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The use of energy in the home is the largest source of

4 .0 E n e r g y u s e i n t r o d u c t i o n
greenhouse gas emissions from Australian households. 14%Heating and Cooling
The average household’s energy use is responsible for
28% Water heating
about eight tonnes of carbon dioxide (CO2), the main
greenhouse gas, per year. Many of these emissions can be 19% Other appliances
abated through more efficient use of energy in our homes.
9% Lighting
6% Cooking
17% Refrigeration
7% Standby

Greenhouse gases from home energy use (based on AGO 1999).

4% Standby energy use

9% Refrigeration
12% Other electrical appliances

5% Lighting

39% Space heating/cooling

27% Water heating

The other main contributors to household greenhouse 4% Cooking

emissions are transport and waste.
Choosing the most appropriate energy source can Energy use in the average Australian home (based on AGO 1999).
significantly reduce your energy bills and improve the
environmental performance of your home. A choice of
energy sources is available to new home buyers, existing Space heating and cooling and water heating account for
owners and tenants. nearly 70 percent of household energy use.

Conventional electricity from the supply grid currently The energy use and greenhouse gas charts shown above
produces the largest amount of CO2 of any energy source illustrate the different rates at which gas and electricity
per unit of energy used, except in Tasmania where hydro consumption produce greenhouse gases. The higher the
electric power is used. use of electricity, the more greenhouse gas emissions are
produced.
Water heating, refrigeration and space heating and cooling
Renewable energy sources produce produce the most greenhouse gases. Other major sources
no greenhouse gases in operation are cooking, lighting and stand-by energy use.
and reduce or eliminate the need Look for ways to reduce consumption through efficient use.
for additional coal fired power Monitor your energy bills and check for unexpected
stations and large hydro-electric increases and how they can be reduced through more
efficient energy use. A list of contacts for information on
dams. using energy efficiently can be found at the end of this sheet.

Natural gas produces only about one third the greenhouse

emissions compared to conventional electricity.
Minimising demand for energy through conservation and
efficiency is the most cost effective means of reducing
operational and environmental costs for all home owners
and tenants.
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Green Power is often the easiest and

4 .0 E n e r g y u s e i n t r o d u c t i o n

ENERGY SOURCES
least expensive way to purchase
electricity from renewable sources.
The main sources of household energy are electricity,
Most electricity retailers have an
natural gas and wood. A small number of homes use LPG,
accredited Green Power option for a
coal, coke or heating oil.
slightly higher unit charge. By choosing Green Power,
Energy can come from either renewable or non-renewable you are supporting the expansion of renewable
sources. Renewable sources such as solar, wind and systems. Contact your electricity supplier or visit
hydro-power are naturally replenished and produce very www.greenpower.com.au.
few greenhouse gas emissions when operating. Non-
Households can generate their own electricity from
renewable energy comes from diminishing stocks of fossil
renewable sources. These can be either grid interactive or
fuels and can produce large amounts of greenhouse gases.
self sufficient, stand alone systems. [See: Renewable
Most electricity comes from coal fired power stations that Electricity Overview]
release high levels of CO2 and other pollutants into the
Renewable electricity systems are initially expensive to
environment. Losses in the transmission system from the
install but have low operating costs and minimum
power station to your home also create inefficiency.
environmental impact. Government rebates are available
Using natural gas results in only about one third of the to offset the initial costs.
greenhouse emissions compared to grid electricity.
Electricity consumption can be reduced through energy
Hydro electricity generated in Tasmania directly produces efficiency and fuel switching. As energy costs rise and
almost no greenhouse gas. However, the construction of awareness of environmental issues increases, the value of
new large-scale hydro-electric dams can be sources of properties with energy efficient features and renewable
large amounts of greenhouse gas and may have other energy supply is expected to rise.
adverse environmental effects.
GAS
Natural gas is less expensive to use than electricity and
produces fewer greenhouse emissions. However, gas is
also a non-renewable fuel. It is largely used for water
heating, room heating and cooking. It can, however, also
be used for clothes drying, as a vehicle fuel and even
for refrigeration.
Arthur Mostead Photography

