Desalination: saviour or sinner?

We were delighted recently to read that the world’s largest seawater desalination plant has just begun operation in Hadera, Israel. According to WaterLink International’s news story it’s ‘part of a desalination master plan to help address the chronic water resource problems in this region‘. In the words of Dow Water & Process Solutions’ general manager:

The successful operation of this plant in one of the most water-challenged areas of the world speaks to the bright future seawater reverse osmosis technology has in addressing the needs of regions, that are facing growing demand and limited availability of freshwater resources.

The Hadera plant was opened by Israel’s President, Shimon Peres, on 26 May. The plant is situated about 25 km North of Tel Aviv, directly on the Mediterranean. The installation is vast by any standards and overall can supply 275,000m³/day or about 1 million m³/annum of fresh water. The WaterLink post states the plant is designed to deliver ‘about 20% of Israel’s domestic potable water requirement‘. (With its full compliment of 53,000 Dow Filmtec Reverse Osmosis elements, its membrane compliment theoretically could deliver 456,000m³/day.)

Investment to date has been $463 million (USD). It’s expected the plant will supply water at a cost of $0.57/m³. This figure is surprising. It’s about half that of other extremely efficient seawater desalination plants in other parts of the world. Perhaps the figure is more about political need rather than technology though. It relates quite closely to the alternatives – i.e. the costs to pump water from the Sea of Galilee to Tel Aviv or else to buy it by the tanker load from Turkey.

To achieve this output – even with what is being hailed as a highly energy efficient plant – will however require 450 Gigawatt of electricity per annum. (As a rough guide, to produce one cubic metre of freshwater from seawater by reverse osmosis requires about six Kilowatt hours of electricity.) What this will do to carbon emissions from the region – particularly when Israel talks about seawater desalination eventually delivering up to 27 times the output of this one plant – is a very moot point indeed.

Now, looking at the plant’s planned delivery of 20% of Israel’s potable water requirement – designed to help quench the country’s ever increasing desire for water – reveals other potential problems for the future. True, Israel recycles more of its water than any other advanced country in the world. However its does correspondingly little to restrict its people’s lifestyles by accepting that it resides in a region with such limited water.

Moreover, agricultural needs for water in Israel far outweigh potable use. It seems astonishing that Israel – which has fought so hard for its water – is at the same time squandering it by exporting ‘virtual water’ (a concept we’ve touched upon previously). It has been suggested that Israel is using about two thirds of its water on irrigation for its agricultural industry. Early in the development of the State of Israel this was very important. Now it represents around only 2% of the country’s GDP. So exporting virtual water in the form of oranges and tomatoes seems quite ridiculous. (Fred Pearce touches on this issue in his book, When the Rivers Run Dry.)

Let’s hope we can look forward in the future to Israel taking a more integrated and logical approach to meeting its increasing water needs. Rather than constructing large ‘cathedral type’, power-hungry, high-cost desalination facilities – or stealing water from its neighbours – perhaps it should investigate a little more closely where and how its hard-won water is actually used.

Update (15/11/2016): Public domain feature image added from this source.

Roger Ford

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