Desalination

• Desalination is one of the only methods to increase freshwater availability.
• Removing salt from water is energy-intensive and expensive.

  • In the arid Middle East, the high cost means freshwater is only used for drinking and not for growing crops. Food is imported instead.
  • Developments in technology have reduced the energy demand by up to 75%.
  • If energy can be generated using renewable sources (solar) the process will release less greenhouse gases.
  • Some plants use heat energy left over from generating electricity in power plants.
• Producing 1L of freshwater generates 1.6L of salty brine. This waste product is pumped back to sea.

  • Most plants are built near the coast so cost of pumping is low.
  • The salty brine can cause hyper-salination which can damage sea grasses and fish larvae.
  • The salty brine reduces available oxygen.
  • The pumps for water intake/outake can harm large marine mammals.
• As the construction and operating of plants is expensive, low income countries miss out.

  • There are many low income countries (Yemen, Somalia) where water is a significant issue. This worsens inequalities, with desalination being out of reach for low income nations but extensively in high income countries (UAE, USA).
  • The cost of freshwater increases. Even within a country, this means that it can be bought by those on higher incomes.
  • Many low income countries with arid areas have access to abundant seawater to supply desalination in the future.
• Sustainable Development Goal No. 6

  Clean Water and Salination - The challenge of meeting the freshwater needs of an increasing population, whilst climate change causes widespread droughts.
• Reasons for Desalination

  • Increasing population, more demand for water in domestic settings.
  • The world is growing and making more in agriculture and industry.
  • Climate change is causing the rate of water replenishment to be unpredictable and higher global temperatures are causing droughts.