DESALINATION PLANTS IN CANARY ISLANDS Spain’s involvement with desalination spans several decades. This nation was the first European country to install a desalination plant in 1964, on the island of Lanzarote (2.300 m³/day) in the Canary Islands. In those years, the government saw an opportunity to boost economic activity through tourism to the sun‐drenched Canary Islands. Because of insufficient natural water there to make this vision a reality, a desalination plant was built to lay the groundwork for tourist‐related growth. The Canaries is a pioneer in the world in terms of the potabilization of sea water, as well as other techniques and strategies related to desalination. They represent an almost perfect model of reference in the field of seawater desalination. Starting from the 1960s many desalination plants have been built to provide fresh water from non‐conventional sources.
The technical evolution in seawater desalination since 1965 up to now is perfectly represented in the Canaries. From these early times until 1980 the scene of desalination is dominated by the processes. The constructed plants are dual, producing water and electricity. It was in Lanzarote island where the first seawater desalination plant with reverse osmosis membranes was installed, which meant a revolutionary technological change in the water sector as opened the
doors to the progress and development of the dry and arid Canary Islands. Until the mid 90s the seawater desalination in Spain was mainly located in the Canaries with plants of low or medium production capacity ( not more than 20.000 m³/d). 3
Today the desalination capacity is approximately 315.000 m /day, representing almost a 2 % of the world desalination capacity but only the 0.028% of the world population. This water coming from desalination plants supplies about 1 million people and almost all tourists visiting the islands. In the case of Lanzarote, the island that most strongly depends on desalination, nearly 99% of the consumed water comes from desalination plants.
Desalination has certainly contributed to the progress and development of the Canary Islands and has improved the population life quality, allowing a safe and continuous supply of water for domestic, agricultural and tourist consumption. Nevertheless this solution to water shortage has a major disadvantage: it is strongly dependent on the non‐renewable energy and, therefore, on the amount and price of it. New researching methods have long been carried out to reduce the energy consumption in the reverse osmosis membranes process. And scientists there are taking this one step further: they are investigating how to produce freshwater from saltwater without using fossil fuels at all. New energy recovery devices as the “Polton”
turbine, pressure exchange chambers,….etc have been installed in the last years.. Because of this situation, the Canary Islands have started a last struggle: the industrial production of drinking water from seawater using RES, mainly wind and solar energy. Desalination with RES offer an interesting possible solution in those places with wind and/or solar energy resources or any other renewable energy source and lack of fresh water supply: coastal (seawater) and continental (brackish water). And these kinds of systems are also the best way to provide water to areas isolated from the grid or to small islands (weak grid). The challenge, however, in coupling desalination directly with renewable energy such as solar or wind power lies in the variability of renewable energy. The membranes used in reverse osmosis need to be kept wet, and the systems that make up a desalination plant have been developed to handle a steady stream of water. Solar energy is plentiful when the sun shines and wind power only when the wind blows.
It is difficult to imagine how life in the Canary Islands would have been today without the extensive application of different desalination techniques. In the past, those islands that had almost no ground water resources were supplied with water by means of tank vessels from the Navy. It is probably true to say that neither the population nor the tourist sector and even agriculture would have gone so far today without desalination technologies.