Courtesy of AGL Pty Ltd

ELECTRICITY
Electricity is the most widely available energy source and
the only one able to run the full range of household
appliances. But on the mainland it is the most greenhouse
intensive energy source. It is also usually the most
expensive per unit of energy used.
Natural gas is not available everywhere but liquefied
petroleum gas (LPG) can be used instead. It produces
similar greenhouse emissions to natural gas but must be
Consumers of grid electricity can transported by tanker or in cylinders, which adds to its
offset its environmental impact by financial and environmental cost. LPG costs more than
twice as much to use as natural gas.
purchasing “Green Power”.
Adequate room ventilation is required when using unflued
gas appliances. [See: Indoor Air Quality]
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WOOD HOT WATER
Wood can be a renewable energy source if it comes from Choose the most efficient hot water service and the best
sustainably managed forests. Its use should make no net energy source to meet your needs. Solar, gas and electric
contribution to greenhouse gases if trees are planted to heat pump systems produce far fewer greenhouse
replace those used, but fossil fuels are usually used in emissions than conventional electric storage systems. Gas
collection and transportation. boosted solar is the most greenhouse efficient form of
water heating.
In many non-urban areas, wood is widely used for heating,
cooking and heating water. Wood is generally not a Gas heaters have star ratings accredited by the Australian
desirable energy source for urban areas due to local air Gas Association (AGA) to help you choose the most
pollution problems. Some efficient, low pollution stoves efficient model. The star rating scheme also covers gas
ducted and space heaters.
are available but are more expensive.
A list of star ratings is available on the AGA’s website at
OTHER RENEWABLE SOURCES www.gas.asn.au. Click on the “Directory of Certified
Appliances and Components” on the home page.
Solar water heaters and passive solar building techniques
reduce the need to use non-renewable energy sources.
[See: Solar Hot Water; Passive Design Introduction]

OTHER ENERGY SOURCES

Other fuels such as coal, coke, briquettes and heating oil
Courtesy AGA

are available but should only be used in small quantities.

Air quality is an issue in urban areas for all solid fuels.
Energy Source Selection
The following, in order of priority, will minimise
environmental impacts:
The AGA label gives an efficiency rating up to six stars
> Renewable Sources - such as Green Power, use of on- and the comparative energy consumption (in the red box)
site generation and solar hot water systems. under standard test conditions.

> Hydro-Electricity in Tasmania. The higher an appliance’s star rating the better its
energy efficiency and the lower its comparative energy
> Natural Gas - or LPG when not available. consumption.
> Wood from sustainable sources - in urban areas be To estimate annual running costs, multiply the energy
aware of transport and air pollution impacts. consumption in the red box by the cost of your gas supply.
> Grid Electricity on the mainland. Locate water heaters close to those areas where hot water
is used.

EFFICIENT ENERGY USE Showers usually use the most hot water in a home. Install
AAA rated water efficient showerheads. The AAA scheme
ensures they will provide a satisfying shower.
Using energy efficiently is the best way to reduce energy
bills and environmental impacts while maintaining or even Set the thermostat between 60 to 65oC on storage hot
improving comfort levels. water systems and 50oC on instantaneous systems.

Some solutions cost nothing at all. Most investments in Insulate hot water pipes.
energy efficiency will pay for themselves through lower Turn off the hot water system when on holidays.
energy bills.
Put a timer on the electric booster of solar water heaters
and on peak electric storage systems to avoid heating
water when not needed. [See: Hot Water Service; Solar
Hot Water]

Hot water accounts for about

30 percent of household energy use.
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0.30
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HEATING AND COOLING YOUR HOME

