## 3 Conclusions  
A viable way to improve agricultural operations' sustainability and energy efficiency is to deploy TES devices as thermal batteries in greenhouses. By preserving ideal growth conditions, TES systems can lower interior temperature fluctuations, decrease the need for heating and cooling, and increase crop yields. By reducing the dependency on fossil fuels, integrating TES with renewable energy sources even further improves its environmental advantages. To fully realize the promise of TES in greenhouse applications, future research should concentrate on refining TES materials, enhancing system designs, and evaluating the long-term environmental and economic effects. In this review work, various dimensions and methods of using TES systems inside greenhouses have been examined, and the achievements of previous related works have been evaluated:  
* The promising results obtained from previous works, which show that TES systems should be considered one of the main components of greenhouses today, can be mentioned as an attainment of the present work.
* Most studies employing a PCM in greenhouses as the latent heat type of TES systems have been conducted experimentally, with fewer statistical or analytical investigations. This issue might be viewed as a research gap that should be addressed in future studies.
* Generally, six types of PCMs were employed in greenhouses as TES. These systems used pure paraffin, calcium chloride hexahydrate (CaCl\({}_{2}\),6H\({}_{2}\)O), GH-20, AC27, RT types (RT12, RT15, and RT18 HC), and shape-stabilized PCMs. It can be concluded that paraffin is the most commonly used PCM.
* A very effective and promising way to increase greenhouse efficiency during cold seasons, especially in areas with harsh winters, is to use a rock bed as a thermal battery, an SHTES, a humidifier/dehumidifier, or even a pre-conditioner.
* Most of the previous works presented by researchers in the field of using rock beds for the thermal management of greenhouses were conducted experimentally, and only one numerical work was employed for the thermal analysis of the bed.
* [PERSON] et al. (2018) first presented the most efficient greenhouse-rock bed coupled system design in 1996, in which the humid air injection/suction mechanism was utilized for charging/discharging modes. Other researchers later used this method. However, no detailed analysis has yet been conducted to optimize its performance.  
Figure 36: (**a**) The conceptual aspects of a closed greenhouse in heating and cooling modes (without considering the heat pump cycle) and (**b**) various layouts of the proposed TES systems in the proposed greenhouse by [PERSON] et al. (2019).  
* The range of rock bed porosity considered in the previous works is 0.33-0.49. It is worth mentioning that researchers mostly used a porosity of 0.35. Also, the rock bed's particle diameter range is 0.25-10 cm. The present study also presents research gaps in this field. Most of the work was carried out experimentally, and indeed, to achieve a correct understanding of the phenomena in the system, more accurate methods such as computational fluid dynamics methods should be used; this could be an excellent suggestion for future works.  
Conceptualization, S.S.M.A., L.A. and S.P.; formal analysis, S.S.M.A.; investigation, S.S.M.A.; resources, S.S.M.A., L.A. and S.P.; data curation, S.S.M.A.; writing--original draft preparation, S.S.M.A.; writing--review and editing, S.S.M.A., L.A. and S.P.; supervision, L.A. and S.P.; project administration, L.A. and S.P.; funding acquisition, L.A. and S.P. All authors have read and agreed to the published version of the manuscript.  
NSERC Alliance (ALLRP 565628-21) and Innovee (PSO-2104) in collaboration with Hydro-Quebec, Ferme des Quatre Temps, Serres Royales, Abri Vegetal, Aerogeothermik Inc., Copeland Canada Inc., Atis Energie, and CETAB+.  
Not applicable.  
The authors declare no conflicts of interest.