Thermoelectric energy generators (TEGs) are a small business because of cost and poor performance, but 2019 was a bumper year for TEG research and new approaches, says a new report from IDtechEx.
Thermoelectric Energy Harvesting and Sensing 2020-2030 from IDtechex reports that thermoelectrics is a poor third in energy harvester sales, well behind electrodynamics (wind and water turbines etc.) and photovoltaics on everything.
Nonetheless, new techniques such as quantum and spin thermoelectrics now promise ten times the efficiency.
“The future is electric. 60% of the world’s primary energy is wasted as heat. Turn that heat into electricity and the benefits are huge,” said Raghu Das, IDTechEx CEO and co-author of the report.
“The Internet of Things is nowhere near reaching the predicted billions of nodes yearly monitoring everything from oil spills to forest fires and earthquakes. This is because batteries cannot be changed or charged in such deployments, so you need to make the electricity at the node, typically in the dark. Thermoelectric harvesting from heat differences is often a strong candidate. Another problem is smart watches expiring in hours. They have inadequate area for solar alone so how about electricity from heat, now there is progress in viably exploiting small temperature differences?”
Progress is poor in finding more efficient materials for conventional thermoelectrics at the temperatures where almost all the demand lies – up to 300˚C. However, taking a cue from other forms of energy harvesting, less efficient options with much more acceptable formats and costs are looking good. These include wide area, stretchable, and biocompatible TEGs employing polymers and composites.