Available Systems for the Conversion of Waste Heat to Electricity

The conversion of heat into electricity, generally speaking heat-to-power generation, is a wide area of technologies and applications. This paper focuses on available systems, excepted the internal combustion cycles, applied to transform (waste) heat to power. Data of referenced market proved or time-to-market technologies are presented. A database of more than 1100 references has been built. The following categories can be found: Rankine Cycle plant, Organic Rankine Cycle plant, Steam engine, Kalina Cycle plant, Brayton cycle plant, micro gas turbine, closed cycle gas turbine plant, combined cycle gas turbine plant, Stirling engine, Ericsson engine and thermoelectric generator. We intentionally target a range of power from Watts to hundreds of MW, covering the range of temperature [80–1000°C] usually addressed by these systems. The comparison of performances is hereby discussed and compared to thermodynamic principles and theoretical results in the graph Maximum temperature [°C] versus Thermodynamic efficiency. Comparison with Carnot and Chambadal-Novikov-Curzon-Ahlborn efficiencies are performed. A more original contribution is the presentation of the graph Power [W] versus Thermodynamic efficiency. The analysis reveals a monotonous trend inside each technology. Furthermore this general behavior covers a very wide range of power, including technological transitions. Finally, the position of each technology in the map Maximum temperature [°C] versus Power [W] is also analyzed. Explanations based on thermodynamics and techno-economic approaches are proposed.