Sunday, 29 September 2019
4:00 p.m. – 5:00 p.m.
Auditorium between bldg 4&5, level 0, room 0215
“Self-cooling greenhouses for food production in very hot climates” by Prof. Philip Andrew Davies, Professor, School of Engineering
Abstract
Combined pressures of population growth, global warming and resource scarcity require innovative approaches to food cultivation in arid areas. Protected cultivation in greenhouses can conserve water and improve crop yields, but in hot climates greenhouses will usually require cooling. First, I will review some earlier collaborative research into cooled greenhouses, which led to the construction of several prototypes. Second, I will focus on greenhouse cooling for very hot climates like that of Saudi Arabia, where cooling will generally require a significant energy input. Use of solar energy for greenhouse cooling seems an attractive proposition, but some studies have shown that the footprint of solar collectors for this purpose may be large – even exceeding the footprint of the greenhouse itself. So it is interesting to explore the feasibility of solar-powered greenhouse cooling. In this context, I will introduce and discuss the idea of a self-cooling greenhouse as one that sacrifices a fraction g of the incident solar energy to drive a refrigeration system, thus lowering internal temperature below ambient temperature. Using thermodynamic principles, I will show that this fraction can be as small as g=6% in the ideal case. Practical implications for the development of self-cooling greenhouses will be discussed.
Bio
Prof. Philip has over 30 years of academic and industrial research experience. The aim of his current research is to achieve sustainable utilization of water and energy resources in arid countries. His research areas include: desalination and water re-use, solar-powered cooling using seawater, Seawater Greenhouse technology, and negative emissions technologies. Philip participates in several international collaborations in regions including North Africa, the Middle East and the Indian sub-continent. In 2018, his work gained the Green Gown ‘Research with Impact’ Award, for studies that led to the development of cooling and desalination technologies to create Seawater Greenhouses that are enabling food to be grown sustainably in arid world regions.