Advanced passive technology for water saving, sustainable food supply, and comfortable urban space
Authors: Grosso Mario 
Published: November 2013

The advanced technologies presented in this paper are based on a low-environmental-impact, energy-saving,and health-fostering approach, able to fit to the extreme climate and environmental conditions of Qatar. They are addressing 3 of the 12 Cross-cutting Grand Challenges within the Energy and Environment thematic pillar. 3. Sustainable food supply: c (Explore the feasibility of hydroponic, aeroponic and new greenhouse technologies). The advanced technology proposed is applied to a greenhouse which is able to grow hydroponically fresh vegetables in the desert under extremely controlled conditions taking care of water, air, waste management and energy production. Based on previous aerospace experience, the greenhouse proposed is something that surpasses the current state of the art: the energy production for all the hydroponic greenhouse facility is ensured by the use of flexible and transparent solar panels which allows for solar light to illuminate the hydroponic cultures; simultaneously electricity is produced by an integrated PV system made of high-tech conductive polymers embedded inside the plastics of the external walls of the greenhouse. 1. Water reuse: f (Develop and adopt safe and efficient methods of wastewater reclamation and reuse). The water for the alimentation of the hydroponic cultures will be used in closed circuit avoiding losses through a constant monitoring of its key parameters. A series of ion-selective electrodes connected with microelectronic hardware, follows through metering pumps the concentration of nutrients in the water to integrate those depleted during the circulation. Water circulation in the hydroponic culture implies also its enrichment by metabolites such as oxalic acid coming from plants, and the water can accumulate and grow undesired micro-organisms which can build up undesired and noxious biofilm or which could be dangerous for the plants. To eliminate these risks, a patented in-house technology permits to destroy selectively the undesired metabolites released by the plants using the photo-ozonolysis treatment, which not only destroys metabolites like oxalic acid converting them into CO2 and water, but destroys completely all noxious micro-organisms which may grow in the hydroponic water, preventing the undesired bio-film to build-up. 5. Sustainable Urbanisation - Doha as a smart city: d (Develop state-of.the-art technologies in infrastructure systems and materials unique to Qatar but adaptable to global industry) and i (Design and build environments that foster healthy behaviours). A technological transfer from the above-described systems to the thermal mitigation of urban confined spaces is envisioned in this third part of the presented proposal. The greenhouse selective solar ETFE envelop can be applied to outdoor confined spaces in order to realise thermal comfort conditions inside through solar radiation control. The close circuit water pump system is used to sprinkle water from the ceiling of the envelop inducing passive down-draft evaporative cooling. The aeroponic technique allow for vertical vegetation growing on the facades of buildings which become the inner walls of the outdoor confined spaces, thus increasing the cooling effect by transpiration and low-emissivity irradiation. In addition, ground cooling is applied to inlet naturally cooled air from floor vents connected to serpentines of buried pipes under the urban space pavement.