Hybrid energy system for reverse osmosis desalination: Kalina cycle power from an abandoned oil well with hydrogen and battery backup during geothermal well maintenance

Abstract

This study evaluates the integration of geothermal abandoned oil wells for power generation and desalination, addressing the dual challenges of energy and water scarcity. Using advanced simulation tools—Engineering Equation Solver for the Kalina cycle system 11, Wave for the reverse osmosis system, and HOMER for hybrid energy optimization—the research integrates geothermal power, battery storage, and hydrogen storage. The geothermal Kalina cycle system 11 generates efficient power using a water-ammonia mixture, producing 210 kWh at 15 bars and 215 kWh at 20 bars. Exergy analysis showed that higher pressures enhanced system efficiency, compactness, and resilience. The two-stage reverse osmosis system, with a recovery rate of 55 %, produced 805.1 m³/day of potable water at a specific energy consumption of 4.78 kW/m³, confirming its energy-efficient operation. An optimized strategy, developed using HOMER, limited geothermal Kalina cycle system 11 shutdowns from one month a year to a week every three months. During these outages, a hybrid energy solution involving 1146 kg of hydrogen storage and 10,500 12-V batteries ensured reliable operation of the reverse osmosis system, minimizing costs. The hybrid system demonstrated the complementary roles of hydrogen and batteries. While hydrogen storage provided 14,920 kWh/year, the battery system efficiently supplied the reverse osmosis's energy needs for up to seven days. This study validates the technical and economic feasibility of integrating the geothermal Kalina cycle system 11 with hybrid energy storage and desalination technologies, highlighting the importance of simulation tools in optimizing integrated energy-water systems.