Achieving energy autonomy in smart farm systems through renewable thermal energy: A scenario-based environmental and economic assessment

The global transition toward renewable energy has been accelerating in response to climate change. South Korea has increasingly expanded the adoption of renewable energy, especially solar power. Smart farms are one example of renewable energy applications but require both electricity and heat demand. Previous studies have shown that the target smart farm does not achieve 100% energy self-sufficiency rate under current conditions. Therefore, renewable energy-based autonomous energy systems and their operational strategy are required to reduce grid dependency with full energy autonomy. This study proposes a scenario-based energy autonomy framework that integrates life-cycle assessment and techno-economic analysis for smart farms with coupled electricity and heat demands using measured operational data. Analysis results indicated that the proposed energy autonomous scenario could reduce CO2 emissions by up to approximately 92% compared to a centralized grid-based system. It also improved economic viability, lowering the LCOE from $0.435 to $0.287/kWh compared with the existing operating model. Sensitivity analysis identified electricity and wood pellet prices as the most influential economic factors. Consequently, a 60% solar-40% biomass configuration provides the optimal balance between environmental performance and economic efficiency. These findings demonstrate the practical feasibility of applying renewable and low-carbon technologies to smart farms within agricultural systems.