Report expects thermoelectric harvesting to catch on by 2018

For example, Japanese Komatsu trialled 1.5kW thermoelectric modules on its huge construction vehicles, showing that thermoelectric harvesting was no longer just about providing signal power. It had been most widely deployed by the EnOcean Alliance for tiny bursts of UHF signal to operate wireless, batteryless building controls where they were on heating radiators - EnOcean almost entirely uses only electrodynamic and photovoltaic harvesting on its devices. The thermoelectrics was just a back story.

Another pivotal occurrence was Komatsu and others more than doubling efficiency of its thermoelectric devices to up to 7.5%, at least for the smaller ones, for example, creating electricity from electronic components that run hot. Schneider Electric started to use them on wireless sensors triggered and powered by heat outages on such things as copper power busbars.

The day when thermoelectric energy harvesting on hybrid electric engines and exhausts is fast approaching. In IDTechEx visits to AIST in Japan, Komatsu in Japan and the National Physical Laboratory in the UK, plus various EV events in Europe and the USA in 2014, the message was the same: thermoelectric energy harvesting will be in on-road vehicles in 2018. The only disagreement was whether hybrid cars would be first to adopt the technology, or buses.

IDTechEx will enter 2015 with the prediction “Thermoelectric energy harvesting will be on production hybrid electric on-road vehicles from 2018,” adding that the technology will also be commonplace on hybrids in 2020. Logically, thermoelectric energy harvesting is likely to be integrated into large vehicles, such as military or public transport vehicles, first, because the increased efficiency eases the problems of fuel logistics and security of propulsion.

IDTechEx believes that hybrids will outsell pure EVs until 2030. The company expects thermoelectrics to remain the only form of energy harvesting where the material cost is not the largest component of cost, though work is ongoing to make these elements by additive processes instead of current micro-machining. The technology could be very profitable due to limited price sensitivity, and breakthroughs such as less toxic materials and formable materials will be greatly valued. The addressable automotive market is therefore primarily hybrid cars for charging, comprised of around 9m units by 2025 if paybacks are established. 

Conventional cars, which will still be the majority of cars made in 2025, are incorporating more and more energy harvesting to reduce fuel usage. Some alternators work backwards in an equivalent of regenerative braking in EVs. It is therefore possible, but by no means demonstrated, that thermoelectric energy harvesting on hot conventional engines may prove viable.