Worth its salt: Can desalination help address Europe's freshwater needs?

Desalination is the process of removing salt from seawater or brackish water to make it useable for people in a range of purposes, including drinking. It is seen as a drought-proof alternative to water supplies threatened by climate change. Several southern EU countries rely on it to provide freshwater, for drinking and agriculture.

But desalination plants are expensive to build and run, and use a lot of energy, although new technologies are reducing costs and the environmental impact. 

They can also have an adverse environmental impact on marine animals and plants. Desalination produces a byproduct called brine - a concentrated salt solution with chemicals.

When discharged back into the sea it can harm fish, coral and plankton. Many consider desalination a ‘last resort’, only to be used once all other options such as reusing wastewater and reducing leaks have been tried.

But while the technology has significant drawbacks, without it, some EU regions would not be able to meet their water demands.

Desalination is already widely used in Spain, Cyprus and Portugal. Greece and Italy are expanding too. In some regions of Europe we won’t be able to meet demand fully unless we both reuse wastewater and desalinate some sea water.

·         The latest update of the Taxonomy Regulation (a cornerstone of the EU’s sustainable finance framework and an important market transparency tool) classifies desalination as a “green” investment under strict conditions related to environmental aspects. Green energy should be used as much as possible and brine must be reduced and in case of discharges must be safely treated and diluted in sea water.  

·     Desalination has drawbacks, including high energy consumption and maintenance, and disposal of