Designing Technology Diffusion Roadmaps of Thermoelectric Generators Toward a Carbon-Neutral Society

Thermoelectric generators (TEGs) have the potential to contribute significantly to the realization of a carbon-neutral society by recovering electrical energy from various types of waste heat. Potential applications include wireless sensors, automobiles, and wearable devices. Despite their promise, however, TEGs have not been widely diffused due to their currently high cost and low energy conversion efficiency. This article aims to design technology diffusion roadmaps in order to clarify the gap between market needs and technological development, and discusses ways to bridge this gap. Drawing on the backcasting-based roadmap design method developed previously by the authors, TEG roadmaps were prototyped using online interviews with two companies that are developing and marketing their own TEGs for specific applications. Based on the responses, a roadmap design process consisting of five steps—problem setting, preparation, information gathering, structuring and analyzing the results, and feedback—was developed. To demonstrate the proposed method, a case study in which various digital platforms and tools were utilized to efficiently exploit the knowledge and opinions of participating experts was conducted online. Results revealed a pathway by which TEGs could be effectively diffused to meet both social and market needs over the next 30 years. Internet of Things sensors and automobiles were identified as promising applications for the near term, while, for the longer term, the need to develop new solutions and surrounding technologies in order to expand future demand for TEGs was made evident.