Households in Perth and the South-West must start drinking recycled water within three years or be prepared to pay $1 billion for a third desalination plant within a decade, according to Daniel Mercer’s article
Dry climate limits water options in the
West Australian on 11 July.
Mr Mercer’s article quotes Peter Moore, Chief Operating Officer of the Water Corporation, who warned Perth’s climate was drying much quicker than predicted and the Government would have to choose another major drinking water source for the city and wider South-West.
The article went on to say Mr Moore suggested a desalination plant would need to produce at least 45 billion litres a year to be efficient (about the same size as the Perth Seawater Desalination Plant at Kwinana) and Perth’s northern water network would need significant upgrades to accommodate it.
Does a new desalination plant need to cost this much?
During the Millennium drought, Australia built six large desalination plants (by world standards) and a potable water recycling system in all mainland state capitals at a cost of more than $12 billion. With the exception of the first (the Perth Seawater Desalination Plant at Kwinana where the cost is around $1.20 per kL) the water produced from Australia’s desalination plants is quite expensive at $US2 to 3 per kL. In fact, it is three to five times more expensive than water produced, for example, in Israel’s five largest desalination plants.
Is there a way we can produce water in Australia from the sea for less than say $US1 per kL? I believe there is.
Rather than just building one 45 billion litre per year desalination plant in the north of Perth, we believe construction and ongoing costs could be significantly reduced if a number of smaller plants were installed along the coast delivering desalinated water into existing water supply systems, reducing large new delivery infrastructure costs.
A number of identical plants would enable a production line approach to construction offering savings and could enable efficient local manufacture of an assembly of reverse osmosis trains, pipework, buildings and electrical controls. Smaller plants could also be staged, and built when needed, reducing the need for large land acquisition and associated environmental and landscaping costs.
There would be low visual and environmental impact with smaller plants able to be located in existing harbour, industrial or commercial areas. They may be able to use beach well intakes where seawater is filtered through natural beach sand or subsurface strata, substantially reducing the need for pre-treatment, which normally requires expensive multi-media or membrane filtration. This has been successfully implemented overseas on large desalination plants at Fukuoka, Japan; Sur, Oman and San Pedro del Pinitar in Spain.
http://desalination.edu.au/2013/07/cheaper-seawater-desalination/#.VXoUrUYVR8G
Think our SuperSand and membrane technology could do the business much cheaper.
Raider
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