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Water and electricity are more closely linked than many of us may have imagined and the relationship between them needs to be given more attention. Debborah Marsh’s Doctoral research examined closely the nexus between water and energy in NSW and how some of the unintended outcomes of the water and energy markets need to be addressed. | | In recent decades, developments in water and energy policies have been spurred by the Council of Australian Governments COAG). This has resulted in an emphasis on market-based reforms and the establishment of the National Electricity Market and a pilot rural water market in the late 1990s. For example, in NSW energy can be provided from Energy Australia, Integral Energy or Country Energy all buying (in bulk) and selling electricity. This competition is also being considered in the urban water sector, in terms of the provision of recycled water by private companies.
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However, these policy developments have all been taken separately, overlooking the links between energy and water and producing unintended outcomes. One such example occurred in 2007 and related to the extensive period of drought in much of the state. It is important to note that coal fired (and most gas fired) power generators use large amounts of water for their boilers and for cooling. However electricity was still being generated in regions where there were severe water shortages and then traded on the market to areas that had their own adequate capacity to generate more electricity.
As a result, the market mechanism effectively traded the water out of the areas where it was needed. In a country where water is a growing problem, this needs to be addressed.
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The graph below compares the relative water required to produce the same quantity of electricity by different technologies. Note that the 'embedded water' - water used in the manufacture of the electricity generation plants has been included for each method. |
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Most water suppliers, on the other hand, depend on large amounts of electricity to treat and transport water where it is needed. Increasingly they are also looking at ways of making water treatment non-rainfall dependent. However, such advanced waste water treatment technologies tend to require massive amounts of electricity to achieve that aim. A desalination plant, for instance, takes around 4 kilowatt hours of electricity to produce a kilolitre of water whereas recycling uses around 1.5 kilowatt hours to produce a kilolitre. Conventional treatment processes use about 0.7 kilowatt hours for every kilolitre produced. It is sobering news. Water is a large part of electricity generation and electricity is a major component of water delivery. The development of separate energy and water markets has ignored the links between them and given credence to technological options that creates further stresses on both.
The water consumption by these various technologies is compared in the next graph. Note that the bars indicate the electricity consumption range.
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Debborah Marsh argues that the delivery of water and energy from centralised concerns have no incentive to explore other, more symbiotic relationships. While home water tanks are provided with rebates in some areas, no one questions the energy use of the pumps required to move that water, most of which are energy inefficient. Debborah’s research shows that this blanket approach to the water/electricity nexus does not necessarily provide what is needed at a local level. She argues that there needs to be a balance between the extremes of centralised and decentralised delivery of electricity and water. This would mean that local areas would have a say in how water and electricity are delivered, something that challenges the “owner pays” system. Large rainwater tanks, for instance, shared by local residents, community organisations and businesses may be a better model for some areas than individual ones. Power generators based in areas with access to less drought affected water may be a better bet than stripping water from local communities to produce electricity.
Text: V.B. December 2008 Illustrations from Debborah Marsh
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