Scalable Nanostructured Thermoelectric Generation System for Industrial Waste Heat Recovery

Every year, an estimated seven quadrillion British thermal units of energy, about 15 percent of total energy consumed in the United States, is lost in liquid and gasous waste streams from industrial energy systems. The energy from low-to-medium-grade waste heat (50-250 Celcius) cannot be efficiently recovered by conventional heat exchanger technologies, because of its distributed nature and insufficient temperature difference. Thermoelectric generation technologies are not yet economically viable. This project will significantly advance thermoelectric generation technology by developing nanostructured thermoelectric materials. These materials, which will have a thermoelectric figure of merit greater than 2 and will be available in flexible and large sizes, will be integrated into a universal distributed thermoelectric waste heat recovery system with an overall conversion efficiency of about 20 percent. In Phase I, the feasibility of the new nanostructured flexible thermoelectric generation system will be demonstrated by the assembly and test of a subscale proof-of-concept prototype. The prototype will have 5 percent conversion efficiency with a thermoelectric figure-of-merit greater than 1. In Phase II, an optimized prototype with conversion efficiency approaching 20 percent, will be developed. Commercial Applications and other Benefits as described by the awardee: The distributed thermoelectric generation system for recovering waste heat from low-to-medium-grade waste heat streams should save significant energy costs. In addition, the system should be able to provide remote, highly-reliable low-power sources for pipeline and telecommunication infrastructure monitoring. Another major application lies in the auto industry, where fuel-efficient and hybrid automobiles will benefit from the recovery of vehicular coolant/exhaust heat.