Home owners of the future may be able to save on electricity costs by simply buying a can of paint thanks to a new study by researchers from the Ulsan National Institute of Science and Technology (UNIST) and the Korea Electrotechnology Research Institute (KERI).
Paints that can produce electricity have been an area of study for a while now. One type, photovoltaic paint, can take the sun's light and turn it into electricity, essentially giving people the ability to create "painted-on solar panels." This new paint, on the other hand, is thermoelectric and produces electricity by harnessing the waste heat from hot surfaces. It combines bismuth telluride (Bi2Te3) with molecular sintering aids and can be applied with a brush to flat or curved surfaces, making it applicable to almost anything.
The results of the team's study showed that their paint could produce an output of 4 mW/cm2 with an energy conversion efficiency of zT values up to 0.67 for n-type and 1.21 for p-type particles. The paper compares it with other thermoelectric paints, saying it bested conventional bismuth telluride paints (ZT≈0.8–1.0) and is close to the performance of newer nanostructured thermoelectric materials (ZT≈1.1–1.9).
In the future, this paint could be used to recover wasted heat energy from everything from refrigerators to engines. Jae Sung Son, a co-author of the study, told Phys.org, "I expect that the thermoelectric painting technique can be applied to waste heat recovery from large-scale heat source surfaces, such as buildings, cars, and ship vessels."
He added that it could also be applied to homes: "[The] temperature of a building's roof and walls increases to more than 50°C [122°F] in the summer. If we apply thermoelectric paint on the walls, we can convert huge amounts of waste heat into electrical energy."
Combine this with other innovations like solar windows and solar roof shingles, and people in the future will have many options if they want to live off-grid, away from power plants running on fossil fuels. Thanks to this special paint, you may not only be able to save on your electric bill, you may also help save the environment.