? ............................................................................................................. 26

What is an energy rating? .......................................................................................................... 27

1 THE ENERGY HANDBOOK 2012

Why an Energy Handbook?

Introduction

This handbook aims to engage individuals in developing an understanding of energy to solve a

variety of challenges and develop opportunities related to energy conservation and efficiency at

home and in the workplace. Energy is not a new concept, but progressively more educators,

industry workers and community members are requiring an understanding of energy and a

greater level of energy literacy to engage in daily activities at home, in the wider community and

in the work place - irrespective of the industry sector. Energy literacy supports an understanding

of the role of energy in daily life and the implication for energy use in achieving a sustainable

energy future.

Energy literacy is an understanding of the essential aspects of energy, such as

energy sources and impacts,

energy conversion,

energy management,

measuring energy use and

energy efficiency.

Energy literacy is important at an individual level and for our society, given an understanding of

energy promotes:

Informed decision making;

Reduced costs;

Reduced economic, social and environmental risks and impacts;

Transition to a lower carbon economy through sustainable economic development; and

Energy independence.

An energy literate person will be able to:

Determine how energy is sourced;

Understand energy conversion and distribution;

Make informed decisions based on an understanding of energy use and impacts;

Determine how much energy is used over a determined time;

Identify ways to use energy more efficiently; and

Communicate about energy use and efficiency.


What is energy?

Energy is defined as the potential to do work or transfer heat. Kinetic energy is the energy of

motion. For example, the energy a cyclist uses to pedal a bike is turned into kinetic energy.

Potential energy is energy stored for later use. For example, water in a dam is potential energy

used to generate electricity through a hydro plant. Energy is governed by a number of laws.

Energy Laws:

Law of conservation of energy: Energy cannot be created nor destroyed. For example,

the electrical energy used to turn on a light globe doesn’t get used up, but is converted

into both light and heat energy. Only the light is useful, therefore the heat released is

‘wasted’ energy given it is not being used.

Entropy: The usefulness or quality of energy decreases as energy changes forms thus

making it less useful. For example, most of the heat energy from an electric kettle is lost

to the surrounding air and water and cannot be recaptured for any useful purpose.

This section explores some of the many forms of energy, including:

Electrical energy, the energy transmitted through electrical wires.

Electromagnetic energy which includes micro-waves, frequency signals or infra-red heat.

Thermal energy is the heat energy in the form of a solid, liquid or gas.

Mechanical energy which is the energy of movement, and can either be stored or potential energy.

Chemical energy, the energy released from stored energy in fossil fuels or biomass from both living and non-living organisms.

Nuclear energy, the energy released from the nuclei of atoms or a nuclear reaction.

Gravitational energy which includes unrestricted potential energy, like water in a dam or tidal energy.

What are the current energy sources?

We extract and harness energy from the natural world in many forms, from both renewable and

non-renewable sources. Depending on the user’s requirements, energy can be sourced from

many forms, although efficiency can be gained by selecting the most appropriate energy for a

specific task.


Image 1: Example energy sources

Non-renewable energy resources are finite; they will eventually be exhausted and not

replenished within a human timescale. Non-renewable resources are formed over millions or

billions of years, and include fossil fuels (gas, oil and coal), and nuclear fuels.

Renewable energy sources are naturally replenished in a relatively short time, which makes

them essentially inexhaustible. Renewable energy sources include the sun, wind, rain, ocean

tides, geothermal and biomass, as well as the food we grow and eat.

The Australian Department of Resources, Energy and Tourism (DRET) and the Bureau of

Resources and Energy Economics (BREE) produce an annual report ‘Energy in Australia’ to

support an understanding of our current energy usage and the direction the country is headed

to support our energy future. The current publication describes Australia’s primary energy

supply by type as shown in Figure 1: Australia’s total primary energy supply, by energy type.

Non-renewable “Black and brown coal account for the greatest share of the energy mix in

Australia, at 37 per cent, followed by petroleum products (35 per cent). The share of gas in

Australian energy consumption has increased over the past 30 years and currently stands at 23

per cent. The share of renewables in Australia’s total energy mix has remained largely constant

at around 5 per cent over the last decade.”i


Figure 1: Australia’s total primary energy supply, by energy type ii

When energy is collected, at the initial stage, it is called primary energy or the energy input into

a system. Examples of primary energy for electricity production are coal (lignite) or water for

hydro. The energy used by appliances, lighting and machinery are outputs or end-use energy.

BREE identifies and analyses trends of energy consumption, intensity and underlying factors

across six industry sectors as shown in Figure 2: Scope of the BREE Report ‘Economic Analysis of

End-use Energy Intensity in Australia’. In this report from 2012, BREE identified the following

primary energy supply, conversion and end use by sector. Energy is converted from one form to

another through conversion for end use.


