The Rain in Spain falls mainly ….
It was Easter 2001 and I was returning from Granada on an Easy Jet flight to Gatwick. I had been in Andalucia on a University field course and as I hadn’t particularly enjoyed the trip I separated myself from the main group prior to checking in. As a consequence I was at the rear of the flight, far from the party I had travelled with and sat next to an older man who introduced himself as James.
The plane took off and as it levelled out and banked slowly around to head north it revealed the ground below, acre after acre of white plastic sheeting, the horticultural industry of the Campo de Dalías where the endless Mediterranean sun provides a constant energy source to permit growing salads to the precise timetables of Europe’s supermarkets. What though struggled to keep up was the ground water, with over extraction to feed this industry leading to salination of the aquifer.
Andalucia produces some 30% of Europe’s salad crops but in doing so have started to reverse the hydrological flow resulting in seawater being sucked into the very aquifer they depend on. To make matters worse precipitation rates in Spain have been falling in recent years and whilst the effect on the Albedo of the industry has been to bring about localized cooling it has done so by increasing the intensity of rising thermals. This in turn has potentially impacted on the normal inward progression of rain clouds from the sea to the Sierra Nevada causing them to rise and prematurely shed their loads.
As the Campo de Dalías went out of view the conversation continued on its environmental theme as James explained that he was living in Tarfaya, a small fishing town at the southern tip of Morocco. He was to return after a brief visit to the UK when he hoped to promote a project; The Mauritania Forest Road. He claimed that the area between Tarfaya and Mauritania had once been forested and that Pliny the Elder had noted in the 1st century AD that Canarii, the Roman name for the area, was “a woody region abounding in elephants and serpents.” It had not always been a barren desert. We exchanged emails and 18 months later I found myself travelling overland to Tarfaya.
I had by that time lost contact with James but he had not only exchanged his own email but that of Shaibata Mrabihrabou, a resident and president of the friends of Tarfaya, a small self help group. I was at that time in central Portugal, visiting friends and following communication with Shaibata Mrabihrabou decided that with only 5 buses and a boat trip between Quimbra and Tarfaya, I should take the opportunity to visit.
The Friends of Tarfaya
It was early evening when the bus pulled over and the luggage ‘boy’ indicated that this was my stop. I stepped off and stared at the expanse of sand and sea as he retrieved my bag from the luggage compartment. As he passed my rucksack to me I asked “Tarfaya?”
To which he pointed at a small object in the distance. A walled town with a harbour Tarfaya was the closest point on the African continent to the South American, but it was also, at this point in my three day journey, the furthest point from the road. As the bus pulled away I shielded my eyes and waited for the dust to settle before looking up to see that a deserted petrol station had materialized on the opposite side of the road. It was surreal, a lonely building surrounded by rocks and sand illuminated by the setting sun. I stared at it briefly before turning to look at the sea and the sun as it sunk rapidly towards the Atlantic ocean.
Picking up my rucksack I begun walking in the direction I had been pointed in. The sun had almost set by the time I walked into the main high street where I was quickly accosted by a curious local. A small town of a few thousand inhabitants it was not long before I found myself at the home of the man I had come to see, Shaibata Mrabihrabou or Sadat as he preferred to be called. I spent just over a week with Sadat visiting Tarfaya and Laayonne where I made notes before returning back to Europe and whilst I remained in touch, James never resurfaced.
It would be three years though before I would return and then not to work on the forest road project but because I wanted to to write. The desert is an ideal place to isolate oneself away from distractions and whilst I did it rained. In fact it rained so heavily and continuously for the next six weeks that the wadi’s, the ephemeral rivers that barely saw a drop of water in a normal year, burst their banks and washed away the roads. Tarfaya became a lorry park as the south was cut from the north, but cocooned in my own world I barely noticed.
A Green Green Desert
As the water’s receded the once barren desert had filled with shallow ephemeral lakes that attracted passing flamingo’s. The dunes that formed their banks had turned a deep leafy green along with the desert itself which now resembled a prairie. It was as surreal as it was unexpected; an area the size of Texas, the edge of the World’s largest desert was preparing to bloom. I was though myself also preparing to leave so whilst I saw few flowers as I left S’mara, it was, if nothing else, a demonstration of the true potential of what lay hidden within the sand. A potential that needed only fresh water to be realised. It was though the last time I visited Tarfaya and soon after I lost touch with Sadat.
