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The use of thermo-electric (TE) generation systems in internal combustion engines (ICEs) to reduce the carbon dioxide emission by harnessing the exhaust thermal energy is showing increasing promise. In addition, integration with after treatment devices is a development route for this technology that offers a great potential. Recent work on TE systems have shown that the overall efficiency of present TE generation systems are constrained by, the limitations of the conversion efficiency and operating temperatures of TE materials; fabrication quality, durability and thermal performance of the thermo-electric modules (TEMs); geometrical configuration and heat exchange efficiency of thermo-electric generator (TEG) and; conversion techniques of the TEG's electrical output to a form suitable for vehicle systems.

Recent work on thermo-electric (TE) systems has highlighted the need for refined heat transfer design as well as the long standing need for improved materials performance. Recent work on heat transfer for TE systems has shown that enhanced heat transfer is needed over and above what would normally be seen in a vehicle exhaust system. In particular a better understanding of flow development and boundary layer behaviour is needed to support new design proposals. In the meantime, recent work in TE materials suggests that with the use of skutterudites significant performance benefits can accrue over existing materials. The current generation of TE materials have non-dimensional thermoelectric figure of merit (ZT) values of around 1. Skutterudites have been demonstrated to have ZT values of about 1.4 and can maintain these values over a wider temperature range than do existing materials through the engineering of the TE device.