Journal of sustainable Energy Systems

Journal of sustainable Energy Systems

Thermoeconomic and Exergy Evaluation of Shallow and Deep Geothermal Systems for Greenhouse Heating in Cold Climates (Case Study: Meshginshahr)

Document Type : Original Article

Authors
1 Agricultural Engineering Research Department, West Azerbaijan Agricultural and Natural Resources Research and Education Center, AREEO, Urmia, Iran
2 Department of Mechanical Engineering, Payame Noor University, Tehran, Iran
10.22059/ses.2026.413773.1236
Abstract
This study presents an energy and exergy analysis of two geothermal systems, including shallow Ground Source Heat Pump (SGHP) and Deep Geothermal Energy (DGE) system, for supplying the heat demand of a greenhouse located in the cold region of Meshginshahr, Iran. The thermodynamic modeling was carried out using Engineering Equation Solver (EES) based on real data from the Sabalan geothermal field. Under design conditions (outdoor temperature of −10 °C and indoor temperature of 20 °C, the greenhouse heating load was calculated to be 126 kW. The results indicate that the SGHP system, utilizing soil at an average temperature of approximately 10 °C, achieves a coefficient of performance (COP) of about 3.5 and an exergy efficiency of 0.62. In contrast, the DGE system, with a geothermal fluid inlet temperature of 85 °C, demonstrates superior thermodynamic performance, reaching an equivalent COP of around 20 and an exergy efficiency of 0.68. This performance improvement is primarily attributed to the higher source temperature and the significantly lower electrical energy requirement in the deep geothermal system. From an economic perspective, although the shallow geothermal system benefits from simpler implementation and lower infrastructure requirements, leading to a shorter payback period, the deep geothermal system offers more stable long-term performance due to its minimal electricity consumption and reduced operational costs. Furthermore, the findings highlight that source temperature and thermal properties of the surrounding environment play a critical role in determining the overall system performance.
Keywords
Subjects

