Hi Ugo,

Thanks for a great post. Any sense of how many acres of solar cells would be needed to desalinate the water to irrigate an acre of farm-land?

Dave

Energy inputs to desal are not clear cut because there are issues like the salinity of input water, the distance input water needs to be pumped and hypersaline output water needs to be removed. In desert areas solar or waste heat (eg nuke) can be used to pre-warm evaporation cells and costs can be recovered from salt harvesting. For nondesert areas windpower can supply electricity to drive pumps required for higher capital cost reverse osmosis. These have to be weighed up against costs of the alternative to desal of partial sewage treatment to irrigation standards. Water charges seem to be around 50c to $1 per kilolitre but even that could be artificially low. Affordable for making tea but very expensive for farming.

Ugo

So, the question of a sustainable supply of water from the arid countries of North Africa and Middle East cannot be ignored any longer. Indeed, the deserts of the region provide plenty of well sun irradiated areas that can be exploited for energy production that, in turn, can be used for the production of water.

Fantastic post. Bring a WHOLE other dimension into view.

We are sooooo scroomed.

Hi all, lurker for a while. I'm a chemical engineer for the pulp and paper industry in the U.S.

I don't no why you'd ever use photovaltaic for this application. Where you only have a 14-30% electrical generating efficiency.

I rather use solar thermal multi effect evaporation. A 7 effect multi effect evaporator gets about 5.6 steam economy meaning, you can evaporate 5.6 lbs of water for every lb steam you generate. Further you'd only need low pressure steam generated. Low temperature steam say 5-6 bar is sufficient for multi effect evaporation. Since we are not trying to generate electricity high temperatures 400-600 C are not needed for high generating efficiency and thus this simplifies the solar thermal plant.

Water is solely a capital cost problem in Saudi Arabia. They have plenty of sun and access to sea water. And with current oil prices they have plenty of money. Further the intermittance of the solar is not a problem. This is not an electrical storing problem as it is for other solar thermal generating schemes. This is a water storing problem. Just desalinate large amounts of water during daylight hours and store during nighttime. Or if you want better return on investment on you ME evaporation plant use solar thermal steam generation during the daytime and then switch fossil at night.

The good news: They plan to keep exporting oil so they can eat.

What has happened to these poor folks? They have traded their most valuable resources for paper.

I think some of the figures may be overstated, but they are still in the ball park. I lived on a yacht for 2 years and designed, installed and maintained our on board desalinator. Now I work for Degremont - Suez, probably the leading Reverse Osmosis (RO) technology company in the world today.

On my yacht the desalinator produced 60 litres fresh water per hour from 10 Amps running at 24V. This is equivalent to 4 KwH per cubic metre. It is also small and very inefficient. The system pumped about 10 litres of sea water per minute with a 10% recovery.

By contrast our best practice RO plants (above 100k cubic metres per day) utilize "energy recovery" technology and are producing water at approximately 1KwH per cubic metre. These are multistage RO plants with recovery at about 50%. Power consumption is also improving, although a minimum will be reached.

Much of the Saudi desalination is done using using thermal technology and the waste heat from electricity generation. Degremont does not use this technology so I cannot comment on the metrics and what the true split is between power and water generation.

I think solar power would be a very good option of KSA. They have a ridiculous amount of empty, sun-baked land that would have tremendous potential. To extrapolate, I think the entire N.Africa/ME region can transition from being the world's provider of oil to the world's provider of solar energy. This excess electricity can be exported to Europe and Asia via transmission lines. In the process, this would free up natural gas currently used for power generation.

In your picture, there appear to be around 50 of these circles.
About a year ago, I was looking at google earth at Saudi Arabia and these are scattered around several different places.
From the areas I was scanning, there were in the range of several hundred of them, stretched out over a long narrow area.
It looked like they were built along a major river, although it might be an underground aquifer that you describe.
I suspected some type of agriculture, but could not tell for sure.
What really baffles me is - why are all of these in almost perfect circles and do not use the whole square ??

.

DocScience
http://www.angelfire.com/in/Gilbert1/tt.html

I think this is a fantastic post and very well thought out. If Saudi put in the investment, it could become the solar power hot-bed for the 21rst century. It has huge solar resources both for PV and CSP/Thermal. You can also store CSP using heat storage in molten salt chambers.

