Global energy demand will threaten water resources
Paris, Reuters 21/03/2014
Growing energy needs will increasingly threaten the world's water resources and this phenomenon will be aggravated by the consequences of climate change, according to a Unesco report published on Friday.
Energy demand, the world's second largest source of water consumption, will grow by a third by 2035, experts from the United Nations Educational, Scientific and Cultural Organization Paris.
"Electricity is going to account for the biggest chunk of the increase in this energy demand and 90% of electricity production is water hungry," said report author Richard Connor during a meeting with journalists.
Thermal power plants, which generate electricity from gas or coal, or even nuclear power plants, use water to power their cooling system.
"These installations pose a problem of mobilizing the resource but they then take and reject the water, this is called open loops", tempers Richard Connor.
"In some European countries and the United States, thermal power plants account for nearly or more than half of all water withdrawals, or even more than agriculture," he adds, citing by example Denmark.
But "closed loop" systems, which take less water but do not release it into nature, are particularly likely to develop in the coming years, underlines the report.
NO MIRACLE ENERGY
At the same time, climate change will in the coming decades increase the phenomenon of water stress in certain regions, such as Central Asia, where energy needs are exploding under the effect of growth.
"Drought threatens hydraulics in several countries and, conversely, the availability of water could be a constraint to the expansion of electricity in several countries with emerging economies," he said.
To meet these challenges, Unesco believes that countries must develop the most water-efficient renewable energies, combine electricity production and water service sites such as desalination plants, or even use salt or waste water for cooling.
"But no energy is a miracle solution", admits the author of the report, especially with regard to large hydraulic dams, reliable energy that can produce a lot and without carbon impact, but whose social and environmental impact can be high .
Hydropower, however, retains great potential on the planet, particularly in regions most affected by the "economic scarcity" of water, says Richard Connor. A phenomenon very present in sub-Saharan Africa, where the resource exists but where populations have little access to it due to the lack of infrastructure.
Energy represents about 15% of the water used in the world, behind agriculture, crushing the first consumer who totals 70%. Domestic use represents only 10% of this consumption.
http://www.boursorama.com/actualites/la ... cf130e2fcc