[1].   Abedrabboh, O., M. Koç, and Y. Biçer, Modelling and analysis of a renewable energy-driven climate-controlled sustainable greenhouse for hot and arid climates. Energy Conversion and Management, 2022. 273: p. 116412.
[2].   Cimmino, L. and M. Vicidomini, Renewable Energy Systems 2023. Applied Sciences, 2024. 14: p. 1918.
[3].   Calise, F., et al., Dynamic Modelling and Energy, Economic, and Environmental Analysis of a Greenhouse Supplied by Renewable Sources. Applied Sciences, 2023. 13: p. 6584.
[4].   Hessari, F.A., Sectoral energy consumption in Iran. Renewable and Sustainable Energy Reviews, 2005. 9(2): p. 203-214.
[5].   Jahandideh, M., et al., Leveraging renewable energy for mitigating greenhouse gas emissions in Iran. Energy Conversion and Management: X, 2026. 30: p. 101632.
[6].   Mollahosseini, A., et al., Renewable energy management and market in Iran: A holistic review on current state and future demands. Renewable and Sustainable Energy Reviews, 2017. 80: p. 774-788.
[7].   Gülergül, Ö. and A. Baba, Leveraging Geothermal Energy for Sustainable Agricultural Growth: A Pathway to Regional Economic Revitalization through Heated Greenhouse Systems. 2025.
[8].   Wahid, M.N., et al., A strategic analysis of geothermal energy for sustainable energy transition: Case study from Indonesia. Energy Conversion and Management: X, 2025. 28: p. 101303.
[9].   Ogail, A., et al., A Review of Exploiting Shallow Geothermal Energy through Tunnels: Current Status and Future Prospects. Renewable Energy, 2024. 238: p. 121958.
[10].         Li, G., et al., Status and challenges of deep geothermal exploitation and energy storage technology: a comprehensive review. GeoEnergy Communications, 2025. 1(1): p. 5.
[11].         Boyacı, S., et al., Energy Efficiency in Greenhouses and Comparison of Energy Sources Used for Heating. Energies, 2025. 18(3): p. 724.
[12].         Kassem, M.A. and A. Moscariello, Geothermal energy: A sustainable and cost-effective alternative for clean energy production and climate change mitigation. Sustainable Futures, 2025. 10: p. 101247.
[13].         Lund, J.W., Geothermal ResourcesgeothermalresourceWorldwide, Direct Heat Utilizationgeothermalresourcedirect heat utilizationof, in Encyclopedia of Sustainability Science and Technology, R.A. Meyers, Editor. 2012, Springer New York: New York, NY. p. 4353-4379.
[14].         Iorio, M., et al., Low Enthalpy Geothermal Systems in Structural Controlled Areas: A Sustainability Analysis of Geothermal Resource for Heating Plant (The Mondragone Case in Southern Appennines, Italy). Energies, 2020. 13(5): p. 1237.
[15].         Noorollahi, Y. and R. Itoi, Production capacity estimation by reservoir numerical simulation of northwest (NW) Sabalan geothermal field, Iran. Energy, 2011. 36(7): p. 4552-4569.
[16].         Noorollahi, Y., et al., Review of two decade geothermal energy development in Iran, benefits, challenges, and future policy. Geothermics, 2019. 77: p. 257-266.
[17].         Chahartaghi, M., et al., Energy and exergy analyses and thermo-economic optimization of geothermal heat pump for domestic water heating. International Journal of Low-Carbon Technologies, 2019. 14(2): p. 108-121.
[18].         Seyedrahimi-Niaraq, M., et al., Development of an updated geothermal reservoir conceptual model for NW Sabalan geothermal field, Iran. Geothermal Energy, 2017. 5(1): p. 14.
[19].         Ghaedrahmati, R., et al., 3-D inversion of MT data from the Sabalan geothermal field, Ardabil, Iran. Journal of Applied Geophysics, 2013. 93: p. 12-24.
[20].         Mehregan, M., et al., Energy and exergy analyses and thermo-economic optimization of geothermal heat pump for domestic water heating. International Journal of Low-Carbon Technologies, 2019.
[21].         Kakaç, S. and H. Liu, Heat Exchangers: Selection, Rating, and Thermal Design, Second Edition. 2002. 1-493.
[22].         Mustafa Omer, A., Ground-source heat pumps systems and applications. Renewable and Sustainable Energy Reviews, 2008. 12(2): p. 344-371.
[23].         Kusuda, T. and Achenbach, P. (1965), Earth temperature and thermal diffusivity at selected stations in the United States:, , National Institute of Standards and Technology, Gaithersburg, MD, [online], https://doi.org/10.6028/NBS.RPT.8972 (Accessed June 21, 2026)
[24].         Dalla Santa, G., et al., An updated ground thermal properties database for GSHP applications. Geothermics, 2020. 85: p. 101758.
[25].         Options and Applications for Ground Source Heat Pumps, in An Introduction to Thermogeology: Ground Source Heating and Cooling. 2012. p. 150-201.
[26].         Peng, Z., S. Carrigan, and O. Kornadt, Investigation of the influence of different room geometries and wall thermal transmittances on the heat transfer in rooms with floor heating. Energy and Buildings, 2024. 317: p. 114391.
[27].         Roumi, S., et al., Direct Applications of Geothermal Energy; Economic and Environmental Assessment: Meshkin-Shahr, Iran. 2017.
[28].         Yousefi, H., et al., Cascading uses of geothermal energy for a sustainable energy supply for Meshkinshahr City, Northwest, Iran. Geothermics, 2019. 79: p. 152-163.
[29].         Rezaei, A., M. Rezaeian, and S. Porkhial, The hydrogeochemistry and geothermometry of the thermal waters in the Mouil Graben, Sabalan volcano, NW Iran. Geothermics, 2019. 78: p. 9-27.
[30].         Al-Hamed, K.H.M. and I. Dincer, Investigation of a concentrated solar-geothermal integrated system with a combined ejector-absorption refrigeration cycle for a small community. International Journal of Refrigeration, 2019. 106: p. 407-426.
[31].         Tempesti, D., G. Manfrida, and D. Fiaschi, Thermodynamic analysis of two micro CHP systems operating with geothermal and solar energy. Applied Energy, 2012. 97: p. 609-617.
[32].         Guisado, J.M., A. Carro, and R. Chacartegui, Avoidable exergy performance analysis in the integration of an electrothermal energy system based on transcritical CO2 cycles. Energy Conversion and Management, 2026. 348: p. 120706.