Energy Use
Energy use in water and wastewater management is linked to climate change at a global scale.
A number of National and Western Australian initiatives are being undertaken to help to manage energy across the community, as part of global efforts to reduce the forecasts for global warming:
- the National Framework for Energy Efficiency has been developed with the aim of achieving a major enhancement of energy efficiency performance, reducing energy demand and lowering greenhouse gas emissions;
- the Commonwealth ‘Energy Efficiency Opportunities Act 2006’ has been enacted to mandate the assessment, monitoring and reporting on energy use and energy efficiency actions; and
- a mandatory Energy Efficiency Program has been developed in Western Australia to work with industry to develop a mandatory energy efficiency scheme applicable to large and medium sized power consumers. The Water Corporation is working collaboratively on this initiative.
In 2006 - 07 the Water Corporation used 1.6 million gigajoules of energy in the following areas:
- 90% from electricity;
- 8% for transport; and
- 2% for heating using natural gas and biogas.
The Water Corporation’s energy consumption is directly related to three major factors:
- number of customers;
- level of water or wastewater treatment required - the higher the quality of water and wastewater required, the more energy is used to treat it; and
- the distance over which water and wastewater is transported.
Almost 70% of all energy use is attributed to water services with a further 20% due to wastewater services. Support activities such as energy use in buildings and transport account for the balance.
New rainfall independent sources tend to use more energy as they often require higher levels of treatment. The energy needed to treat 1 kilolitre of drinking water varies by source as follows:
- 0.4 to 0.6kWh for water treatment of surface and groundwater sources;
- 0.8 to 1.0kWh for recycled water; and
- 3 to 5kWh for reverse osmosis desalination of seawater.