Using Heat To Charge Your EV And Hybrid Batteries

Analysts from IDTechEx have predicted that Automotive Thermoelectric Generators (ATEG), known as thermoelectric energy harvesting, will be on production hybrid electric road vehicles starting in 2018.

These analysts said this technology will be commonplace on hybrids in 2020 and almost entirely to charge the battery, or increasingly supercapacitor or supercabattery used for power.

As explained in the new report, Energy Harvesting/ Regeneration for Electric Vehicles Land, Water & Air 2015-2025, there will be little use on wireless devices through the vehicle because the necessary heat differences will not exist where most of these are positioned.

Logically thermoelectric energy harvesting should go on large vehicles first, believes IDTechEx, including military ones because the increased efficiency does not just save money, it eases the problems of fuel logistics (the U.S. Military plans a 70 percent reduction in fuel consumption for this reason) and security of propulsion.

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“Hybrids will outsell pure electric vehicles until 2030,” said Dr. Peter Harrop, Chairman of IDTechEx. “Pure EVs do not have adequate heat differences for thermoelectrics, so the market for thermoelectrics, once established, will be ongoing. We expect 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 the current micro-machining.”

One implication is that the materials can be profitable due to limited price sensitivity and breakthroughs such as less toxic materials and formable materials will be greatly valued, added IDTechEx. The addressable automotive market is therefore primarily hybrid cars for charging – around 9 million units in 2025 if paybacks are established.

More speculatively, conventional cars, which are predicted to still be the majority of cars made in 2025, are incorporating more and more energy harvesting to reduce fuel usage since the starter heating Ventilating Air Conditioning HVA batteries can be loaded at up to 500 watts in them these days. Some stop-start is electromechanical energy harvesting and some alternators work backwards in an equivalent of regenerative braking in EVs. It is possible, but by no means demonstrated, that thermoelectric harvesting on all those hot conventional engines may prove viable adding tens of millions to our figure for addressable market in 2025, stated IDTechEx.