Efficiency assessment of a solar heating cooling system applied to the greenhouse microclimate Abderrahim Bazgaou a,⇑ , Hicham Fatnassi b , Rachid Bouharroud c , Kabira Ezzaeri a , Lahoucine Gourdo a , Ahmed Wifaya c , Hassan Demrati a , Hayat El Baamrani a , Aicha Idoum a , Ahmed Bekkaoui d , Ahmed Aharoune a , Lahcen Bouirden a a Thermodynamics and Energetics Laboratory, Faculty of Science, Ibn Zohr University, BP8106, 80006 Agadir, Morocco b Université Côte d’Azur, INRA, CNRS, ISA, France c National Institute of Agronomic Research INRA Agadir, Morocco d Agronomic and Veterinary Institute Hassan II, Rabat, Morocco article info Article history: Received 11 October 2019 Accepted 18 October 2019 Available online xxxx Keywords: Solar heating cooling system Quartzitic sandstone Surplus air thermal energy storage Agricultural yield Greenhouse microclimate abstract The solar thermal storage is an important issue for greenhouse applications in winter period. For the rea- son that greenhouse operations, such as heating and cooling, consume a large amount of energy. The thermal storage is important to minimize the cost of greenhouse production. Surplus air thermal energy (SATE) is available in greenhouses during all the year, even in the cold period, hence its use in greenhouse applications is possible. In this present work, a solar heating cooling system (SHCS) with quartzitic sand- stone as thermal storage material to store and use the SATE in greenhouse production was operated for cooling and heating processes and its performance was evaluated during winter period. This system con- sists of a quartzitic sandstone and including thermal storage blocks and pipes with fans to manage those processes in greenhouse. This system was located in the Souss-Massa region, Morocco. The heating and cooling of inside air by SHCS can improve the greenhouse microclimate and tomato yield. The results show that the air temperature in greenhouse equipped with SHCS exceeds than that of the control one about 3 °C at night and 6 °C lower during day, with fewer fluctuations. Moreover, the relative humidity was 10% lower at night. The SATE stored was varied between 15.68 and 140 MJ/day in plastic greenhouse with an area of 165 m 2 during day, and 65% of this heat recovered at night. The SHCS was improved the tomato yield about 1.74 kg/m 2 than that of normal production. An economic analysis revealed that this system is very profitable and could generate profits for farmers. Ó 2019 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the International Confer- ence on Plasma and Energy Materials ICPEM2019. 1. Introduction The agricultural greenhouse behaves like a complex physical and biological system, that carries out heat exchanges with the outside and used for the protection of the plant when it is impos- sible to grow outside due to climate and diseases. The greenhouse is a system that improves crop yields by creating comfortable growing conditions. The responsible parameters for the crop growth are light, temperature, relative humidity and nutrients. These factors must be controlled and maintained at optimal levels, which consumes a large amount of energy [1,2]. The conventional systems use the fossil fuels for heating greenhouses [3], which increase the cost of greenhouse production [4]. Consequently, the investment price increases also. For that, many studies have been realized to minimize energy consumption or replace conventional energy sources with renewable and new sources [5–11]. The new systems are based on solar energy as a heat source, this energy will be stored during the day for use it at night in heating applications. Moreover, the solar energy can be stored in thermal storage materials according to three modes: sensible, latent and chemical energy storage [12]. In studies of Singh et al. [13] showed the technological and eco- nomical aspects make sensible heat storage better than latent heat https://doi.org/10.1016/j.matpr.2019.10.101 2214-7853/Ó 2019 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the International Conference on Plasma and Energy Materials ICPEM2019. ⇑ Corresponding author. E-mail address: abde.bazgaou@gmail.com (A. Bazgaou). Materials Today: Proceedings xxx (xxxx) xxx Contents lists available at ScienceDirect Materials Today: Proceedings journal homepage: www.elsevier.com/locate/matpr Please cite this article as: A. Bazgaou, H. Fatnassi, R. Bouharroud et al., Efficiency assessment of a solar heating cooling system applied to the greenhouse microclimate, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2019.10.101