Figure 2: Scope of the BREE Report ‘Economic Analysis of End-use Energy Intensity in

Australia’iii

Primary

Energy Supply

Energy

Conservation

Energy end-uses sectors

Manufacturing (10 sub sectors)

Services ( sub sectors)

Mining

Agriculture

Transport

Passenger

- Motor vehicles (cars, motorcycles, buses)

- Rail (heavy rail, light rail)

- Shipping (ferries and costal)

- Air (domestic aviation)

Freight

- Motor vehicles

- Rail

- Shipping

- Air

Residential

- Space heating

- Space cooling

- Water heating

- Cooking

- Lighting

- Appliances (10 Appliances)

Coal mine

(Coal)

Electrical

generation

Oil Well

(Crude oil)

Petroleum

refining

Natural

Gas

Primary

energy

Natural gas

processing

Final

energy

Renewable

Coke &

briquettes

manufacturing

Replicated image from BREE Economic analysis of end-use energy intensity in Australia 2012,

Commonwealth

Note: Sectors covered in this report. Production of liquefied natural gas is included in the mining sector. Consumption

of coal and liquid fuels are not covered in the residential sector


What type of energy is available?

The energy sources discussed in the previous section are generally not useful in their raw forms. Therefore, energy sources must be changed through conversion into a more useful form, for example wind is more useful when a sail is used to capture it to move a sail boat for transportation. A more complex example is when wind causes blades to move on a wind turbine to generate electricity for a range of end uses. When primary energy sources are converted, the useable energy is reduced during the conversion process.

Energy is transformed to support our homes, offices and industries for everyday living. In Australia our raw energy sources are most commonly transformed for use into electricity and transport fuels. “Australia’s [total] energy consumption is primarily composed of non-renewable energy sources (coal, oil and gas), which represent 95 per cent of total energy consumption. Renewables, mainly bioenergy (wood and wood waste, biomass and biogas), account for the remaining 5 per cent.”iv Figure 3: Total primary energy supply, by state, by energy type, 2009–10 identifies the primary energy supply by state and type for comparison across Australia.

Figure 3: Total primary energy supply, by state, by energy type, 2009–10v

State/Terr Coal

Petroleum

products Gas Renewablesa Totalb

PJ PJ PJ PJ PJ

NSW 791 613 159 63 1 648

Vic 691 422 263 44 1 406

Qld 544 477 199 104 1 301

WA 117 327 566 14 1 026

SA 78 112 133 12 348

Tas 8 38 14 31 110

NT 0 68 38 0 107

Total 2 229 2 058 1 371 286 5 945

Share of total

37.5% 34.6% 23.1% 4.8% 100.0%

Source: ABARES 2011, Australian Energy Statistics.

a State renewables data only includes hydroelectricity, solar hot water, biomass and biogas. It does not

include wind or solar PV but these are included in the total.

b Includes wind and solar PV. Totals may not add due to rounding.

Electrical energy

In Australia, electricity is supplied by both renewable and non-renewable resources. Figure 4

below shows that “most of Australia’s electricity is produced using coal, which accounted for 75

per cent of total electricity generation in 2009–10. This is because coal is a relatively low cost

energy source in Australia. It also reflects the abundance of coal reserves along the eastern

seaboard, where the majority of electricity is generated and consumed. Gas is Australia’s second

largest energy source for electricity generation, accounting for 15 per cent of electricity


generation in 2009–10. Renewable energy sources, mainly hydroelectricity, wind and bioenergy,

accounted for around 8 per cent of the electricity generation mix in 2009–10.”vi

Figure 4: Australia’s electricity generation, by energy source, 2009–10avii

a Other includes oil, bioenergy and solar PV. Source: ABARES 2011, Australian Energy Statistics, Table O.

During the production of electricity from coal (primary energy), a chemical energy is produced

releasing heat, this is called thermal energy. This heat or thermal energy generates steam which

drives a turbine, and in turn creates mechanical energy, which turns a generator, thus creating

electricity or electrical energy (end use energy).

At each of these conversions useful energy is lost, but not destroyed, to the environment.. An

overview of the coal electricity generation process is shown in Image 3.

Image 3: Overview of coal electricity generation


Transport energy

A fuel is generally a source of energy burned through a combustion process to produce heat,

mainly through use of refined petroleum products, although ethanol and biofuels are also

available in Australia. Energy in Australia 2012 states that, “The transport sector is the largest

end user of energy in Australia. More than 38 per cent of Australia’s final energy use is employed

in moving people and goods across the country. As a large continent characterised by major

population centres located along its coastline, Australia requires goods to be transported long

distances. The transportation sector is the largest consumer of liquid fuels (including LPG and

refined products), accounting for 73 per cent of Australia’s final use of liquid fuels… Within the

transport sector, road transport is the largest user of final energy, accounting for 76 per cent of

the sector’s liquid fuel consumption.”viii

Renewable energy

Australia’s current renewable solar energy market and incentives are described in BREE’s Energy

in Australia 2012 report as ‘Clean Energy’. “Currently, around 67 per cent of Australia’s

renewable energy is comprised of biomass... Hydro power for electricity generation makes up 16

per cent of renewables consumption, with the remaining 17 per cent comprising biofuels, wind

and solar energy consumption.”ix

BREE describes the constraint of current clean energy technologies, being:

higher transformation costs relative to other energy technologies

often long distances from existing transmission and distribution infrastructure and markets; and

current technologies used to utilise them are often immature.