Is the following sentence from this article really a sentence?

These news come as a surprise, but not so much.

It's hard to make out what that means exactly, but the greater point is; I thought all the concern was about peak oil in Saudia Arabia, not water. The land cannot maintain their population of 120 million people after the influx of money from the oil depletes, so peak water will probably only play a secondary role in that country's demise.

I believe that a better solution would be a combination of hydroponics in greenhouses and solar CSP, wind and PV to power desalination plants.
In hydroponics, water consumption is one fifth to one tenth of conventional irrigated agriculture, and especialy in SA where evaporation is extremely high, gains would be even better - essentialy the only water that gets consumed is about 50% of total plant + produce mass.

The idea can work, but only if implementation starts soon enough; before the decline of oil production makes the costs involved impossible to bear.

Plus, "and before the decline of oil production limits the availability of fuels needed to implement these large scale projects."

Thanks for this post. This is another example that we can straight away deduct x million barrels of Saudi and other ME countries' oil production from what will be available on the world market. Westexas should take note and adjust his local consumption growth rates upwards accordingly.

Solar desalination is the desalination of water using solar energy. Renewable energy overcomes the usually high energy operating costs as well as greenhouse emissions of conventional reverse osmosis. Reverse Osmosis is currently the favoured technology for desalination, being the most cost-effective. Recently, there is evidence of growing research interest in the field. This is prompted by growing energy costs, demand growth in the face of depleted water stores, and the growing human pollution of many communities' water supplies.

http://www.global-greenhouse-warming.com/solar-desalination.html

All these construction projects require diesel and other forms of energy which we are now gobbling up for mere consumption. We need to set aside oil and gas fields as energy input for these particular project purposes.

Actually, I found quite an interesting article about Saudi investment in various forms of solar energy. It looks like it appeared in the "Saudi Aramco World" online magazine.

It contained the following thought-provoking sentence:

"Though the kingdom will neither need nor benefit from solar energy for decades, it is committing vast sums to its development now while there is still time"

How many other governments are making investments "while there is still time"?

This might be a stupid question, but why not use solar energy directly to evaporate/condense fresh water from sea water? If they started a slow program to steadily build greenhouse-like structures they could have quite a capacity in a few years.

Yes?.. No?...

"KSA Plan B":

1. With all the oil revenue invest in a large scale role out of advanced Thin Film PV manufacturing capability. $2/Watt costs would see the above mentioned Wattage for $60 Billion -pocket money...
2. Use 1/4 to power desalanation, 1/4 to beef up the grid and the rest can be exported.
3. Deploy PV arrays over dessert areas -unlike the nuke option these represent a low threat from terrorism, worst case the terrorist blow up a couple of square kilometres before being gunned down by the overhead AC130...
4. Aquaponics setup (fish and Hydroponics): ultra low water usage and good source of locally produced protein and fresh veg. KSA could even become a NET exporter to the region. The Nile Tilapia as its name suggests comes from just over the road so to speak.

Main Advantages:

1. Frees up oil and gas for Export at increasingly outrages prices
2. KSA has a key industry for the new world order and could become a leader in the Permaculture field
3. Enables sustainainable economic and population growth
4. Limits threat from terrorism
5. Decreases ELM effects -enables KSA to subsidize Hybrid/Electric transport policy@Home once its clear the world has a problem...

Given a fair wind and no key resource constraints the world could roll out 20TW of PV capability in 10 years if each of the top 50 countries invested in 100 TF PV plants each.

Regards, Nick.

During the 1960s in the US there was a tremendous amount of government-sponsored research being done on desalination, no doubt based on the presumption that there would always be cheap and abundant energy. At the time, LBJ had visions of turning the deserts of the Southwest into prime agricultural land.

One scheme that garnered a great deal of interest at the time was the concept of nuclear-powered desalination plants that both generated electricity and supplied heat for huge multi-effect evaporators. Needless to say, this concept never got off the ground, but I wonder whether nuclear-powered desalination wouldn't make sense for Saudi Arabia or the Middle East in general. While the US in particular would have concerns over nuclear proliferation, the bottom line is that every fossil fuel BTU that isn't spent on desalination is a fossil fuel BTU potentially available for export.

Taking 10 dollars/kW, approximately the present value, we obtain a round number of 300 billion dollars of solar panels.

