A review of heat pipe thermoelectric generators: principles, applications, and challenges

The utilization of thermoelectric generator (TEG) and heat pipe (HP) technologies has gained significant attention as efficient solutions for renewable energy and recovering medium-to-low temperature waste heat, owing to their unique and unmatched advantages. Integrating HP and TEG to form a heat pipe thermoelectric generator (HP-TEG) enables improved heat transfer among heat source, cold source, and thermoelectric modules (TEMs), leading to improved TEG performance. This review systematically categorized and examined the application of HP-TEG across common energy recovery fields — following a brief introduction to its structure and operational principles. Moreover, an overview of the development prospects and application potentials of HP-TEG is provided at multiple levels, including materials, devices, and system configurations. Although HP-TEG is still mainly confined to laboratory research, it is emerging as a promising avenue for future applications owing to encouraging research results. This review supports the advancement and progress of HP-TEG technology.