The country's first desalination plant that works on renewable energy has been inaugurated in Abu Dhabi, the capital of UAE. Though the plant can produce just a modest 1,500 cubic metres of water per day - enough to supply 500 homes - the possibilities are endless.

As per  Abu Dhabi's renewable energy company Masdar,  the idea is not to add more desalinated water to the existing 916 million imperial gallons produced daily in Abu Dhabi. The whole purpose of the plant is commercialisation, to prove to investors  that renewable energy-powered desalination plants are bankable.

The project is part of Masdar's renewable energy desalination programme launched in 2013 and funded by the Abu Dhabi government. The project began  in 2013, when Masdar invited 180 companies in the water desalination industry to participate in the pilot project. Based on their sustainable and energy-efficient technologies, Masdar chose four international partners to build four plants - Abengoa (Spain), Suez Environment (France), Veolia (France) and Trevi Systems (US).

All four plants now operational are located on the site of a decommissioned desalination plant with access to deep seawater. The chosen site was a decommissioned desalination plant in the Ghantoot area, selected due to its accessibility to deep seawater and availability of electricity and natural gas.

Like with any desalination plant, the Ghantoot pilot plant starts by extracting seawater. This is pumped into a tank, where it is tested to verify the quality. It is then distributed to the four partners, each receiving a water flow varying from 10 cubic metres to over 100 cubic metres per hour, based on each partner's requirements.

Three of the plants use reverse osmosis technologies, and one (Trevi Systems), forward osmosis.  Reverse osmosis removes seawater by pushing seawater through a membrane filter while forward osmosis works in reverse by pulling seawater through the membrane to produce fresh water. 

Latest membrane developments coupled with solar energy power could produce 10 to 20 per cent more fresh water at the test plants.

All four plants use various technologies to save as much energy as possible.  

As part of an 18-month renewable energy desalination regimen, three reverse osmosis plants and a single forward osmosis plant will aim to reduce potable water production costs by 40 per cent.

Energy consumption aside, one of the major environmental issues with desalination plants is the brine, the leftover salt from the extracted water, which is usually dumped back into the sea, thus increasing salinity and harming corals and marine life.

The four plants discharge a total of 3,951 cubic metres of brine back into the sea daily as per the guidelines/regulations of  the Environment Agency - Abu Dhabi. As per regulations,  brine should be discharged a few metres  into the sea .

All desalinated water produced by the four plants is collected in another tank and checked daily by Masdar to ensure it is up to quality standards.

Global water consumption doubles every 20 years - more than twice the rate of population growth. This is one of the world's most pressing issues, both economically and socially, and is especially critical in arid regions.

The water demand in the UAE is expected to grow by 30 per cent by 2030 and most of it comes from desalination plants. "The UAE has the highest rate of water consumption in the world and 80 per cent of it comes from desalination plants. Yet, it is 10 times more expensive to produce water from desalination than from ground surface - so desalination is not sustainable.

If the renewable energy desalination pilot plant in Ghantoot, which works mostly on solar power, proves to be commercially successful, it may be the answer to water scarcity not only in Abu Dhabi, but also the region and beyond.

Masdar has given itself one year to demonstrate that this is a good investment.

Developing innovative technologies that can sustainably source clean water is vital, not only for the UAE, but for the Gulf and many other regions of the world. With this programme, the UAE is actively and responsibly addressing the challenges of water conservation, management and security.

As much as 98 per cent of potable water is produced in the UAE by desalination, an energy-intensive process where seawater is drawn through membranes to filter out brine.

The new pilot project's four test desalination plants will produce roughly 1,500 cubic metres per day, in addition to the 916 million imperial gallons that flow through existing desalination plants every day in Abu Dhabi.

• In the UAE, seawater desalination requires ten times more energy than surface fresh water production and demand for fresh water is projected to grow by 30 per cent in the UAE by 2030

• An estimated annual cost savings of $94 million (Dh345.28 million) is expected from 2020 onwards, if 15 per cent of Abu Dhabi's newly built desalination capacity is met by the implementation of the demonstrated energy efficient technologies

• It takes roughly two litres of seawater to produce one litre of fresh water

• The average home uses one cubic metre of water per day

• The Gulf region accounts for around 40 per cent of the world's desalinated water production.

 

This project is an achievement in itself and speaks of UAE's commitments towards sustainable development as it :

a.       Is an investment in new technology and, an opportunity to test & deploy it

b.      Is a means to solve region's water scarcity issue

c.       Means to reduce carbon footprint

d.      Means to reduce water production cost.

 

 

Sources:

Masdar  

Gulf News  

Khaleej Times