04.10.2024

Can desalination help meet Europe's fresh water needs?

The desalination process has been around for centuries, but has had only limited success in providing fresh water to humans. The EU is exploring ways to make it a viable solution to future water shortages, it reports Euronews.

Desalination is the process of removing salt from sea or salt water to make it usable by humans for various purposes, including drinking. It is seen as a sustainable alternative to water supplies threatened by climate change. Several southern EU countries rely on it to provide fresh water for drinking and agriculture.

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

They can also have adverse environmental effects on marine animals and plants. Desalination produces a by-product called brine – a concentrated salt solution with chemicals.

When discharged back into the sea, the brine can harm fish, corals and plankton. Many consider desalination a "last resort" that should only be used after all other options, such as wastewater reuse and leakage reduction, have been tried.

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

What is the EU policy on desalination?

Desalination is already widely used in Spain, Cyprus and Portugal. Greece and Italy are also expanding the technology. In some regions of Europe, demand will not be fully met unless wastewater is reused and part of the seawater desalinated at the same time.

The latest update of the Taxonomy Regulation (a key element 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 salt water should be reduced and in case of discharge it should be safely treated and diluted in seawater.

Desalination has disadvantages, including high energy consumption and brine maintenance and disposal. The new desalination plants should come after major efforts to protect and restore the water cycle and ensure the efficient use of water by promoting reuse, reducing water leakage, etc. Desalination should only be undertaken when environmentally better alternatives are not available and should be within the framework of integrated water management, with a fair balance between water supply and demand.

What are the benefits of desalination?

Desalination has emerged in response to water scarcity, particularly in Mediterranean countries, often in combination with wastewater reuse and increased efficiency.

Several southern EU countries use desalination to help meet fresh water needs. However, in the EU, a small proportion of fresh water is produced by desalination of seawater.

EU facilities can deliver up to 2,89 billion m3 of desalinated water per year.

71% of produced water is used for public water supply (2 billion m3, 4,2% of total water used for public water supply). 17% of desalinated water produced in the EU is used for industrial applications, 4% in power plants and 8% for irrigation.

EU desalination plants are mainly located in Mediterranean countries: around 1200 plants provide a capacity of 2,37 billion m3 (82% of the total EU desalination capacity)

EU funding for desalination research totals €81,5 million for the period 2014-2019, focused on infrastructure investment and innovation activities.

What are the disadvantages of desalination?

Desalination plants are expensive to build and operate. The cost of water produced by desalination is very high. Therefore, it is mostly used for the production of drinking water.

This is an energy-intensive process and it is essential that it be carried out using renewable energy and reduce its energy consumption.

Desalination produces a by-product, brine (concentrated salt solution with chemicals), which must be disposed of properly to avoid adverse impacts on the marine environment.

The construction of infrastructure such as pipes will also result in permanent alteration of hydrographic conditions (eg sediment change) and may affect marine life.

What are the financial rules governing desalination in the EU?

The latest update of the Taxonomy Regulation classifies desalination as a "green" investment under strict conditions related to environmental aspects.

Desalination projects must meet strict criteria under the EU taxonomy, ensuring that they contribute to sustainable water use and protection while minimizing environmental impact.

The criteria include efficient use of energy, low greenhouse gas emissions and compliance with biodiversity protection measures, in line with the EU's climate resilience and environmental sustainability goals.