0.25
Use high efficiency gas, electric heat pump or wood heaters
(where appropriate) for room heating rather than electric 0.20
convection and radiant heaters. Radiant heaters are suitable 0.15
for bathrooms when used for short periods of time. 0.10
0.05
0.00
Use passive design principles to ve
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kilograms of greenhouse gas generated by cooking a meal of vegetables
Gas heaters and room air conditioners have energy rating
labels. Choose the right sized heater or air conditioner for When using gas, kitchen ventilation must be adequate.
your needs with the most stars on the label. Use a range hood vented outdoors to get rid of combustion
Avoid centralised systems unless your home is well gases and steam.
insulated. Ensure centralised systems have zone controls Fan forced ovens are about 30 percent more efficient than
and thermostats. conventional units, which can waste up to 90 percent of
the energy used.
Use ceiling fans instead of air coolers. If cooling is
required, use evaporative systems in low humidity areas. Some electric ovens can be divided into compartments for
cooking small items.
If air conditioning is needed choose high efficiency
models. Look for ovens with high levels of insulation and triple
glazed, low-e coated windows.

COOKING EFFICIENTLY Avoid opening the oven door unnecessarily when cooking.
Make sure the door seal is clean and in good condition.
There are currently no energy rating labels for cookers to
help choose the most efficient models. Use a microwave when possible rather than an oven, as
they use less than half the energy.
Try not to over fill the kettle. Boil only the amount of
In general, choose gas cooktops rather water needed.

than electric. They are cheaper to use, Use a kettle or gas cooktop to boil water rather than a
microwave oven or electric cooktop.
often have more responsive controls
Efficient cooking methods such as using pots with fitted
and produce less greenhouse emissions. lids, simmering instead of boiling and using a pressure
cooker will save energy.
Match the size of pots to the size of the element or flame.
A gas cooktop will produce less than half the greenhouse
gases of a standard electric unit. Cook outside on hot days if possible to avoid heating
the house.
A gas oven will also usually produce less greenhouse gas
than an equivalent quality electric model. ELECTRICAL APPLIANCES
However some very efficient electric cooktops and ovens Electrical appliances account for about 25 percent of
are available. Ask your retailer or the manufacturer for household energy use.
information.
When purchasing white goods (refrigerators, freezers,
clothes washers, clothes dryers and dishwashers) look for
the Energy Rating Label. This label gives a star rating and
annual energy consumption for the appliance. The more
stars, the more efficient the appliance.
Choose an appliance with the highest number of stars.
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Sometimes an efficient appliance may cost a little more to Use task lighting to supplement general lighting if needed.