The BREE report explains:

“despite these constraints, clean energy technologies will play an important role in moving to a low

emissions future while meeting Australia’s continued demand for energy….Clean energy sources

currently used in Australia include hydro, biomass, biogas, wind energy, and solar energy. There is also

potential for a number of emerging clean energy technologies that are yet to be commercially

deployed, including large scale solar energy plants, geothermal generation technologies, ocean energy

technologies, and carbon capture and storage (CCS) to reduce emissions from coal, oil and gas use.

The distribution of clean energy production facilities in Australia reflects the climatic characteristics of

different regions. Hydroelectricity capacity in Australia is located mostly in New South Wales,

Tasmania, Queensland and Victoria; while wind farms are most abundant in South Australia and

Victoria. Almost all bagasse-powered energy facilities are located in Queensland where sugarcane

production is located. In contrast, there is a more even distribution of biogas-powered facilities across

Australia, as these facilities are mostly based on gas generated from landfill and sewerage.”x

An overview of the mix and location of clean energy across Australia is shown in Figure 5.

Figure 5: Renewable energy generators operating plants with capacity of more than 30

kilowattsxi

Source: Geoscience Australia.


The Australian Government is encouraging the uptake of clean energy technologies through the

following incentives and measures:

Expansion of the Renewable Energy Target (RET) (Jan 2010) will ensure that 45,000 gigawatt hours of Australia’s electricity supply will be sourced from renewable energy by 2020

Solar Credits Scheme

The Clean Energy Future Plan (Nov 2011) targets the reduction of Australia’s carbon emissions to 5 percent below 2000 levels by 2020 and 80 per cent below 2000 levels by 2050

Introduction of a carbon price and package of complementary measures (Jul 2012)

Establishment of the Australian Renewable Energy Agency (ARENA) (Jul 2012) which will support funding and knowledge sharing for innovation related to renewable energy technologies.xii

Australia’s future renewable energy market has been researched by the University of Melbourne’s Energy Research Institute and reported in the ‘Australian Sustainable Energy: Zero Carbon Australia Stationary Energy Plan’. The Zero Carbon Australia 2020 Plan (ZCA2020 Plan) is a ten year plan outlining the current opportunities for Australia to enter a 100% renewable energy market consisting of the following technologies.

“Technologies that were chosen for the ZCA2020 Plan:

can supply the required 325 TWh/yr with the flexibility to meet seasonal and daily variation in demand;

are commercially available today;

produce zero greenhouse emissions after construction;

The chosen renewable energy technologies are a mix of wind turbines, concentrating solar

thermal with storage, small-scale solar, and contingency capacity from biomass and existing

hydroelectricity”.xiii

Understanding the cost of energy use

The section explores the cost of energy use associated with the natural environment, our society

(local and global communities) and our economy. Our society is dependent on energy and rising

electricity and fuel prices are increasing costs across our economy. BREE states that “the price of

electricity is determined by a number of factors such as transmission and distribution network

costs, the wholesale electricity price faced by retailers, and government policies. Recently, a

major driver of rising retail electricity prices has been the significant investment in new and

ageing transmission and distribution infrastructure required to support increasing demand for

electricity. The Australian Energy Market Commission estimates that transmission and

distribution network costs represented between 44 to 53 per cent of the retail electricity price

faced by households in 2009–10, with wholesale electricity prices representing a further 35 to 40

per cent.”xiv

The following table explores the cost of energy use on our environment, society and economy.

These costs vary dependant on the energy source as briefly described in Figure 6.


Figure 6: Energy sources and associated impacts

Type of energy

Opportunities Impacts

Hydro (Renewable)

Electricity

Thermal storage

Potential disturbance of land, environment and habitat.

Potential benefit to community and individual health and liveability, energy independence, increases in jobs, reduced operational costs.

Flexibility of system for quick response time to support peaks in electricity demand

Wind (Renewable)

Electricity

Thermal storage

Aesthetics, potential noise and land and habitat disturbance.

Potential benefit to community and individual health and liveability.

Energy independence, increases in jobs, reduced operational and infrastructure investment costs.

Bioenergy (Renewable)

Biofuels for transport

Biomass electricity

Potential air and land pollution due to burning of biomass, deforestation, environmental and habitat disturbance/reduction.


Energy independence, increases in jobs, reduced operational costs.

Solar Photovoltaic (Renewable)

Electricity Aesthetics and potential for technology waste disposal / recovery.



Solar Thermal (Renewable)

Thermal storage

Aesthetics and potential land disturbance/reduction.



Tidal and wave energy (Renewable)

Electricity Aesthetics, and potential land and habitat disturbance.

Potential benefit to community and individual health and liveability


Heat from the earth (Non-renewable*)

Thermal energy

Electricity * Over a long period (thousands of years), geothermal energy could be depleted.

Potential disturbance or pollution to local soil, ground water.

Potential benefit to community and individual health and liveability


Coal Australia has large Pollution and disturbance to the local and


Gas Oil (Non-renewable)

coal and gas reserves but finite resources (fossil fuels)

Fuel for transport

Electricity

broader communities, including land, water, habitat, air, greenhouse gases, and noise as a result of extraction, spills, leakage, use and transport).

Elimination of resources.

Potential health related issues to both workers and the local community.

Uranium (Non-renewable)

Australia has large reserves of Uranium but finite resources

Nuclear Energy

Electricity

Transport

High pollution potential to all living things.

