Capturing Waste Heat

Many processes generate heat as a by-product. Most often the heat by-product is dissapated and thus wasted. Example processes that generate waste heat include: incineration, electricity generation, water heating, manufacturing, central heating, and turning an engine.

If waste heat could be captured and stored, it could potentially power other processes at very low cost. Hi-Z has developed a number of thermoelectric modules (TM) that convert low-grade waste heat into electricity.

The TM resumbles a hot pan holder. Composed of bismuth telluride-based alloys, Hi-Z's TM requires a heat flux of approximately 8 watts per cm2 to generate electricity. At 200°C, the Hi-Z TM converts 5% of the thermal energy that passes through it into electricity, generating 14 watts. It will work without maintenance for tens of thousands of hours when properly installed. It is most effective when tightly compressed and electrically insulated between a heat source and a heat sink. A spring-loaded pressure plate that allows for thermal expansion is ideal.

The result is a TM layer in close surface contact with a heat emitter. The TM will then produce electricity whenever there is heat.