State of the Environment Report 2007
Energy is a fundamental resource for human settlements: it is used during their construction, (e.g. roads, buildings and building materials), operation (e.g. homes, offices, transport networks) and is fundamental to liveability (e.g. televisions, air conditioners, cooking, computers, etc.). The focus of this issue is on residential energy use (energy used in homes), while the broader energy sector is addressed in 'Towards Sustainability'.
Western Australian households use a considerable amount of energy directly through consumption in the home, and fuel use in private travel. Households are also indirectly responsible for a large amount of energy use, required in production and freight of the goods and services they consume. It has been estimated that Australian households are ultimately responsible for over half of total energy use in Australia, either directly or indirectly through the consumption of products and services (Australian Bureau of Statistics, 2001a). Nearly all energy supply to the State's settlements comes from non-renewable fossil fuel resources (including petroleum products, coal, and natural gas).
Due to the vast size of WA and inaccessibility of many settlements, transmission and distribution of centralised fossil fuel-based electricity to the whole State is expensive, inefficient and unreliable (Sustainable Energy Development Office, 2005). There is a substantial quantity of these low-cost fossil fuels in WA (namely coal and natural gas), but generating and utilising the energy emits large amounts of greenhouse gases and particulate matter into the atmosphere. These emissions are harmful to human health and to the environment.
'Residential energy use' is expressed in final energy terms, which includes direct energy use in the residential sector from electricity, natural gas, wood, oil and related products. It excludes energy consumed to generate electricity. Residential energy also excludes embedded energy used to produce construction materials, build homes, or manufacture and transport goods that are consumed by households.
Residential energy represents less than 5% of total energy use in WA, but has been growing at an annual average rate of 2.2% since 1990 (Figure HS4.1). This is attributable to increasing population and per capita consumption. Total residential energy use in WA was around 34 petajoules in 2004-05.
Peak electricity demand on the South West Interconnected System has grown at a significantly higher rate than average demand growth. Households and commercial businesses have a significant influence on peak demand for electricity, mainly due to air conditioners and other temperature-sensitive loads (Western Power, 2004). Peak electricity demand is forecast to grow 25% faster than average electricity demand over the next 10 years (Independent Market Operator, 2005). Disproportionate growth in peak demand is important from an environmental perspective, because it necessitates development of new electricity supply infrastructure which is only used for a short time period each year.
![Figure HS4.1: Total and per capita residential energy use in Western Australia, 1990–2005. [Data source: Australian Bureau of Statistics (2006a), Australian Bureau of Agricultural and Resource Economics (2005).]](/site/files/images/Figure-HS4.1_Large.jpg)
Since 1990, per capita residential energy use has grown about 11%, from 15.5 gigajoules per capita in 1990 to 17.2 gigajoules per capita in 2005 (Figure HS4.1). The rate of growth in per capita residential energy consumption has slowed considerably since the mid-1990s and has even declined slightly since 2003.
The increase in per capita residential energy use reflects the increasing number and use of appliances, and increased home heating and cooling. It also reflects the trend towards smaller households with larger homes. The majority of energy consumption in homes is for home heaters, air conditioning, and hot water systems although this varies depending on geographic location.
Average residential energy use per household in WA varies across the State (Figure HS4.2). The South West Interconnected System is WA's main electricity network, covering the south-west corner of the State from Kalbarri to Albany, with a spur out to Kalgoorlie. In 2004, average electricity consumption of households connected to this system was approximately 5500 kilowatt hours (kWh), or 15 kWh per day. Households connected to the North West Interconnected System, which services Port Hedland, Karratha and Roebourne, consumed on average nearly 12 000 kWh, or 32 kWh per day, more than double the usage rate in the south. The remainder of the State is supplied by Western Power's Regional Network System, with average electricity consumption for households of 7600 kWh, or 20 kWh per day. While reticulated natural gas supply in the Perth region may account for some of the difference in electricity consumption patterns among different settlements, anecdotal evidence suggests air conditioning is the main reason for consumption differences between the State's north and south. The average rate of electricity consumption per household is increasing in most of WA's settlements (Figure HS4.2).
![Figure HS4.2: Trend in average electricity use per household in Western Australia, by settlement 1998–2004. [Data source: Western Power; Analysis: EPA; Presentation: EPA. Note: Based on average electricity consumption by residential customers of Western Power.]](/site/files/images/Figure-HS4.2_Large.jpg)
Renewable energy resources reduce greenhouse gas emissions resulting from energy use and provide a viable alternative form of energy supply for remote communities. Only 2% of all energy used in WA comes from renewable sources. Solar water heating is one of the most common forms of renewable energy used in WA homes. The current market penetration of solar water heaters in new and existing WA homes is approximately 15%, the majority of which are electric boosted solar (Australian Bureau of Statistics, 2005a).