Related impacts (social, political, economic and health related) to the local and broader communities

Elimination of resources.

Pollution and disturbance to the local and broader communities, including land, water, habitat, air, greenhouse gases, and noise as a result of extraction, spills, leakage, use and transport).

Energy use and greenhouse gases

Greenhouse gases (GHG) naturally occur in the earth’s atmosphere. The earth’s atmosphere

requires a balance of heat absorption from the sun and heat released back into outer space as

part of the Earth’s energy balance and to maintain life as we know it as depicted in Image 4.

Image 4: Overview of the greenhouse effect


Greenhouse gases include naturally derived gases, being water vapour and ozone which have

the ability to trap heat. The burning of fossil fuels and other human activity has led to increases

in other greenhouse gases, such as carbon dioxide, methane, nitrous oxide, chlorofluorocarbons

(CFCs) and some other gases contributing to the enhanced greenhouse effect in the atmosphere.

Human induced greenhouse gases have progressively increased in the earth’s atmosphere, as

shown in Image 5, most often through burning of wood, burning of coal for electricity, natural

gas, transport fuels, livestock (belches and wind), the breakdown of landfill waste (methane),

refrigerant use (some gases used for heating and cooling), cement production, agriculture

(fertilizer), industrial processes (nylon for fabrics), etc.

Image 5: Overview of greenhouse gases

As a result of the greenhouse effect, global temperatures of the air and water have risen. When

ocean temperatures rise, water current cycles can change which affects the weather systems.

These changes to weather patterns lead to changes in climate and can cause other flow-on

An animation and interviews with experts can be viewed online through the

ABC Science production series, ‘Crude: the incredible journey of oil’ xiv

Select Crude part 1.

The series is a visual journey of the formation of fossil fuels from the age of the dinosaurs

offering insight into the current release of greenhouse gases related to using energy stored

below the earth’s surface.

http://www.abc.net.au/science/crude/


effects across landscapes and waterways. The impacts of climate change on agricultural systems,

businesses and communities include temperature and rainfall pattern changes, increased floods,

droughts and potential water shortages, in addition to rising sea levels and other natural

disasters.xv

As a result of the type of energy used to supply our needs, Australia’s greenhouse gas (GhG)

emissions are high in comparison to other countries. As shown in Figures 7 and 8, Australia has

the highest emissions per person per year due to our energy sources.

Figure 7: Per capita emissions due to energy use (2005) xvi

Figure 8: Australian Energy Use by type compared to other countriesxvii

Australia’s high GhG emissions result from high consumption of coal, both black and brown, as

the primary energy source to generate electricity and transport fuel consumption, mainly from

petroleum, as shown in Figure 9. By shifting our primary energy sources to cleaner energy, we

can significantly reduce our emissions in the future.


Figure 9: Australia’s energy consumption, by energy typexviii

Energy Type 2005-06 2006-07 2007-08 2008-09 2009-10

PJ PJ PJ PJ PJ

Consumption of fuels

8 084 8 264 8 367 8 366 8 353

Black coal 1 639 1 686 1 655 1 527 1 488

Brown coal/lignite

705 611 630 751 742

Coke 76 77 78 63 73

Coal by-products

81 78 80 55 66

Liquid biofuels 1 2 5 7 10

Wood, woodwaste

90 93 108 103 103

Bagasse 109 111 112 103 88

Refinery input 1 407 1 503 1 462 1 480 1 439

Petroleum products

1 968 2 000 2 062 2 072 2 090

Natural gas 1 108 1 187 1 237 1 323 1 382

Town gas 7 7 4 3 0

Solar energy 2 6 7 8 10

Total electricity

891 904 929 871 860

of which Hydro 58 52 43 40 45

wind 6 9 11 14 17

solar 0.4 0.4 0.4 0.6 1.0

Production of derived fuels

2 460 2 574 2 605 2 487 2 409

Coke 98 98 98 69 76

Coal by-products

81 81 82 54 65

Petroleum productsa

1 429 1 534 1 557 1 544 1 471

Town gas 5 5 4 3 0

Thermal electricity

847 857 863 817 797

Total energy

consumptionb 5 625 5 690 5 763 5 879 5 945

Source: ABARES 2011, Australian Energy Statistics, Table C. a Production may exceed refinery input as some petroleum

products are produced from other petroleum products. b Total energy consumption is the total quantity (in energy

units) of primary and derived fuels consumed less the quantity of derived fuels produced. Totals may not add due to

rounding.


How do you use energy?

Energy is mainly used for electricity generation and transportation as shown in the BREE Figure

10: Australia’s net energy consumption by sector. To make significant reductions in our energy

use, we need to better understand our energy use, and its impacts. By identifying opportunities

to reduce and conserve energy, we can then minimise the energy consumed to perform work

and daily living tasks. This will be discussed further in the section on energy demand.