4 .0 E n e r g y u s e i n t r o d u c t i o n
buy, but it will soon pay for itself in reduced energy bills.
Use well designed windows and skylights to provide
Buy appliances that are the right size for you. A larger natural light while keeping winter warmth in and summer
model will use more energy than a smaller one with the heat out. [See: Lighting]
same star rating. Always check the energy label for the
number of kWh (units of electricity) used per year. REDUCING STAND-BY ENERGY CONSUMPTION
Choose appliances with a ‘AAA’ rating for water Stand-by energy is drawn when some electrical equipment
efficiency. [See: Reducing Water Demand] is not actually being used, such as when the TV is turned
off with the remote control rather than with the switch on
the set or at the wall. It is sometimes used to power digital
displays or maintain memory settings, but often it is just
Choose appliances with energy or wasted energy.
water saving features, such as Be aware of the standby energy use of electrical equipment
clothes washers with cold wash such as TVs, videos, clocks, computers, faxes, microwaves,
security systems, battery chargers and power packs.
cycles, economy or “eco”cycles
and load size selection.
Stand-by energy use can
account for 10 percent or more
Avoid using appliances unnecessarily. Dry clothes on a
of household electricity use.
line rather than in the clothes dryer.
Follow the manufacturer’s instructions for defrosting
fridges and freezers. Some appliances, such as videos and microwaves with
digital displays, can use much more energy over a year in
Use appropriate load sizes for clothes washers and
standby than in actual operation.
clothes dryers.
Standby energy consumption can be reduced by using
Locate appliances that use hot water as close to the hot
appliances endorsed with the ENERGY STAR® logo.
water service as possible to reduce heat losses in pipes.
ENERGY STAR® is an international
Use cold wash cycles and other energy saving features.
standard for energy-efficient
Maintain your appliances according to the manufacturer’s electrical equipment developed
instructions. An appliance in poor condition usually uses by the US Environment
more energy than one in good condition. [See: White Protection Authority.
Goods]
The standard only applies to stand-by energy use and does
not cover energy used during operation, although ENERGY
LIGHTING STAR® equipment is often more efficient in operation too.
Use fluorescent or compact fluorescent lamps instead of Electrical equipment that meets the required efficiency
incandescent bulbs in areas that are used a lot, like living standard is labelled with the ENERGY STAR® logo.
rooms and kitchens. In Australia, the program already applies to office
Avoid using low voltage downlights for general lighting as equipment such as computers, printers, fax machines and
they are not energy efficient. photocopiers. From mid-2001 it will apply to home
entertainment equipment such as TVs, VCRs, audio
Turn off lights when not needed. equipment and DVD players.
Use timers or sensors on outdoor security lights.
More information is available on the ENERGY STAR®
Use separate switches for each light fitting. website at www.energystar.gov.au
Consider using solar lighting for outdoor areas. The ENERGY STAR® function is not always enabled on
Use the minimum wattage lamp to provide sufficient light. new appliances. Ask your retailer to enable it or follow the
directions in the instruction manual. Switch equipment off
at the power outlet when possible because even ENERGY
Fluorescent bulbs use about one STAR® equipment still uses some standby power.
quarter of the energy of normal bulbs.
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HOME OFFICE AND ENTERTAINMENT EQUIPMENT

CONTACTS
Ensure equipment is ENERGY STAR® compliant and make Australian Capital Territory
sure that it is enabled. Energy Advisory Service
Master Builders’ Association
Large screen TVs use more energy than those with smaller
Phone: 02 6247 2126 Internet: www.mba.org.au
screens.
New South Wales
If buying a computer consider buying a laptop – they Energy Smart Information Centre
require less materials to make and less energy to run. Phone: 1300 363 768 Internet: www.energysmart.com.au
An LCD screen for desktop computers will use less energy Northern Territory
and take up less space. Natural Resources Division
Department of Lands, Planning and Environment
Switch off computers and printers if you won’t be using Phone: (08) 8999 4413 Internet: www.lpe.nt.gov.au
them for half an hour or more.
Victoria
Look for printers and faxes and that can use recycled Sustainable Energy Authority
paper. Use recycled ink and toner cartridges. Reuse blank Energy Smart Advisory Centre
sides of used paper. Phone: 1300 363 744 Internet: www.sea.vic.gov.au
Queensland
Switch off equipment at the wall instead of leaving in
The Office of Sustainable Energy
standby mode, especially when you go on holiday. Energy Advisory Service
Phone: 1300 369 388 Internet: www.dme.qld.gov.au
Other Appliances and Equipment
South Australia
There are many small items around the house that can use Energy Information Centre
a lot of energy over a year, such as pool filter pumps, Toll free: 1800 671 907 Internet: www.pir.sa.gov.au
electric towel rails, computer games, etc. Ensure they are Tasmania
not left on unnecessarily. Environment, Planning and Scientific Services Division
Department of Primary Industries, Water and Environment
Phone: 03 6233 6518 Internet: www.dpiwe.tas.gov.au
Western Australia
Office of Energy, Western Australia
Phone: 1300 658 158 (Home Energy Line)
Internet: www.energy.wa.gov.au

ADDITIONAL KEY REFERENCES

‘Global warming, Cool it’ available on Australian Greenhouse
Office website www.greenhouse.gov.au
AGO Infoline 1300 130 606
Internet: www.greenhouse.gov.au

Principal author: Geoff Milne

Contributing author: Chris Riedy