DeSal plants only work when the economics are right. With current technology the capital costs are relatively fixed but the operating costs (largely the cost of large energy needs) and the value of the water determine if an area is economically viable. The wild card of course is government intervention where budgets could be adjusted to pay for a desal that would lose money without subsidy.
For WA desal makes sense since there is hundreds of years of natural gas supplies (mostly undeveloped). The government supplies water, derives revenue from otherwise stranded gas and HAD the surplus funds to fund the capital works. The next one will be harder under the current economic climate.
In California things are different although the need for water is greater. Here the governmental style is more capitalist and the state is a large importer of gas (they import 90% and use much more gas a day than all of oz). They have had desal for awhile but the cost of gas has until recently left the Carlsbad plant inactive. http://www.bloomberg.com/news/artic...ees-salvation-in-seawater-as-drought-drags-on
Queensland has a large amount of undeveloped gas but in unconventionals. Victoria and NSW do too but these have prevented even in the appraisal stage. Is this a place for the government/public to be pragmatic and use their natural resources to supply water? Can they say the F word?
Obviously in all cases other energy could be used but currently other than nuclear (a whole different subject) most areas do not have another choice without further technology advancements.