Figure 10: Australia’s total energy consumption by economic sectorxix

Sector 1974-75 1979-80 1989-90 1999-00 2009-10

PJ PJ PJ PJ PJ

Agriculture 39 47 55 72 96

Mining 65 81 160 273 509

Manufacturing 928 965 1 067 1 192 1 261

Electricity generation

540 743 1 066 1 427 1 793

Construction 29 38 41 29 25

Transport 701 825 1 012 1 267 1 447

Commercial a 87 104 151 219 295

Residential 246 262 322 392 440

Other b 59 66 71 102 78

Total 2 695 3 131 3 946 4 971 5 945

Totals may not add due to rounding. a Includes ANZSIC Divisions F, G, H, J, K, L, M, N, O, P, Q and the water, sewerage

and drainage industries. b Includes consumption of lubricants and greases, bitumen and solvents, as well as energy

consumption in the gas production and distribution industries and statistical discrepancies.

Source: ABARES 2011, Australian Energy Statistics.

Energy conversion and transmissions

Energy Conversion is defined by BREE as,

“The process of transforming one form of energy into another (derived) form before

final end use. Energy used in conversion is the energy content of fuels consumed as

well as transformed by energy producing industries. Examples are gas and liquefied

petroleum gas used in town gas manufacturing, all hydrocarbons used as feedstock in

oil refineries, and all fuels (including electricity) used in power stations—therefore,

energy used in conversion also includes energy lost in the production, conversion and

transport of fuels (such as energy lost in coke production) plus net energy consumed

by pumped storage after allowance for the energy produced.”xx


When energy is converted from one form to another, there are ‘losses’ related to conversion.

This has implications for the energy efficiency of an overall system. For example, during the

process of coal being burned to produce electricity, the main energy conversions/transfers are:

Burning coal (chemical) to produce heat (thermal);

Heat transfer from flames to boil water and make steam;

Steam (thermal) turns turbines (mechanical);

Turbines transfer energy to electrical generator’s shaft;

Generator shaft rotation (mechanical) produces electricity in the coils (electrical).

In any energy system, the energy available to do useful work is reduced by losses when it is

transformed form one form to another. For example, less than half of the energy stored in a

piece of coal becomes electricity, the rest is lost as heat, light & sound into the environment. The

electrical voltage transforms as the energy enters the grid and leaves the grid and there are

losses as it travels along the grid and as electricity is used in end-use devices. Overall, the end-

use energy only provides a small percentage of the primary energy used to create it, sometimes

referred to as ‘useful energy’. The energy that is ‘lost’ is not truly lost – it still exists, but it is in a

form which we cannot use.

Image 6: Conversion and transmission loses

A detailed example of transport energy includes the petrol or fuel used to power a car, which is a

high quality energy source. In other words, it concentrates a large amount of energy into a

relatively small mass. That energy is easily accessed by burning during combustion. In the

process, around 70% of the energy is converted to other forms which are of no use in making

the engine work.


These forms include:

Sound (mechanical energy);

Friction (thermal energy);

Air turbulence (mechanical energy); and

Heat from the exhaust in the form of hot air (thermal energy).

None of the above forms of energy help to make the car move forward (the original intention)

and are therefore ‘lost’ energy which cannot easily be harnessed or made useful. In other words,

very little of the energy actually transports the person, most has been used to power the car.


How do we measure energy and power?

In order to understand units of energy to measure and compare energy efficiency, the standard

metric measurements must be understood. The scientific unit of work is a joule (J) (named after

James Prescott Joule) which is work from a force of one newton acting over the distance of one

metre. A basic unit of energy is a joule (J), but more often energy is measured in much larger

quantities such as kilojoules (1,000 joules), megajoules (1,000,000 joules) and gigajoules

(1,000,000,000 joules).

Electrical energy used for power, which we call electricity, is measured in watts(one joule per

second). Although, electrical energy is frequently measured as a kilo watt-hour (kWh), being

1,000 watts consumed over one hour. Other common measurements are summarised in Figure

11.

Figure 11: Common units of measurement & symbols

Energy Unit Symbol Example Type of Energy Measured

Calorie CAL Chemical Human energy

Joule J Basic Basic Energy

Kilojoule kJ Thermal Gas

Megajoule MJ Thermal Gas

Gigajoule GJ Thermal Gas

British thermal unit Btu Thermal Heating and Cooling

Watt W Electrical Electricity

Watt-hour Wh Electrical Electricity

Kilowatt-hour kWh Electrical Electricity

Amperes (Amps) A Electrical Current or flow rate

Volts V Electrical Force or pressure driving the current

Direct Current DC Electrical Unidirectional flow

Alternating Current AC Electrical Reversing flow

Quantity measurement Symbol Example

Kilo K 10³ (thousand) 1 kWh or kilo watt hour = (1000 watts)

Mega M 10⁶ (million) 1 MJ or megajoule = 1,000,000 joules

Giga G 10⁹ (1000 million) 1 GJ or gigajoule = 1,000,000,000 joules

Litre L Fuel Transport

Gram G Volume Liquid

Tonne T Gas/volume Greenhouse gases / oil

Metre M distance Length

Cubic metre m³ Volume Liquid

Barrel Bbl Volume Oil

Time Measurement Symbol Example

Hour H Per hour kWh

Per annum Pa Per annum 500 MJ pa


Calculating energy use can be accomplished by determining the power required by a device and

the time the device is in use.

Calculating electrical power

Electrical power is the power required by an appliance or machine, typically stated on a data

plate. The data plate states the power rating in volts and amps or the watts required to use the

appliance or machinery as shown in Image 7: Data plate example.

