Techno-economic analysis of thermoelectrics for waste heat recovery

This article analyses the technical and economic aspects relating to the application of thermoelectric generators in waste heat recovery. It is explained why material cost reductions are unlikely to result in significant reductions in overall device cost. The difficulties associated with manufacturing modules that can withstand high temperatures are shown to result in high cost to power ratios, despite the favorable thermodynamic conditions. This study also compares the performance of thermoelectric generators to Rankine and Stirling cycles and finds that Rankine cycles are able to achieve superior thermal efficiencies at power outputs above 100 kW. Between the ranges of 10 and 100 kW, the thermal efficiency of thermoelectric generators are comparable to that of Rankine cycles. Below 10 kW, thermoelectric generators have greater efficiency than Rankine cycles, but lower efficiency than Stirling cycles. Future expansion of their use in large-scale waste heat recovery will require commercialization of materials with significantly higher thermal efficiency than presently available.