3 made in Spain fog collectors capable of collecting up to 250l of water per m2 per month are presented

In an increasingly arid world, every drop of water counts. And where is there any water left that we humans are not using? One of the most poetic places to look for them is within the fog, clouds of tiny droplets in suspension that could give a second chance to the most degraded or thirsty environments in the Mediterranean. This has been the premise that has driven the LIFE Nieblas project, co-financed by the European Union, over the last four years and which has enabled the development of three innovative systems for capturing water from fog in a cheaper, more efficient and modular way, water that is useful for reforestation or for irrigating the most difficult places. After years of research and testing in the Canary Islands, its main partners, CREAF, GESPLAN, ICIA, ITC and the Cabildo de Gran Canaria, are today presenting part of their results at the Fundación Universitaria del Bages in Manresa at a conference that aims to begin to multiply the use of these systems throughout the Iberian Peninsula.

In total, three different systems have been developed with a variety of materials and technologies capable of capturing more than 500 litres of water per m² in 10 months in the installations carried out in the Canary Islands. By July 2023, 35,000 litres had been collected with a total of 27 collectors of different types, of the 215,000 litres that are to be collected during the entire project. More rudimentary but very efficient systems have also been developed to ensure that the tree plantations are successful and the scions survive the dry summers. All these innovations have the potential to be installed in other locations in Spain and Portugal, and the project is also studying their viability in Catalonia, especially in areas of the central Catalan plateau, the coastal mountain range and the Pre-Pyrenees.

The project has involved a multidisciplinary team of experts in the restoration of degraded areas, evaluation of soil regeneration processes, sensorisation of plantations, irrigation systems, meteorology and, of course, fog water collection systems, all working side by side with the landowners. CREAF is working together with the Universitat Autònoma de Barcelona, the Cabildo de Gran Canaria, the Canary Islands public company Gesplan, the Canary Islands Institute of Agricultural Research, the Canary Islands Technological Institute, the University of La Laguna, the Heredad de Aguas de Arucas and Firgas and the Intermunicipal Community of Viseu Dão Lafões in Portugal.

Inspired by nature

The leaves of Canary Island pine trees have a secret, and that is that they are designed for the same purpose, to trap droplets of fog. This naturalistic observation has inspired an idea within the LIFE Nieblas project that has given rise to the most efficient rain collector of all: the needle collector. The collector is easy to assemble, small and has crossbars from which identical metal fillets are hung on the needles of Canary Island pine trees. Fifteen structures (about 9m²) have proven to collect up to 525 litres per m² during the 10 months of testing in the Canary Islands. It was the most efficient and versatile design.

Two other models have also been tested, much larger than the innovative collector, namely the tower collectors, which have two different covers, the kiwi mesh and the volumetric mesh. Just one of the volumetric mesh type has managed to capture up to 379 litres per m².

"We are talking about systems that have already been tested, they are not prototypes, but structures that are ready to go on the market and be used in areas where the fog and wind conditions are met," says Vicenç Carabassa.

Finally, by chance, the project has tested a much more rudimentary model of collector that can be used both in reforestations and agricultural plantations. This is the individual collector, a rigid tubular structure that surrounds the small planted trees to protect them from goats or other herbivores. This structure, when covered with the same kiwi netting as the tower collectors, is able to trap water from fog while maintaining humidity and preventing predation of the shoots by goats or other herbivores.

“Until now, these restorations have been irrigated by tanker trucks, or even helicopters, at a cost of up to €260 per live tree after two years.”.

GUSTAVO VIERA RUÍZ, GESPLAN officer and project coordinator.

Fog in Catalonia

The collection of fog water is a technology that is widely used in several countries, but with little implementation in our country due to the lack of really efficient devices adapted to our conditions and the little study of its potential. Some of the best areas in which to install some of the systems developed by LIFE Nieblas and thus begin to capture fog water could be found in the central plateau, Anoia, Bages and Les Garrigues. It is in these areas where the optimum conditions for maximum water uptake are found: fog with air circulation. Other areas such as Montserrat could also be tested, but they are very difficult to access. In addition, specific research projects have also been requested to test them in Lleida and Vic, although the conditions are not so optimal due to the lack of wind on foggy days.

“Other areas of the world with very different climates, such as the Atacama desert or Morocco, have been testing systems with the same objective. Catalonia could also be a place with the potential to obtain water from fog in different areas of the territory”.

VICENÇ CARABASSA, CREAF researcher and Life Nieblas scientific supervisor.

The LIFE Nieblas project is also studying whether the simplest technology, that of individual collectors, works well in all areas of direct influence of the Mediterranean Sea, the coastal mountain range. To this end, it has collaborated with the RESTARC project, the installation of individual collectors in replantings in a quarry undergoing restoration in the Garraf. Specifically, almost 100 collectors have been installed in plantations of Mediterranean species such as wild olive trees and mastic trees.

Uses of fog water

Fog water is even good for drinking. In fact, the tower collectors have been used to collect a type of water christened Nieblagua, which is marketed as drinking water. However, the aim of this project is to collect water for use in the restoration of degraded and very arid areas, through replanting, and for agricultural use in specific areas of the Mediterranean to diversify sources at certain times. In conclusion, these are technologies that should help us to adapt to the forthcoming episodes of drought, which will be increasingly recurrent.