Image 7: Data plate example

To calculate the power in watts (W), the voltage (V) is multiplied by the current amps (A).

Example: The laptop data plate in Image 7 requires 19 volts (V) and 3.42 amps (A), calculated as:

19V x 3.42A = 65W

For a comparison, a blender which is rated at 240V at 5.42A, is calculated as:

(power) 240V x 5.42A = 1,300W

Calculating energy

Energy is the actual usage of electrical energy over time, most often reflected on a utility

statement from the electricity company.


Energy is calculated in watt-hours (Wh), by multiplying power (W) by time in hours (h).

Example: The laptop discussed previously required 65W of electrical energy.

If it is used over 3 hours, the energy required is calculated as:

65W x 3h = 195 Wh

For comparison, a blender is rated at 1,300W. How much energy is used by the blender in 2 hours?

1,300 x 2 = 2,600 Wh

Converting Wh to kWh

A kilowatt hour (kWh) is when 1000 watts (1 kW) are used during one hour. Therefore, to

determine the energy in kWh for an appliance or device, the watts are multiplied by the time

used and then divided by 1000 .

Example: The laptop requires 65W over 3 hours calculated as 195 Wh.

To calculate the kWh, divide the total Wh by 1000:

195/1000 = 0.195 kWh

For comparison, the blender required 1,300 W over 2 hours calculated 2,600 Wh or 2.6 kWh

Comparing energy consumption

To compare energy, the same unit of measurement is required. On a utility bill for natural gas

usage it is often measured in joules (J) or mega-joules (MJ), although electricity is measured in

kilo-watt hours (kWh). These units must be converted into joules or mega-joules for comparison.

Thermal energy is sometimes measured using British Thermal Units (Btu), MJ (mega joules)

and/or kWh are most often used to measure heating and cooling systems.

A kilo-watt hour can be converted to joules given there are 1,000 watts in a kilo-watt over 1 hour

(60 minutes including 60 seconds in each minute). Therefore, to determine the total seconds in

one hour, 60 seconds (s) is multiplied by 60 minutes (m) or 60s x 60m = 3600 seconds.

Example: 1kWh = 1000w x 3600s

= 3,600,000 J

To determine MJ = 3,600,000 (J) / 1,000,000 (M)

= 3.6 MJ

Energy = power x time

For example, electricity is connected to a house providing a power supply, but the energy is

not used until a service, e.g. a light is turned on for a period of time. If two lights that are

exactly the same are turned on the power, rate of consumption, is doubled.


What is energy management?

The demand for electrical energy is growing rapidly creating issues related to:

overall electricity demand;

peak demand, the period of highest consumer electrical demand;

electricity generation capacity and availability;

electrical infrastructure capacity and availability;

massive capital investment required and the accompanying consumer electricity price

increases;

environmental and social impacts.

In this section some approaches available to manage the electricity demand are discussed.

Measuring energy use

The best method to manage energy use is by first determining amount of energy used through

an energy audit.

A desktop audit, Level 1, can be completed by collecting and reviewing monthly, quarterly or

annual energy statements or contacting your energy provider to request a copy. Level 2 may

include a walkthrough audit of a designated area, such as a home, small business, large

commercial business or industrial plant to review data plates. During a walk through audit the

following should be determined:

1. Identify the number and type of appliances / devices requiring energy;

2. The amount of energy required per appliance / device based on the power rating from

the data plate

3. The amount each is used over a specified timeframe (minutes, hours, days, per annum,

etc.).

Once energy use and demand is determined, the information is analysed against conservation

and energy efficiency opportunities. To engage further in this process, a second complimentary

educational resource titled ‘Energy Efficiency Supplement’ is available to support the audit

analysis process.

The Australian / New Zealand Standard for Energy Audits is ANZS 3598:2000, defined in 3

levels:

Level 1 – Overview: Identifies energy consumption across a site to develop an initial

benchmark, typically in the form of a desktop audit (accuracy within +/-40%);

Level 2 – Energy Use Audit: Identifies energy sources, amount used and where it is

used to determine areas of potential savings (accuracy within +/-20%); and

Level 3 – Audit Analysis: Detailed analysis of energy use to determine savings

potential including the costs and benefits of implementing the recommended

savings (accuracy within +10% for costs and -10% for benefits).


Supply-side management

Energy is supplied to consumers from a source controlled by centralised power generators and

distributors, mainly non-renewable coal and gas. Supply-side management (SSM) is the control

of energy delivery at the suppliers’ side (i.e. upstream of the meter in the case of electricity

supply). Centralised energy production can be sourced from renewable energy on a large scale,

such as wind or solar farms. Energy suppliers must:

Match supply capability to long-term demand.

Ensure instantaneous capacity is always larger than peak demand.

Match energy sources to efficiently meet the current demand.

Improve the efficiency of generation and distribution.

In an effort to increase the amount of renewable energy used to produce electricity, incentives

have been introduced. The energy retail market supports the Mandatory Renewable Energy

Target (MRET) through Renewable Energy Certificates (REC). The MRET requires that a given

percentage (currently 20% by 2020) of electricity will be sourced from renewable energy.

Additional costs from energy suppliers are passed on to consumers due to a number of factors.

