Waste heat is energy that has no practical purpose. It is also a wasted energy source.

Ambient air is sucked into a Pressure Amplifier (PA) and sent to a recuperator. The recuperator is positioned in the hot stream of a waste heat source. In the recuperator, energy is transferred to the air which, when heated, builds up pressure. From the recuperator, air is returned to the PA, where it is sent to an expander that drives a shaft coupled to a generator producing electricity.