Wednesday, 29 May 2013

THE Desert Kingdom; desalination from oil power to solar power?
15 Apr 2013

Saudi Arabia finds itself in an interesting economic cleft stick. While blessed with oil that it can currently sell at around $104 per barrel on the world market, it is compelled to burn a sizable proportion of that potential income to produce desalinated water. Cost of production of water fluctuates, but a fair guess is between 40 and 90¢ a barrel, depending on fuel price.

To produce water, the Kingdom uses approximately 1.5 million barrels of oil a day across its 30 or so desalination plants to meet the demand for domestic and industrial water. Little of this water--if any is used for agriculture. The water for agriculture--some 85 to 90% of the total water use in the Kingdom--comes from non-replaceable resources, underground aquifers that are drying out rapidly. For every 100 liters per annum withdrawn, only one liter or less finds itself back into the aquifer.

The government has wisely decided that food security, once an unquestionable shibboleth of policy, is no longer worth the use of resources and has taken up the idea of virtual water. This refers to the hidden flow of water if food or other commodities are traded from one place to another.

Virtual water is best defined as "the volume of freshwater used to produce the product, measured at the place where the product was actually produced". It refers to the sum of the water use in the various steps of the production chain. It is 'virtual' for when the product arrives at its destination, the water is no longer contained in it, and was used only to produce it. An example of the saving of such imports is wheat, which takes 1,600 tons of water on average to produce one ton of grain.

It has resolved that the Kingdom will rely entirely on imports for food by 2016. Starting in 2008, the government has been reducing wheat purchases from local farmers by 12.5% a year and plans eventually to withdraw all agricultural subsidies to these farmers. Having addressed the issue of water supply and use and effectively engaged the biggest user of water, agriculture, positively, desalination for the balance of life in the Kingdom remains a huge challenge on several levels.

A major issue, the use of expensive oil that could produce income for making water, has spawned a slew of projects based on solar power for water production. The Kingdom might, and probably is, considering nuclear power as another option, but this introduces the political aspect of the importation of nuclear fuels and technology to the region, which is already under the baleful gaze of the West.

Happily, Saudi Arabia is one of the sunniest places on earth, averaging between 200 and 300 hours per month. Solar power therefore is an environmentally friendly, infinitely renewable (well, for the next seven billion years or so and the earth will have dried out and life gone in 3.5 billion) and very available alternative. Moreover it is harmless, both politically and environmentally.

The Kingdom seems to have opted so far for the expensive option of photovoltaic cell electricity generation to run the new solar desalination plants rather than the simpler, longer lasting and lower maintenance Concentrated Solar Power (CSP) alternative. Commercially viable CSP plants are already in operation in California, France and Spain--all with lower sunshine hours--and are feeding electricity into the grid.

The government is tackling the building of desalination capacity actively and has allocated $6.4 billion for water and sanitation projects in 2013.

Saline Water Conversion Corp. SWCC, (which supplies 50% of the municipal water in the Kingdom and produces 18% of the global total) for example plans to build the world's largest water desalination plant in Rabigh and will have the ability to pump 600,000 cubic meters of desalinated water per day. The conventionally fueled plant should be completed by 2018. State-owned National Water Co, plans to spend $66 billion on plants and upgrades over the next 10 years.

In October 2012, Abdul Rahman Al-Ibrahim, governor of SWCC announced plans to establish three new solar-powered desalination plants in Haqel, Dhuba and Farasan in addition to the one under construction in Khafji.

The Khafji solar desalination project will be the first large-scale solar-powered seawater reverse-osmosis (SWRO) plant in the world. It was due for completion at the end of 2012 and designed with a capacity of 30,000 cubic meters of water per day for the 100,000 customers.

The Khafji desal plant is the first step in King Abdullah City for Science and Technology's solar power program to reduce desalination costs. Phase two of the project is the construction of a new plant to produce 300,000 cubic meters of water per day is planned by 2015, and phase three will involve Haqel, Dhuba and Farasan by 2018.

The Kingdom is not alone in the search for a clean, effective and cheap means of producing water. The UN classifies around 700 million people in 43 countries as suffering from water scarcity today. By 2025 the figure is forecast to rise to 1.8 billion.

With the global population expected to reach nine billion by 2050 and the US secretary of state openly discussing the threat of water shortages leading to wars, the production of desalinated water has never been more important.