Greenhouse Heating Using Geothermal Brine: A Case Study from Dieng

Abstract

This study examines the feasibility of utilizing geothermal brine from the Dieng Geothermal Field to support greenhouse heating for highland potato cultivation. A thermodynamic simulation was conducted to estimate the heat load, mass flow, and heat exchanger requirements for a 70 m² greenhouse. Results indicate that a brine flow rate of 0.073 kg/s and a secondary fluid flow of 0.056 kg/s are sufficient to maintain internal temperatures of 18–21°C. The system requires only 0.26 m² of heat exchanger surface area, making it compact and scalable. The use of low-grade geothermal heat enhances the overall thermal efficiency of the plant and reduces dependency on fossil fuels. The proposed system offers agronomic benefits, including improved tuber quality and yield (estimated 15–25%) during cold seasons. Environmental advantages include reduced emissions and optimized energy use. Challenges such as silica scaling and initial investment are acknowledged, with recommendations for mitigation. This research highlights a sustainable pathway for integrating geothermal resources into protected agriculture, especially in highland regions.