Salt water, sunlight turn deserts fertile

After its first year of production in 2013, the Qatar site is already showing it can potentially fill the country’s cucumber import demand with just eight hectares of land.

These oases in the desert are part of the Sahara Forest Project, one of the few bright spots to have emerged from the otherwise failed 2009 United Nations Climate Change Conference in Copenhagen.

Its focus is to overcome the challenge of developing radical increases in resource efficiency, creating closed loop production models and developing a solar economy.

“There was an enormous amount of people there (at Copenhagen) telling how bad everything was going to be and we were there presenting a solution,” said Sahara Forest Project’s chief executive officer Joakim Hauge.

“While the climate negotiations ended badly, the Sahara Forest Project concept stood out to some in the room.

“So we started building on that and formally established the Sahara Forest Project both as a foundation in 2010 and as a company in 2011.”

The Norwegian-based Mr Hauge, who has an academic background as a biologist and broad experience on issues related to innovation and green technologies, teamed up with international experts such as the director of sustainable engineering firm in the UK Max Fordham LLP, Bill Watts (the project’s technology manager), and Michael Pawlyn of

Exploration Architecture who was one of the designers of UK’s Eden Project (now the project’s design manager).

Watts, Pawlyn and the Norwegian non-governmental organisation, Bellona, are the main shareholders in Sahara Forest Project.

Five years on and the one-hectare Qatar pilot project has had its first harvest and the building of a 20ha commercial demonstration site in Jordan is well underway.

Mr Hauge said the concept was designed to produce food, energy, and water in arid areas, and used sunlight and sea water to drive the system.

“Our ambition is to establish ourselves in low-lying desert areas across the world,” he said.

“The Sahara Forest Project is looking to take what we have on offer like sunlight, CO2 and salt water to produce what we need more of: sustainably produced food, water and

renewable energy.”

Among the mix of crops will be cucumbers, vegetables, desert plants and halaphytic plants, all of which are already growing in Qatar.

By establishing a commercially viable way to bring salt water into the desert, Sahara Forest Project works as an enabling technology, creating opportunities for a wide range of businesses to develop alongside it.

These include salt extraction, traditional desalination, algae production, halophyte cultivation, photovoltaics, mariculture, and bioenergy.

The main technologies used in the project include seawater-cooled greenhouses, solar power, and technologies for the revegetation of desert areas.

They are all based on the use of seawater.

“If we take seawater into a desert area, we would use it in a greenhouse (first) and pour that seawater over honeycombed cardboard pads,” Mr Hauge said.

“When the desert air blows through that wall, parts of the fresh water in the sea water will evaporate, causing the air to become cooler (ie. Evaporative air conditioning).”

“So that first purpose we use the seawater for is to cool and humidify the air inside the greenhouse.”

By cooling and humidifying the greenhouse air they immediately reduce the overall amount of water they need to apply to the crops inside.

“This greenhouse also has technologies for condensing part of this humidity in the air, in the greenhouse roof at night, so we can use that for irrigation,” he said.

This condensed water doesn’t meet all the greenhouse’s irrigation needs, but it goes a long way towards it.

To fill the gap, more fresh water is separated using energy from solar generation, and the salt water is in turn used to cool the solar power generators.

After being used in the greenhouse, the water is used outside to extend the productive area.

By flowing through cardboard evaporative “hedges” it cools and humidifies the surrounding air using the same evaporative principals as in the greenhouse.

The outside evaporative hedges also provide shelter from the wind, creating conditions for the cultivation of a variety of plants along the sheltered rows in between.

These crops, grown around the outside of the greenhouse, stabilise the soil and reduce the amount of dust in the air.

This improves the efficiency of the solar power generation.

Mr Hauge said the facility in Qatar had been developed in partnership with two of the world’s largest fertiliser companies, Yara International and Qatar Fertiliser Company.

“Their knowledge of crop nutrition has been very valuable for us in doing these pilot operations,” he said.

The main crop used in the Qatar pilot phase has been cucumbers, because it provided them with several harvests a year.

Mr Hauge said it was also a common crop which meant it had plenty of comparitive data against which they could benchmark their performance.

“Outside we’ve been cultivating about 19 different plant species, ranging from barley and rocket (rucola) and halophytes (salt-tolerant plant species) to more traditional desert species,” he said.

“There are a number of desert species that have very interesting potential... they have often been cultivated in the past, but many of these species have been forgotten.

“There will be species, for instance, for future fuel production, for making animal feed or for other purposes.”

The project, however, is yet to reach a stage where the growing of crops like barley has been done on a commercial scale.

But the results from the cucumbers showed this system already produced yields that compared favourably with those achieved in leading European greenhouses – current yields show three crops a year will produce at least 75kg/m2, and significantly higher yields can be achieved in a commercial set-up).

“It is estimated now it would take eight hectares of these greenhouses to cover all the cucumbers that Qatar imports annually,” he said.

Mr Hauge expected these systems had the potential to meet the country’s tomato import demand, with 40ha of greenhouse production.

But the benefits extend beyond just food production.

In areas in Jordan where the soils have been damaged from poor grazing management, he said this system could play a role in the reestablishment of vegetation.

“More and more it is perceived that political stability will be achieved through food security, water security and energy security,” he said.

“In a world where we need to increase our agricultural production by 70pc by 2050, it’s very clear we need to enable these kinds of countries to produce more of their own food.

“The positive ramifications of this project are part of the motivation for doing it, while we all believe it has a good commercial production capacity.”

Once the Jordan site is complete, it will be used as a test and demonstration centre to show the commercial potential of the technologies.

“But also as a centre for innovation in arid agriculture and energy production,” Mr Hauge said.