A key review of geothermal heat pumps: Exergoeconomic and environmental aspects with prospects for further development

A comprehensive analysis of geothermal heat pumps (GHPs) was conducted, emphasizing their technoeconomic, exergoeconomic, and environmental aspects apart from previous literature studies. A thorough, extended literature review was performed to identify the latest trends, challenges, and innovations in GHP technology. This study's novelty is in its multifaceted evaluation of GHP systems, integrating exergoeconomic analysis with a broader environmental impact assessment, an area largely underexplored in previous research. Significant improvements in system performance were observed through incorporating additional heat sources like wind turbines, solar thermal panels, and organic Rankine cycle systems. These integrations resulted in notable enhancements in performance efficiency (COP), heating load production, and overall seasonal efficiency, with COP increases of up to 56.92% and heating load improvements of up to 77.8%. Moreover, the environmental impact of hybrid systems was reduced, with substantial decreases in CO2 emissions and other pollutants. A novel modified bibliometric analysis was also developed, revealing gaps in the literature, particularly in the need for advanced exergy analysis and the optimization of hybrid GHP systems for various geographic regions. Interest in GHP research has significantly increased over the past decade. Despite these advances, challenges remain in addressing installation costs, system complexity, and efficiency variations across different climates. This study introduces unique recommendations for optimizing hybrid configurations, reducing installation costs, improving energy storage, and developing adaptive control systems—all of which represent significant contributions to the field.