What is it?
Desalination plants turn saltwater into freshwater. The desalination process is fairly simple, the most common Australian process is called reverse osmosis, water is pumped under pressure through a membrane that separates most of the water from the salt. The salty water, called brine, is pumped back into the ocean and the freshwater is pumped into our cities.
How is it used?
Check out this video to see how salt water can be converted to drinking quality water.
Where is it being used?
In Australia many of our cities now use desalination plants. Perth has two desalination plants while Sydney, Melbourne, Adelaide and Brisbane have desalination plants ready to use if we need.
While desalinated water makes up part of the mix in some of our major cities, it is also a primary source of water on ships and for many tropical island resorts, like Heron Island, where fresh water isn’t available.
New technology has reduced the cost of desalinated water and how much energy is required, but it is still more expensive than fresh water.
What are some of the benefits of desalination?
People, particularly in large cities, need a lot of fresh water and if it doesn’t rain then large cities can simply use more freshwater than they can store. However saltwater from the ocean is a practically limitless supply of water close to most large cities.
What are some of the issues with Desalination?
Why is desalinated water more expensive? Firstly, desalination needs more energy to produce, at least 15 times more than water from a big dam. Secondly the desalination plants are quite expensive, Australia was reported to be spending $13.2 billion on desalination plants in 2011 in response to national water shortages. Most of these plants are not being used at the moment, but when the weather turns dry again projected demand means we may need to build even more.
Although desalinated water has been criticised, at the end of a long drought when the dams are nearly dry you might be very happy to be able to drink it. The important thing is to pick the right water source from the available options to provide an environmentally sound and cost effective option.
Have you tried desalinated water?