A comprehensive technoeconomic and environmental evaluation of a hybrid renewable energy system for a smart farm in South Korea

The farming sector like any other industry needs to be decarbonized. Hence, it is essential to meet the energy demands of the farms by adopting energy systems with a low-carbon footprint. Depending on the weather conditions, heating or cooling is needed. Within this context, this study presents a new hybrid renewable decentralized energy system that is designed to satisfy the requirements for heating, cooling, and electricity of a smart farm in South Korea. The under-investigation energy system comprises solar PV arrays, heat pumps, thermal energy storage tanks, and a wood pellet boiler. This study is the first to conduct an inclusive techno-enviroeconomic assessment of such a hybrid energy system by utilizing actual meteorological data on an hourly basis. This enables the model to be dynamic and facilitate accurate and reliable assessments. The modelling efforts have been performed in Aspen Plus and MATLAB to investigate the thermodynamic behaviour of the system. The investigation shows that the proposed system has achieved a daily average temperature of around 23.9°C inside the farm throughout the year with a standard deviation of 2.16°C. For the economic assessment, the levelized cost of energy has been selected as the main economic indicator, and this has been estimated at $0.218/kWh. It is found that the PV panels and the biomass boiler dominate the capital expenditures, and the biomass feedstock is the major contributor to the operating expenditures. Further, the proposed energy system reduces CO2 emissions, by up to 88.94%, when compared to conventional fossil-based energy systems. The outcomes of this study represent a holistic evaluation for such a low-carbon hybrid energy system when applied to greenhouses in Korea and in similar locations.