Influence of state support on water desalination in Spain

Water desalination has been supported since 1983 by the Spanish Government to obtain a price of drinking water similar to the average price of water used by households in all of Spain. The support was calculated according to many factors such as the cost of water production (i m!3), energy consumption (kWh m!3), quantity of desalinated introduced in the supply network (m3 y!1), and population density (inh km!2) from 1983 to 1996. In 1997, according to advances in the economics system undertaken by the Spanish Government, the formula was simplified to take into account only water production and management. In regions with strong water scarcity such as the Canary Islands, subvention for water desalination was calculated following the hydraulic system efficiency of each concession company. Since 1997, the difference of water market prices between the Canary Islands and the rest of Spain has been practically constant at 0.87 i m!3. The water desalination industry has had a sustainable growth due to price controls in Spain.

In spite of the advances in the marketing, the differences in water prices are not related to water marketing in Spain. Some factors have a significant influence in darkening the effect of the open market on water prices. The main factor that influences water price is the policy of intervention, which bears in mind water scarcity in relation to different uses of water. Water does not have a price according to its quality and availability. The same waters have different prices in different regions according to their use for either drinking water, urban use, industrial use, agricultural use, or environmental use. Since 1983 the Spanish Government has been supporting water desalination to obtain a price of drinking water similar to the average price of water used by households. The formula used to calculate water subvention considered many factors such as water prices due to water scarcity and desalting water costs (i m!3), energy consumption (kWh m!3), efficiency of the hydraulic system to avoid water losses from the supply network, fraction of desalinated water vs. natural water introduced in the supply network (m3), and population density (inh km2). Nevertheless, according to advances in the marketing system undertaken by the Spanish Government since 1997, the formula was simplified to avoid factors other than water production and management. This subvention has given sustainability to the water desalination industry. The installed water desalination capacity in Spain in 2001 surpassed 0.21 km3 y!1, of which 70% was produced by RO because of the improvements in membrane technologies, 23% by MSF– MED, 5% by VC, and 2% by ED. Nowadays, the quantity of desalinated water is near 300,000 m3/ d!1, which supposes 2.6% of total water used by households. The White Book of Water in Spain foresees a water desalination capacity of 0.412 km3 y!1 and a volume of desalted water nearly 800,000 m3/d!1 in the mean-term. This forecast takes into account a sequence of urban use and agriculture reuse that make possible to increase the utilisation level from the actual 54% to the future 70%.