Although the water desalination plants lining the coast of Spain, Water scarcity According to the experts Efe consulted, high operating costs in some regions and impacts on the marine environment make its use less sustainable than conserving water and raising awareness of its use.
According to data from Zinnae, an Aragonese cluster focused on the efficient use of water, There are a total of 765 desalination plants installed in Spain.It is mainly located in the Levantine region and island regions, although some have been “paralyzed as economically unfit”.
The reason for the high price is “Significant amounts of electricity are required to heat the water in the thermal power plant.Some methods that require around 4 kWh of energy to produce 1 cubic meter of desalinated seawater.
There are a total of 765 desalination plants in Spain, mainly in the Levantine region and on the islands.
In addition, reverse osmosis membranes, the most common desalination technology, if the use of the installation is not continuous, it will deterioratetherefore, “they cannot be operated according to the water demand due to the costs they will cause in terms of both energy and equipment”.
In addition to its high price, effects on marine ecosystemsSince desalination produces large amounts of salt water, it is a harmful byproduct for underwater life due to its high salinity.
Despite its drawbacks, desalination also thrives, especially in island environments that don’t have their own resources for supply, for example Gran Canaria, “the place with the most desalination plants per square kilometer in the world,” he explains. Engineering Industrialist, Emilio Custodio, from the Polytechnic University of Catalonia.
Boron problem in agriculture
However, urban supply is not the biggest obstacle, “The problem is in agriculture, which is a big consumer of water, which has a limit on how much it’s willing to pay for water.”In the case of a desalination plant that does not operate all year, a price that “can exceed 2 Euros per cubic meter, which is not suitable for many farmers”:
“Yes, you can irrigate with desalinated water, The problem is the boron content, which although drinkable, is too high for some products.”, so that farmers “mix with transfer water or aquifer”.
In fact, they point out from ZINNAE that “although only 3% of desalinated water is used for agriculture worldwide, this proportion reaches 23% in Spain”, but that increasing production to irrigate fields will “require huge energy needs for the world”. . Collection, treatment and management of brine, which requires high economic and environmental costs“.
Beyond the high energy consumption, Santiago Martín Barajas, coordinator of the water area of Ecologas en Acción, adds The salt water that “destroys the seagrasses of Posidonia”, because they cannot withstand “more than 42 grams of salt per liter”.
In addition to contributing to the loss of these valuable marine ecosystems, “the fact of having more water through desalination can increase consumption, which puts us in a more unsustainable situation,” he says.
Ecologists do not consider “continuous desalination as part of the supply system”, except on “islands where it is necessary”, such as the Canary Islands.
“We have more watering than we can afford” Recalling that this activity represents “85% of water consumption in Spain”, Martín Barajas said, therefore, it should not be irrigated with desalinated water, the surface should be reduced” because “desalination is the last resort to supply the population with drinks.
They point out from ZINNAE that to combat the scarcity of water resources, a radical change in the value placed on its use is needed, especially when compared to other resources, which is often underestimated because of its low cost. like energetic ones.
Well, “Saving water and raising awareness about its use is an important tool. addressing water scarcity”, “a problem that concerns all consumers: population, industry, tourism, trade and agriculture”.
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