The current electricity system must respond to a growing demand for electricity due to

increased use and a growing population. The current energy generation and distribution system

requires up to date infrastructure in place of the current aging and out-dated system. New

renewable energy sources require new infrastructure to be developed. Extreme weather and

weather related events such as bushfires, drought and flooding can also impact on energy supply

and distribution by damaging the electricity transmission lines. These extreme weather events

are likely to increase in intensity and frequency as climate change progresses.

Demand-side management

End users have an opportunity to manage the demand for electrical energy, firstly through

conservation. When managing energy from the demand side, electrical energy efficiency will be

maximised due to greater reductions at the primary energy source. These reductions are also

linked to savings during transmission from the source (primary energy) to the end use point.

The following describes demand side management (DSM) opportunities to minimise energy

consumption on the consumers’ side, broadly described as:

1. Energy conservation/efficiency programs for machines/appliances/ devices – designed

to reduce the amount of something being used or overall consumption. Examples:

minimising energy demand by turning equipment off when not in use, setting or

selecting the energy efficiency option for automatic shut down when not in use after a

specified time frame, de-lamping or installing energy efficient lights or automation

systems to turn lights off after a specified period of time, installing energy efficient

kitchen/office/media appliances, even improving insulation or installing energy efficient

windows to reduce heating and cooling needs.

2. Load or demand management programs – designed to reduce peak demand by shifting

activities to off-peak hours. Examples: load control is determined by identifying the


machines or appliances which have the highest energy demand and shifting the

associated activities to off peak times.

3. Distributed power generation – power produced at or near the point of use. Examples:

solar photovoltaic (PV) panels can often harness more energy than required at the point

of use or may harness energy at times when the energy is not used on site. This energy

can be re-distributed into the electrical distribution system to sell for use to other

customers.

4. Fuel substitution programs – switching to a more efficient or renewable fuel for a

particular application or system. For example: switching from coal to natural gas to

generate heat or electricity. Alternatively, solar water heating systems which can

provide a significant percentage of the requirements for hot water heating in place of or

assisted by an electric or gas boosted system.

Demand side incentives include rebates or certificate schemes to encouraging large scale

changes given that consumer cost savings may be relatively small when energy prices are low.

Solar PV systems installed and connected through two-way electricity meters are an example of

a renewable ‘distributed energy system’. The energy is generated on-site in small amounts

across a large area as opposed to a traditional system from a distant source at a centralised

power station. Consumers generate, own and use the energy at the local level, therefore

increasing the efficiency of the system by reducing the length the energy has to be transmitted

from the primary source to the end use point.

However, the electricity grid was designed for centralised generation and distribution and is

currently not well suited for distributed generation. Balanced control of the grid, to match

demand with supply to prevent blackouts, depends on traditional centralised generation

systems. Although, distributed energy generation supports:

Supply efficiency - fewer transmission losses occur when the energy source is local.

Supply security – although generation from some sources is dependent on weather etc.,

there is no single point of failure on distributed systems.

Supply infrastructure – costs and environmental impacts are reduced as a result of

reduced need for power lines and pylons.

Two way meters are being installed across Australia are increasing the complexity of our energy

systems, meaning they are no longer a one way system as shown in Image 8: Future electricity

distribution systems.


Image 8: Future electricity distribution systems


What is energy efficiency?

Although our actions and systems impact on other systems, compromises and trade-offs must

be understood to determine the most appropriate options based on end use requirements.

Different types of energy are more efficient than others based on a number of factors.

Generally, energy efficiency is based on an equation where the amount of energy input is

compared to the amount of energy output. In an effort to increase efficiency the aim is to either:

1. Do less - conservation

2. Do the same with less - use less energy while achieving the same level of output or

3. Do more with less - use the same amount of input while increasing the level of output

4. Do less with even less – eliminate all unnecessary work and determine the most efficient

process to carry out the remainder of the work

In an effort to maximise electrical energy efficiency, two things need to be supported:

Firstly, the number of conversions across the system transferring the energy to the end

user must be minimised to prevent ‘loss’ of useful energy and

Secondly, the conversion efficiency process must be maximised

Energy losses also occur at the end user stage if the appliance, lighting or machinery is not

performing to maximum efficiency increasing energy losses.

“There has been a long-term decline in the energy intensity (energy consumption per unit of gross

domestic product) of the Australian economy. This trend can be attributed to two main factors. First,

energy efficiency improvements have been achieved through both technological change and fuel

switching. Government policies at both the national and state/territory level have contributed to the

implementation of new technologies that improve energy efficiency. Second, rapid growth has

occurred in less energy-intensive sectors, such as the commercial and services sector, relative to the

more moderate growth of the energy-intensive manufacturing sector. Trends in energy intensity are

not uniform across Australia.”xxi

An example of end use efficiency through product selection is replacing a standard incandescent

100 watt light bulb with a more energy efficient 20 watt light bulb. By selecting the energy

efficiency light bulb the primary energy being sourced is not only reduced, but the heat loss at

the end use has been minimised. Image 9 shows a comparison of an incandescent light bulb and

an energy efficient compact fluorescent at the primary and end-use points.


Image 9: Energy efficiency of an incandescent vs. compact fluorescent

What is an energy rating?

