About 90 percent of the world’s power is generated by heat engines that convert heat to mechanical motion, which can then be converted to electricity when necessary. Such heat engines typically operate at 30-40 percent efficiency, losing heat to the environment. Therefore, capturing even a fraction of the low-grade lost heat and converting it to electricity in a cost-effective manner would have a tremendous environmental impact, including massive savings of fuel and reductions in carbon dioxide emissions.
Thermoelectric energy converters can directly convert low-grade heat to electricity using semiconducting materials using the Peltier effect. However, the widespread use of such devices is limited due to the efficiency and cost of component materials. During the last 50 years, researchers have been working to improve the efficiency of thermoelectric materials, but progress has been very slow. Only recently, through nanotechnology, has significant progress been made in increasing the performance of these materials; Professors Arun Majumdar and Rachael Segalman at UC Berkeley have shown that thermoelectric energy conversion is possible using simple molecules sandwiched between metals. This method is a departure from traditional inorganic materials, and one that opens the possibility of thermoelectric materials made of readily available metals and organic molecules that can be synthesized by using low-cost solution processing that can be scaled up.
Next Steps: As part of this project, a group will develop a comprehensive program on new classes of cost-effective and high efficiency thermoelectric materials and devices for waste heat recovery. We propose to conduct cutting edge research for high performance and low-cost thermoelectric energy convertors. Future research may also include exploration of use of advanced thermoelectric materials in small distributed power systems and larger scale centralized power generation.