Households and businesses connected to the South West Interconnected System can purchase electricity generated from renewable energy sources through Western Power's accredited Green Power product, NaturalPower. Green Power is a national renewable energy program where consumers opt to pay a premium to have their consumption provided by renewable energy. The price premium subsidises and drives demand for renewable energy. Currently less than 0.5% of Western Power residential customers purchase Green Power. During 2004, the number of NaturalPower customers in WA increased by 21% to 1004, of which 90% are residential customers (URS, 2005). In comparison to other states and territories, WA has the lowest participation in Green Power in Australia (Figure HS4.3).
![Figure HS4.3: Residential customer participation in Green Power by state and territory, as at 31 December 2004. [Data source: URS (2005).]](/site/files/images/Figure-HS4.3_Large.jpg)
Western Australia's population growth and increasing urbanisation are significant pressures leading to increased energy use in the State's settlements. This increases demand for new power stations and expansion of the capacity of existing stations. It also requires significant new infrastructure for transmission.
Consumer trends and behaviour patterns are also leading to increased consumption of energy in homes. Increased affordability and use of electronic appliances (e.g. dishwashers, air conditioners, computers, televisions, etc.) is contributing to this trend. Average household size in WA is declining, while the average floor space of new dwellings is increasing. These trends can contribute to increased energy use, particularly as more energy is required for home heating, cooling and lighting.
National Framework for Energy Efficiency: has been developed through a joint State-Commonwealth Government initiative. The framework defines future directions for energy efficiency policy and programs in Australia and aims to achieve major improvements in energy efficiency, reduce energy demand and lower greenhouse gas emissions (National Framework for Energy Efficiency, 2006).
Energy programs: The Sustainable Energy Development Office administers a number of programs for energy efficiency and renewable energy in settlements. The Renewable Remote Power Generation Program provides rebates for renewable energy systems in remote settlements and on the fringes of the electricity grid. As of November 2005, the program had funded a combined capacity of around 1.2 megawatts of small-scale renewable energy systems (Sustainable Energy Development Office, 2005).
Solar water heater subsidy: provides rebates to households that install gas-boosted solar water heaters. Sales of gas-boosted solar water heaters in WA grew at156% per annum between 2002 and 2004, compared to the national average of 32%, with the majority of systems installed in new homes (Sustainable Energy Development Office, 2005).
Photovoltaic rebates: Rebates are available for homes, and community buildings such as schools, for installation of photovoltaic (solar) power systems. The Sustainable Energy Development Office also provides funding to communities for innovative renewable energy and energy efficiency projects.
Energy efficiency standards: The State Government has been progressively implementing thermal energy efficiency performance standards for new residential buildings, as specified in the Building Code of Australia. It is also trialling AccuRate, energy efficiency software, for application in new homes, and in additions and alterations to existing homes. AccuRate is a building star-rating program that is designed to assess the energy efficiency of dwellings.
Planning tools: The Department for Planning and Infrastructure is developing a WA version of BASIX. This web-based planning tool, used by the NSW Government, allows designers of new homes to achieve reductions in energy and water use compared to calculated benchmarks. The department is also giving consideration to a similar tool, Retrofix, for existing homes.
NaturalPower: is a program offered by Synergy that allows residential and commercial customers to choose to pay a premium to have their electricity provided by renewable sources. NaturalPower is accredited by the National Green Power Accreditation Program.
Emissions offsets: Synergy offers 'Earth Friendly' electricity, in which the greenhouse gas emissions from electricity generation are offset through contributions to greenhouse abatement programs like tree planting and diverting organic waste from landfill.
Under current trends, energy consumption in WA's settlements is expected to continue to increase. Peak energy demand has been a particular problem for Perth in recent years, particularly with high summer temperatures and increased ownership of air conditioners. Consequent greenhouse gas emissions from growth in energy use will also continue to increase unless there are significant shifts toward greater use of renewable energy and improvements in energy efficiency.
7.18 Implement the National Framework for Energy Efficiency.
7.19 Implement BASIX in the development of new houses and promote Retrofix for established houses.
7.20 Provide better financial incentives to customers to establish private renewable power generation and sell energy back to the State's energy grids.
7.21 Make solar water heaters mandatory in all new houses.
See also 'Energy':
