Thirteen quadrillion (3600 terawatt-hours) BTUs of energy is lost annually through waste heat by U.S. industry.
The team cold-sprayed a bismuth-telluride powder on substrates ranging from stainless steel to aluminum silicate and quartz. The sprayed material had a randomly oriented microstructure largely free from pores and the cold-spray deposition was achieved without substantial compositional changes.
A ZT of 0.3 can probably only recover 2-4% of the heat as electricity, but it will be from places where we could recover nothing before
A new application of cold-spray deposition has been demonstrated that can fabricate bulk pieces of thermoelectric Bi2Te3 on a wide variety of substrates, without loss of structural integrity. By entraining particles in a supersonic gas flow, millimeter-thick blocks can be built up on flat or curved surfaces in a matter of seconds, providing a pathway to waste heat recovery from narrow pipes or other, more complicated, shapes.