Converting lower temperature heat into energy
DOI: 10.1063/10.0005429
Converting lower temperature heat into energy lead image
Many things in the world generate at least a little heat, like your laptop or your body. Most of this low-grade heat – generally with temperatures below 100 degrees Celsius – dissipates into the environment. But what if all that heat could be used to power technologies?
Zhang and Wang reviewed thermally regenerative electrochemical cycle (TREC) systems, which have recently gained traction in the scientific community to efficiently turn low-grade heat into electrical energy. The report compares TREC systems to other low-grade heat conversion technologies and discusses what else needs to be done to position the technology for practical applications.
Co-author Qing Wang said TREC systems can be a viable and sustainable way of harnessing energy from the environment if properly integrated with other energy systems.
“More than 50% of the energy produced worldwide is rejected to the environment, mostly in the form of waste heat. And low-grade heat constitutes more than 60% of the total waste heat,” Wang said. “Although this part of the heat is abundant, it is difficult to be utilized due to the distributed nature of heat sources and the low-temperature differential. TREC provides a promising means of addressing the above issues for efficient low-grade heat to electricity conversion.”
By writing this review, Wang hopes readers are encouraged to improve technologies for making TREC heat-to-electricity conversion more efficient.
“It is important to develop new redox couples with higher temperature coefficients to further improve the thermal-to-electrical conversion efficiency,” Wang said. “In addition, new operating mechanisms, such as redox targeting reactions between soluble redox mediator and solid redox active material, could be employed to achieve the most efficient thermoelectric conversion.”
Source: “Thermally regenerative electrochemical cycle for low-grade heat harnessing,” by Hang Zhang and Qing Wang, Chemical Physics Reviews(2021). The article can be accessed at https://doi.org/10.1063/5.0044616 .
