Period heat source gives thermoelectric power a boost


© Shutterstock

Scientists in the US have found a way to improve the efficiency of thermoelectric power generators (TPGs) – devices designed to convert heat directly into electricity.

TPGs require a heat source, a thermoelectric material that converts heat to electricity, and a power generator. Such devices could be used to recycle heat from power plants or motor vehicles, and could even find use in solar energy conversion. Current research is focused on improving the conversion efficiency of thermoelectric materials but, to date, all proposed designs are either difficult to scale up or uneconomical to produce commercially. Yan Yan and Jonathan Malen at Carnegie Mellon University in Pittsburgh, Pennsylvania, are aiming to solve these problems and have instead focused on changing the type of heat source used.

Current TPGs are designed to be used with constant sources that operate at a consistent temperature, but when Malen’s team tried a periodic heat source they found their TPG device worked more efficiently. Malen says ‘our work amounts to a temporal concentration of heat that increases the instantaneous temperature difference across the thermoelectric generator, thereby improving their performance’. He hopes that the work will inspire research into existing periodic heat sources, as well as the conversion of constant sources into periodic sources in order to improve efficiency.

Jian He an expert in thermoelectric materials at Clemson University, South Carolina, US, describes Malen’s work as ‘achieving a significant system-level efficiency enhancement that is practically inaccessible by current materials development’, adding that the prospect of ‘alternating thermoelectricity’ will profoundly impact the application of thermal power generation.

References

Y Yan and J A Malen, Energy Environ. Sci., 2013, DOI:10.1039/c3ee24158k


Related Content

Harvesting heat

27 October 2014 Premium contentFeature

news image

Philip Ball looks at the materials that harness waste heat and turn it into useful energy

Thermoelectric cost analysis

1 July 2013 Research

news image

Cost considerations for thermoelectric generator design

Most Read

Isotope effect produces new type of chemical bond

22 October 2014 Research

news image

Evidence emerges for vibrational bond first proposed 30 years ago

DNA 'barcodes' used to track food

30 October 2014 Research

news image

Milk has been successfully tracked as it is turned into cheese and yogurt in an advance that could fight food fraud

Most Commented

Square planar iron complex breaks inorganic dogma

31 October 2014 Research

news image

Unusual spin state could open the door to new and exciting chemistry

Indian U-turn on diabetes drug ban

16 August 2013 News and Analysis

news image

Suspension of cheap and popular medicine reversed but will now come with new safety warnings