Human Settlements Theme Report
Australia State of the Environment Report 2001 (Theme Report)
Lead Author: Professor Peter W. Newton, CSIRO Building, Construction and Engineering, Authors
Published by CSIRO on behalf of the Department of the Environment and Heritage, 2001
ISBN 0 643 06747 7
Urban stocks and processes (continued)
Australia's non-renewable energy reserves-fossil fuels and uranium-are very large in comparison with our annual energy use, as shown in Table 20. Australia has been capitalising on this endowment to drive its post-war economic growth (Figure 25). It seems, however, that our use of these resources in the future is much more likely to be constrained by the environmental impacts of their extraction and consumption, rather than their availability.
|Energy resource||Demonstrated resources||Inferred
|Black coal||1 311||161||Very large||5.9
|Brown coal||370||27||1 498||0.6
|Shale oil||0||183||1 534|
|Solar radiation - annual insolation on Australia||63 000
ADemonstrated resources are those that are known to exist with a reasonable level of certainty. Economic resources are those which could be extracted with known technologies at prices that were competitive in late 1990's circumstances. Subeconomic resources are those that require further reductions in production cost or higher prices before they would be economic. Inferred resources are those believed to exist based on geological knowledge, but have not yet been confirmed.
C Naturally occurring.
Source: Converted to energy units from Bush et al. (1999). Solar radiation data from Gavin and Guthrie (1991).
Source: ABARE (1997); Snooks (1994); Vamplew (1987); Poldy and Foran (1999)
The exception to this situation is oil, which is not an abundant resource in Australia. Our lack of oil resources is potentially a problem, as world oil resources are also relatively scarce and are concentrated in the Middle East. Australia produces quantities of oil roughly equivalent to its annual oil demand, but this obscures a key resource issue. In reality, over 60% of the actual oil (by energy content) used in Australia is imported. In particular, we rely heavily on imported oil for diesel fuel, which is essential for farming and freight transport.
From a strategic perspective, this leaves critically important industries vulnerable to international oil prices and availability. However, it is possible to supply petroleum replacements from natural gas, coal or shale oil, although production of the latter two options, in particular, has significant environmental impacts. Renewable diesel fuel substitutes are also available. For these alternatives to be available at a future time, before there is a critical shortage of diesel fuel, a consistent strategy that supports their development is needed. Development of renewable alternatives to petrol will also be necessary if transport is to move towards sustainability.
Australia's renewable energy resources are not well documented, but are enormous. A week's sunshine falling on the Australian continent delivers as much energy as would all of our demonstrated conventional energy resources, and our total annual energy production from conventional energy sources is equivalent to less than two hours of solar radiation falling on Australia. Wind, waves and falling water provide large additional renewable energy resources. For example, 1-2% of the energy from solar radiation is converted into wind energy. Biomass, which really is stored solar energy, is also an important renewable energy resource, although debates about environmental impacts from harvesting biomass from forests, concerns about loss of soil nutrients through harvesting, and possible conflicts between food and energy production place limits on its use. Geothermal energy, particularly in hot rocks several thousand metres below the Earth's surface, has also been identified as an enormous energy resource. Table 21 shows a variety of renewable electricity sources now in use. However, renewable resources can also supply heat and transport fuel, which comprise the bulk of energy services required by Australians.
|Resource-technology combination||Installed capacity (MW)||Electricity generated (GWh/year)|
|Large hydroelectric||7 580||16 000|
Bagasse cogeneration (sugar industry)
Black liquor (paper industry)
|Wind - main grid||0.2||0.4|
|Wind - small grids||2.5||4.4|
|Photovoltaic grid connections||0.14||0.3|
Photovoltaic remote area power systems (RAPS)
|Solar hot water (water heating electricity displaced, not actually generated)A||190||500|
|Total||8 390||18 200|
A This table was prepared as background to the development of the Commonwealth '2% Renewables' target, which will require electricity suppliers to deliver 9500 GWh more electricity from approved renewable energy sources installed after 1997. Although solar water heaters do not actually generate electricity, they displace electricity that would have been used to heat water, and the government has included them in the scheme.
Source: Redding Energy Management (1999).
The environmental impact of energy use can be further reduced by appropriate use of renewable energy sources to supplement and eventually replace most fossil fuel use. However, inappropriate development of renewable energy can create its own environmental impacts. For example, burning wood in open fires is extremely polluting, while the location of wind generators in areas of high aesthetic value might also have a negative environmental impact. It is therefore important to combine maximum efficiency with utilisation of renewable energy.
Australia's measured energy flows are shown in Figure 26. The diagram does not include natural energy flows which, as noted in Table 21, are very much larger. As indicated earlier, Australia produces all of the primary energy resources it uses, except for some oil which is imported. It exports large quantities of oil, coal, gas (as liquefied natural gas) and uranium. Primary energy resources are converted into energy forms that can be used by consumers. Most of Australia's coal, some gas and small quantities of other fuels are converted into electricity, but over two-thirds of this primary energy is dissipated in conversion losses. Oil and natural gas are refined or processed to remove impurities and convert them into products, such as petrol and diesel oil, suitable for use by consumers. The energy is delivered to consumers via an extensive network of pipelines, transmission cabling and a commercial transport fleet.
Figure 26: Australia's energy flows.
Source: Bush et al. (1999); activity data was sourced from Wilkenfeld and Associates (1998)
On the consumer side of the meter, households and business own a variety of equipment that consumes energy to deliver useful services such as travel, space heating, cooking and operation of equipment. The mix of energy sources varies from sector to sector (and within sectors); transport uses mostly oil, while households and commerce use a high proportion of electricity. Choices consumers make about the equipment they purchase, and the ways they use it, influence the quantities of each type of energy they consume.
In Figure 26, the activity breakdown within each sector is shown as a percentage of that sector's greenhouse gas emissions, as estimated by Wilkenfeld and Associates (1998) for 1995. Presenting information in this way instead of by the amount of final or delivered energy used for each activity provides a more accurate indication of the environmental impact of those activities. For example, household refrigeration would seem like a minor issue if the amount of electricity consumed were shown. But since each unit of electricity consumed requires the burning of more than three units of coal energy, its actual significance in terms of primary or total energy use, and in terms of greenhouse gas emissions, is much greater.