Efficiency can be gained by selecting the most appropriate energy for a specific task. As well as

the (in)efficiencies within a system, there are wider pros and cons for the choice of technology

applied to provide a service.

Energy labels, as shown in Figure 12, can assist consumers in making purchase choices. Products

are rated using a star system. The number of stars is based on the energy requirements of a

particular appliance or machine. The number of stars allow for a quick comparison from one

product to another of the same type without a need to calculate the energy inputs and outputs

based on the appliance’s data plate. The more efficient the appliance, the more stars it is given.

For example, a three star appliance would require less energy, therefore, cost less to run

compared to the same type of appliance that only has one star.


Figure 12: Example of an energy label for a heating and cooling systemxxii

Energy Efficiency can be explored further in the second part of this series titled, Energy

Efficiency Supplement 2012.

http://www.swinburne.edu.au/ncs/energy_handbook/the_energy_efficiency_supplement.pdf

http://www.swinburne.edu.au/ncs/energy_handbook/the_energy_efficiency_supplement.pdf


REFERENCES

i BREE, 2012, Energy in Australia 2012, Canberra, February, Commonwealth of Australia http://bree.gov.au/publications/energy/index.html, p. 21, viewed June 2012 ii BREE, 2012, Energy in Australia 2012, Canberra, February, Commonwealth of Australia

http://bree.gov.au/publications/energy/index.html, p.24 viewed June 2012 iii BREE, 2012, Che, N. and Pham, P., Economic analysis of end-use energy intensity in Australia, Canberra,

May, http://bree.gov.au/publications/energy/index.html, p.2 viewed June 2012 iv BREE, 2012, Energy in Australia 2012, Canberra, February, Commonwealth of Australia

http://bree.gov.au/publications/energy/index.html, p.19 viewed June 2012 v BREE, 2012, Energy in Australia 2012, Canberra, February, Commonwealth of Australia

http://bree.gov.au/publications/energy/index.html, p.22 viewed June 2012 vi BREE, 2012, Energy in Australia 2012, Canberra, February, Commonwealth of Australia

http://bree.gov.au/publications/energy/index.html, p. 33 viewed June 2012 vii

BREE, 2012, Energy in Australia 2012, Canberra, February, Commonwealth of Australia http://bree.gov.au/publications/energy/index.html, p.33 viewed June 2012 viii

BREE, 2012, Energy in Australia 2012, Canberra, February, Commonwealth of Australia http://bree.gov.au/publications/energy/index.html, p. 99viewed June 2012 ix BREE, 2012, Energy in Australia 2012, Canberra, February, Commonwealth of Australia

http://bree.gov.au/publications/energy/index.html, p. 22, viewed June 2012 x BREE, 2012, Energy in Australia 2012, Canberra, February, Commonwealth of Australia

http://bree.gov.au/publications/energy/index.html, p. 47 & 52, viewed June 2012 xi BREE, 2012, Energy in Australia 2012, Canberra, February, Commonwealth of Australia

http://bree.gov.au/publications/energy/index.html, p. 53, viewed June 2012 xii

BREE, 2012, Energy in Australia 2012, Canberra, February, Commonwealth of Australia http://bree.gov.au/publications/energy/index.html, p. 54-55, viewed June 2012 xiii

ZCA2020 Stationary Energy Plan Synopsis, University of Melbourne’s Energy Research Institute, p.5 http://media.beyondzeroemissions.org/ZCA2020_Stationary_Energy_Synopsis_v1.pdf, viewed July 2012 xiv

BREE, 2012, Energy in Australia 2012, Canberra, February, Commonwealth of Australia http://bree.gov.au/publications/energy/index.html, p. 40, viewed June 2012 xv

ABC Science, 2007, Crude- the incredible journey of oil, ABC http://www.abc.net.au/science/crude/ , viewed July 2012 xvi

The Garnaut Climate Change Review, Chap 7 Australia’s Emissions in a Global Context, Commonwealth of Australia 2010 http://www.garnautreview.org.au/chp7.htm xvii

The Garnaut Climate Change Review, Chap 7 Australia’s Emissions in a Global Context, Commonwealth of Australia 2010 http://www.garnautreview.org.au/chp7.htm xviii

BREE, 2012, Energy in Australia 2012, Canberra, February, Commonwealth of Australia http://bree.gov.au/publications/energy/index.html, p. 23, viewed June 2012 xix

BREE, 2012, Energy in Australia 2012, Canberra, February, Commonwealth of Australia http://bree.gov.au/publications/energy/index.html, p. 28, viewed June 2012 xx

BREE, 2012, Energy in Australia 2012, Canberra, February, Commonwealth of Australia http://bree.gov.au/publications/energy/index.html, p. xi, viewed June 2012 xxi

BREE, 2012, Energy in Australia 2012, Canberra, February, Commonwealth of Australia http://bree.gov.au/publications/energy/index.html, p. 20, viewed June 2012 xxii

Supplied by Sustainability Victoria 2012

http://bree.gov.au/publications/energy/index.html












http://media.beyondzeroemissions.org/ZCA2020_Stationary_Energy_Synopsis_v1.pdf


http://www.abc.net.au/science/crude/

http://www.garnautreview.org.au/chp7.htm

http://www.garnautreview.org.au/chp7.htm





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