Optimized thermoelectrics for energy harvesting applications

Bismuth telluride thermoelectric (TE) technology is well established in many small scale cooling applications including picnic boxes, auto seats, telecommunications lasers, military smart munitions and satellite applications. Applications using thermoelectric generators (TEGs) operating in reverse, for generating power from small ambient temperature differences are much less mature and not as well understood. Traditional bulk thermoelectric devices and thin film thermoelectric devices are not well suited for these low ΔT, low heat flux applications due to a mismatch between the TEG thermal resistance and the thermal resistance of the small natural convection heat sinks inherent to these energy harvesting applications. This paper will highlight the TE design characteristics for low ΔT energy harvesting TEGs. Performance comparisons between the new bulk TEG devices, traditional thermoelectrics and new thin film thermoelectric approaches will be provided.