Please tell me where I can buy 1000 watts of power generating solar cells for $10. Last I heard the cost of silicon cells was $4 PER WATT and nanosolar is talking about $1 per watt for their thin film stuff.

That $300 billion becomes $30 trillion assuming the best case estimate of $100/KW (nanosolar).

Thanks for the post.

This is about a group of scientists who wanted to work on desalinization in the 70s-they have now turned to using salty water to grow plants that animals will eat. Projects in east Africa and Sonora Mexico. They have interesting system of fish farming as well as goat and camel foods that provide meat and milk...They looked for and developed plants that can grow in salty soils.

The Seawater Foundation
Dedicated to greening the desert coastlines of the world to generate wealth in poverty stricken areas, eliminate famine, and improve the global environment ...
www.seawaterfoundation.org

Other comment is about nuclear in Saudi Arabia-How can they cool plants? I see that US southern plants will face water shortages. I recall last summers closing of one TVA plant as the, I think Tenn. River, was 94 degrees and too hot to cool anything...

I note that all comments gravitate to the energy and production side of the desalination process - understandably, but I remember reading that for all beneficial processes there is often an unintended downside.

As a result of the water with increased salinity being returned to the sea they are starting to find that the raised salt content and in some cases the warmer temperatures is having a detrimental effect on sea life, which exists within fairly narrow salinity ranges.

http://www.xpress4me.com/news/uae/dubai/20003208.html

" At a lecture given to the Dubai Natural History Group, Burt explained that while the remaining reefs in the Gulf survive under extreme conditions, the sea is just getting warmer and saltier -– with high amounts of chlorine -- due to increased rate of desalination.

Dozens of big desalination that dot the Gulf pump millions of gallons of warm seawater with higher and higher amounts of salt content back to the sea daily.

“Salinity here can reach 50 points per thousand (35 ppt is typical), which can be fatal to coral. In addition, water temperature in this area can range by 25 degrees Celsius. "

I am really interested in this topic. I searched for this location at the given coordinates on Google maps (26 degs 51' N and 49 degs 41' E) and was unable to find this square.

Please look at my link to this above coordinate to see what I mean.

I use Google maps internal Javascript to extract the coordinates of any point in my tool IslandMap.co.uk

Libya, for instance, is at present working at a project named "The Great Man-made River" (Water-technology, 2008) which aims at extracting the resources of fossil water of the Sahara desert.

I remember watching a documentary about the GMMR project a few years ago and if memory serves me it was said that the water was supposed to last about 30 years (don't know anymore if this was the supposedly overstatet official number or the more realistic one).
Apparently they collect the water in vast open pools leading to huge losses due to evaporation.
And further it seems that the depletion of the water reservoir is already causing a water level decline in oases and wells throughout the desert.

Overall the documentary gave the impression that the whole project was overly expensive, heavily fraught with problems and had a lot to do with prestige.
So in the end, I dare to say, they'll likely be worse off than before.

Just a question for our "interesting times".
What happens if terrorists who want to attack the present government of SA take out the desalinazation plants? How well protected are these plants compared to the protection afforded to the oil fields/processing facilities?

Thank you for your fascinating and well-researched paper! It shows how few options there really are for any of us, besides finding our way out of dependence on fossil fuels and fossil water!

Thanks for the interesting post. What I found astonishing is that according to the Renewable Fuels Association website in 2004 they were the worlds 9th largest ethanol producer . In 2006 they still were producing more ethanol than Australia. Presumably they have been using some of that precious fossil water to make fuel!

Interesting stuff. Just wondering whether anyone has considered less 'technical' solutions. For example, if they have access to large amounts of sea water then why not develop crops that tolerate it rather than expending so much effort in desalinisation? There must be all sorts of seaweeds etc. that could be farmed either for human consumption or as animal feed. Are there any plants that can grow in sea water and then be processed to extract fresh water?

[Edit] Just found this link: Saline Agriculture so it's not such a mad idea

I haven't any reference to hand but isn't there a problem with the plastic greenhouses of Almeria Andalucia ? The underground aquifer that is tapped to irrigate them has a finite life.

Apparently the twin problems in that region and Israel are labour and water and becoming the two major problems.

Good article ... one odd item to add , Mr Maktoum has plane loads of growing grass flown in from the UK to Dubai everyday to feed his racehorses.