I’ve just read an article in The Australian regarding a possible sweetner for the Bracks government, namely consideration of a $1.5 billion pipeline to supply Melbourne with water from the Murray river system.
I haven’t found what the other options — desalination, reuse of stormwater and a scheme to use waste water to replace water used by power generators in the Latrobe Valley — were going to cost the Victorian goverment but I’m blown away with spending $1.5 billion for 150 gigalitres per year. And the water will have to be sourced from consumptive users and almost certainly not from environmental flows.
Maybe the $1.5 billion price tag includes the cost of purchasing this water, if not it will add another $ 2-300 million.
To my way of thinking that leaves the capital cost in the region of $10-12 million per gigalitre, or $10-12,000 per megalitre. The opportunity cost of that money will hover close to $1,000 per megalitre let alone any pumping, cleaning, maintenance and payback for the $1.5 billion outlay. And if we account for the lost agricultural production(say $250 per megalitre) due to the loss of the water, then cost per megalitre approaches $2,000.
And to top it all off we’re not harnessing any new water for that outlay.
I can’t begin to guess what it would cost to harvest storm water, which is wasted at a cost to the environment, or getting waste water to power generation sites, at least doing either ‘create’ new water. Water that can be used without infringing on anyone. I’ll assume this is an expensive option.
I do note the Victorian government hasn’t mentioned recycling.
What I do have, is some understanding of desalination. One of the more recent installations is in Ashkelon, Israel. This plant has a capital cost of about $300million( US$250m) to produce 110 gigalitres per year at a cost of $700 per megalitre (52 cents US/m3)
Desalination of seawater takes 3-4kw of electricity to produce a m3 (1,000 litres).
This desalination plant has it’s own gas fired 80MW power station. I would guess such power consumption will have some people jumping up and down, but to put 80 MW into perspective it is less than 1% of Victoria’s generating capacity of 9,000 MW and is close to 10% of Victoria’s current (no pun intended) renewable electricity output of 767 MW of which 580 MW are hydro generated.
All we need to do is expand renewables by 10% to keep blood pressures in check.
A Texas site on desalination supports the Israel experience. Though slightly more expensive – those Israeli’s know how to drive a bargain.