Look before we leap: Desalination Thanks to https://plus.google.com/u/0/+DianaStuder for the heads up on this topic!
Look before we leap: Desalination Thanks to https://plus.google.com/u/0/+DianaStuder for the heads up on this topic! From the article:
"...To make large volumes of freshwater from salty water needs large quantities of energy. Depending on which method is used to desalinate (reverse osmosis/vapour compression/ membrane distillation) between 2 and 12kWh of electricity are needed per 1 000 litres...."
A vicious circle: "Concerns have been raised in the United States that electricity supplies in local grids are not able to accommodate new desalination plants built in response to the Californian drought." So more electric generating facilities are needed, hopefully solar or wind and the grid may have to be upgraded, too.
As usual, waste is a concern: "Desalination plants need to take in twice as much seawater as they produce freshwater. Often the intake points take in small organisms (fish larvae, plankton, etc) which can reduce local fish populations. A quantity of very concentrated brine is then produced, which generally will be disposed of back to the sea. As well as being very salty (which is toxic, even in a marine environment) this brine contains biocides and antifouling chemicals used in the desalination process which can also harm marine life."
Conservation is cheaper: "In Australia, the severe drought from the mid-1990s until 2012 prompted the construction of six large-scale seawater desalination plants at a cost of $10 billion Australian Dollars. The plants took years to build. Meanwhile, the National Water Initiative implemented water policy reforms and improved efficiency measures that led to cheaper water supply alternatives. By the time the plants were operational, the drought was over and the more cost-effective alternatives made desalinated water prohibitively expensive. Most of these facilities have stood idle, and operated at a significantly reduced capacity."
For further information, contact the International Desalination Association via [ http://idadesal.org/ ]
#EnvironmentalPolitics
#Desalination
http://www.wwf.org.za/?24281/wednesday-water-file-07
"...To make large volumes of freshwater from salty water needs large quantities of energy. Depending on which method is used to desalinate (reverse osmosis/vapour compression/ membrane distillation) between 2 and 12kWh of electricity are needed per 1 000 litres...."
A vicious circle: "Concerns have been raised in the United States that electricity supplies in local grids are not able to accommodate new desalination plants built in response to the Californian drought." So more electric generating facilities are needed, hopefully solar or wind and the grid may have to be upgraded, too.
As usual, waste is a concern: "Desalination plants need to take in twice as much seawater as they produce freshwater. Often the intake points take in small organisms (fish larvae, plankton, etc) which can reduce local fish populations. A quantity of very concentrated brine is then produced, which generally will be disposed of back to the sea. As well as being very salty (which is toxic, even in a marine environment) this brine contains biocides and antifouling chemicals used in the desalination process which can also harm marine life."
Conservation is cheaper: "In Australia, the severe drought from the mid-1990s until 2012 prompted the construction of six large-scale seawater desalination plants at a cost of $10 billion Australian Dollars. The plants took years to build. Meanwhile, the National Water Initiative implemented water policy reforms and improved efficiency measures that led to cheaper water supply alternatives. By the time the plants were operational, the drought was over and the more cost-effective alternatives made desalinated water prohibitively expensive. Most of these facilities have stood idle, and operated at a significantly reduced capacity."
For further information, contact the International Desalination Association via [ http://idadesal.org/ ]
#EnvironmentalPolitics
#Desalination
http://www.wwf.org.za/?24281/wednesday-water-file-07
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