Case study ABU DHABI // Masdar, the emirate's clean-energy company, is to build the UAE's first large-scale water desalination plant to be powered by renewable energy.
The company is looking for technology partners for three trial projects to run until the end of 2015, before construction on the plant begins the year after.
"The aim of the pilot programmes is by 2020 to have a large-scale, commercially viable water desalination plant powered by renewable energy - whether it is solar, geothermal or other sources, or maybe even a combination," said Dr Sultan Al Jaber, the company's chief executive.
The UAE relies on desalination plants for more than 90 per cent of its potable water. In 2011, Abu Dhabi's desalination plants produced more than 2,700 million litres of water.
Like the rest of the country, Abu Dhabi relies on combined-cycle electricity and water plants, powered by natural gas, which are responsible for almost a third of the UAE's greenhouse gas emissions.
"Energy-intensive water desalination will continue to play its role, yet we have to start thinking about innovative ways of utilising technologies that will allow us to harness natural resources, like solar, wind, geothermal, to desalinate water," Dr Al Jaber said at the World Future Energy Summit, which concluded yesterday.
Masdar says it will cover half of the cost of the plant and its partners will cover the other half, but no figure has been announced.
Forty-eight companies have already been shortlisted for the programme and their ideas will be evaluated by a technical committee of experts from Masdar, UAE University, the Environment Agency - Abu Dhabi and the Abu Dhabi Water and Electricity Authority.
A second committee is evaluating the commercial aspects of the project.
The scheme will test innovative desalination technologies that have a smaller energy footprint, said Dr Corrado Sommariva, the president of the International Desalination Association. IDA, which is collaborating with Masdar on the project, is a non-profit organisation representing the industry.
"The desalination energy footprint at the moment is so high," Dr Sommariva said. "We calculated yesterday it would take anything between 50 and 200 square metres of solar panels to power one cubic metre of desalination per day.
"The emphasis is not on the coupling of desalination with renewable power, the emphasis is on new desalination technologies that have low energy footprints so they can easily be powered by renewable energy.
"There are a lot of good ideas on the market but these ideas have never been given the chance to compete because the state of the art is so well established."
Technologies that could be considered include forward osmosis, which uses semi-permeable membranes to filter salts and impurities from water, and low-temperature distillation, which like current technologies relies on thermal processes to distill water, but requires lower temperatures and thus less energy.
Leon Awerbuch, co-chair of the IDA energy task torce committee and interim dean of the IDA Desalination Academy, said one issue to be tackled was that renewable energy sources were intermittent.
And Mr Awerbuch said that in the case of solar, where sunlight is harnessed by photovoltaic panels, the best sites to produce energy are inland.
"Ultimately, you need to remember that sea-water desalination takes place on the sea and solar energy typically is in the desert," he said.
"Coupling is still going to be essential."

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