The Solar Village
In the summer of 2008 I began to explore a concept. I had seen a solar farm in India in 2005 that used solar collectors to heat water in order to cook for a hospital. The units were not only simple but extremely small given the number of meals that could be cooked. However using water as the medium to store the heat limited the temperature to 120 degrees C. Any higher and the water would change from a liquid to gas, generate pressure and run the risk of exploding. Similarly only water above a temperature of 60 degrees C was useful as once it dropped below 60 degrees C conditions become suitable for the growth of harmful bacteria. Thus the amount of usable energy that can later be extracted with water as the storage medium is a fraction of the amount of energy that could be collected by the array if another medium was used.
An alternative substrate with a higher boiling point would permit that temperature to rise to 500 degrees or more. This would not only allow for more energy to be captured but at 500 degrees the energy would be sufficient to drive a steam turbine and generate electricity. Heat can also be stored and then used to generate electricity during the night. Combined with accommodation the thermal updraft generated by the collector could provide negative pressure to both drive an air conditioning system and to seed the updraft with moisture laden air. Rising and cooling rapidly this moist air should facilitate the formation of low altitude clouds which both reflect solar radiation and aid localized precipitation. Self contained and producing more energy than required for the concept itself the surplus electricity could be sold or used to desalinate sea water and that water could be used to re-afforest the desert…
The idea that the West coast of Africa was once wooded and home to elephants and that this could be restored is not as far fetched as it may first seem. The Sahara was not always as large as it is today with large tracts along the mediterranean coast having being heavily wooded and capable of supporting larger populations than it does today. There are various theories as to what caused the decline of the forests and the subsequent expanse of the Sahara but most, and the most probable, involve an axe. It’s who precisely was wielding it that the arguments are usually over.
The Sahara Forest Project
With projects in Tunisia, Jordan and Qatar, The Sahara Forest Project, a private limited company sponsored by The Norwegian Ministry of Climate and Environment, the EU and others intends to create “a new environmental solution designed to utilize what we have enough of to produce what we need more of, using deserts, saltwater, sunlight and CO2 to produce food, water and clean energy.”
Ouarzazate Solar Power Station
East of the Atlas mountains set in the Sahara desert is Morocco’s NOOR project: Covering an area of 2500 ha-1 it is home to three of the World’s largest concentrated solar power units in the World. The culmination of six years work the plants, when they all come on line, will be capable of producing 580 MW of electricity, sufficient energy to power a million homes. The Noor facility uses two different arrays but both use a salt solution which can be heated to 400 degrees C. This heat is then used to generate steam to drive a turbine or stored to provide sufficient heat to maintain electricity generation for 8 hours of darkness.
Greening the Desert, with the Sea
The NOOR CSP plant at Ouarzazate demonstrate that it is technically feasible and cost effective to harness solar energy to generate carbon neutral power. The Sahara Forest Project has further demonstrated that it is possible to use this energy to desalinate water, grow trees, capture CO2 and reverse the effects of climate change. The cost of desalinating sea water with a modern plant is now 3.5kwh m3 of water produced. In Perth Western Australia this out put is achieved largely using renewable energy.
Thus a plant with the same 200MW power output of NOOR III could produce 57 million litres of water a day. Sufficient to irrigate 400 ha of agricultural land to a depth of 100ml water per week ;the equivalent to a mean annual precipitation of 500mm per year. Whilst insignificant in the 260,000 km2 expanse of desert that is Moroccan Sahara it is sufficient to create a forest oasis of a million or more trees covering an area of 2km2. Stretched out this forest could provide a shaded road from Tarfaya to Layonne (10% 0f the coast line).
The Mauritania Forest Road
It’s been fifteen years since I first heard of the Mauritania Forest Road project on an Easyjet flight from Granada; and in that time not a single tree has been planted in it’s name. That however doesn’t mean this project is a failure, on the contrary. It never really started and had it done so, without water it would have failed. The technology and the political will have still yet to be fully realised for such an ambitious concept to stand any chance of success; but as with all our environmental woes it is not an absence of solutions that holds us back, but more our refusal to adopt them.