Advancing waste heat potential assessment for net-zero emissions: A review of demand-based thermal energy systems

Abstract

Amid the global energy and climate crises, research on waste heat recovery has become imperative, with extensive studies focusing on assessing waste heat potential and evaluating recovery technology performance. However, few studies have addressed the crucial relationship between waste heat potential and recovery technology concerning energy demands, essential for efficiently harnessing energy from waste heat sources. In this study, a comprehensive review of the latest research on waste heat potential and recovery technologies is conducted, and an overall roadmap for waste heat utilization is newly presented based on the key findings. The types and temperature ranges of waste heat sources and sinks are redefined based on recent research outputs. In addition, various methods for estimating the waste heat potential and specific considerations for each step are discussed in detail. Waste heat recovery technology is classified into four sections according to the final energy produced: power generation, heating, cooling, and desalination. The working principles and characteristics of each system are described and compared, with each conclusion followed by a thorough investigation regarding efficiency, operating temperature, capacity, capital cost, and technology readiness level. The proposed framework is expected to address knowledge gaps and provide guidelines for constructing a more accurate and useful waste heat potential map that aligns with the energy demands of a region of interest.