There's a new paint that helps capture thermal energy from waste heat for conversion into energy. Scientists from Ulsan National Institute of Science and Technology (UNIST), Korea Institute of Science and Technology (KIST) have jointly developed thermoelectric paint that can generate electrical energy from waste heat. The idea of utilizing energy from waste heat has been heavily discussed lately. And that's also the main reason why scientists are focusing on waste heat as a potential energy source. It's estimated that two-thirds of all produced energy is lost in the form of waste heat. The new thermoelectric paint is particularly interesting in this regard because it can be applied to almost any surface from which we want to capture and process waste heat. Most existing thermoelectric devices are flat and rigid, so when you apply them to objects like refrigerators or engines, there's always still a lot of waste heat that escapes without being captured. This doesn't happen with paints, making it possible to maximize the amount of heat removed that is subsequently converted. The coating contains bismuth telluride, which is often used in thermoelectric materials, and a special process fixes its particles together. The coating is simply applied to the surface and then heated to high temperatures for 10 minutes, which increases its density and enables more efficient conversion of thermal energy to electrical energy. 
Tests showed that devices painted with thermoelectric paint exhibit high output power density of 26.3 mW/cm2. This value is comparable to conventional thermoelectric material and is significantly better than all other thermoelectric elements based on paints and pastes. According to scientists, the paint would be particularly useful for capturing heat from building walls and roofs during summer months. The coating can also be used for automobiles and ships, where the energy created this way would be utilized for onboard electronics. At Greenhousing, we would coat all our server racks with the paint. For now, we at least use waste heat to heat all offices and the training room in the data center. More about the project at nature.com ed