S06 - Session O1 - Using solar energy and absorption chiller to heat, cool and dehumidify tomato greenhouses in France: a feasibility study

Authors: Ariane Grisey *, Christophe Levaillant, Vincent Stauffer, Christophe Tardy, Philippe Sourice, Florent Saunier

In France, the main issues for high-tech greenhouses are to reduce the use of fossil energy for heating, because this type of energy is responsible for greenhouse gas emissions, and to control by cooling the temperature which increases during spring and summer periods due to climate change. A first feasibility study showed that a solar collector field with a surface area of 30% of the greenhouse area can provide an energy mix that rapidly paid for itself in regions where heating was used throughout the year. However, when using solar energy there is the discrepancy between the very high energy production during the summer period and the heating needs of greenhouses which are highest during the winter period. The use of an absorption chiller to produce cold (around 7°C) for cooling or dehumidifying and warm water (around 35°C) from solar heat for heating could be an opportunity for year-round conditions. The present study aims to evaluate the performance of an absorption chiller unit in a semi closed greenhouse with 3 different climatic conditions in France: northern oceanic, southern oceanic and Mediterranean. Sizing, equipment, system and power have been studied. This solution is compared with cooling unit powered by photovoltaic panels and geothermal water-to-water heat pump. The next step will be to set up a trial on a significant scale to confirm the merits of solar energy to control climate in greenhouses.