Using solar energy and an absorption chiller to heat, cool and dehumidify tomato greenhouses in France: a feasibility study

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 the temperature by cooling which increases during spring and summer due to climate change.
A first feasibility study showed that a solar collector field representing 30% of the greenhouse surface area can provide an energy mix that rapidly pays for itself in regions where heating is 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 water (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.
The sizing, equipment, system and power have been studied.
A reduction of up to 50% in fossil energy use can be achieved.
This system is compared with a cooling unit powered by photovoltaic panels and a 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 for climate control in greenhouses.

XXXI International Horticultural Congress (IHC2022): International Symposium on Innovative Technologies and Production Strategies for Sustainable Controlled Environment Horticulture

A. Grisey, C. Levaillant, V. Stauffer, C. Tardy, P. Sourice, F. Saunier

solar collectors, energy savings, semi-closed greenhouse, investment cost

https://doi.org/10.17660/ActaHortic.2023.1377.9