Thermoelectric generator systems for waste heat conversion

© Fraunhofer IPM
Schematic diagram of an internal combustion engine combined heat and power (CHP) system with a thermoelectric heat exchanger or thermoelectric generator. The exhaust gas from the engine is routed through the hot side heat exchanger of the thermoelectric generator. On the cold side of the thermoelectric generator, cooling water is passed through a heat exchanger. The heat flow created by the temperature difference between the hot and cold sides is conducted through the thermoelectric modules and proportionally converted into electrical power.
Kleinfeuerungsanlage mit TEG
© Fraunhofer IPM
Kleinfeuerungsanlagen lassen sich mithilfe von thermoelektrischen Generatoren zu kleinen Kraftwerken (Nano-BHKW) erweitern, in denen neben Wärme auch Strom erzeugt wird.

Thermoelectric generators convert waste heat into electricity – and thus make use of an energy resource that is generally hardly ever used, if at all, in combustion and industrial processes. A thermoelectric generator consists of heat exchangers for hot and cold media and the thermoelectric modules that lie in between them. Despite the relatively low efficiency of thermoelectric modules, thermoelectric generators offer advantages over other power generation technologies. The passive components have no moving parts, are virtually maintenance-free and, thanks to their compactness, can be integrated into existing systems. In the future, for example, small combustion systems can be upgraded into small power plants (nano CHP systems) that generate electricity as well as heat.

Simulation, material, module, system: we are here to support you from the design to the completed system

In the thermoelectrics sector, Fraunhofer IPM can draw on over 20 years of experience in material and module development, measurement technology, simulation methods, and system construction. We build and characterize customer and project-specific system solutions from prototype to application. In recent years, thanks to our intensive research we have been able to significantly advance the development of high-temperature thermoelectric modules . Even high waste heat temperatures of > 600 °C are currently no longer an obstacle to using this technology.

When planning a thermoelectric generator application, we can support you with theoretical calculations regarding the waste heat conversion potential and, if needed, also with the metrological characterization of the heat source. During the development phase, we use suitable simulation tools to specifically match system components such as heat exchangers and thermoelectric modules. The objective in each case is to achieve the highest possible electric power yield in the subsequent application. For system development, in addition to commercially available modules we can rely on our in-house module production line. With this line, we can produce small batches of thermoelectric modules in a wide variety of sizes and designs. Our extensive experience in the modular construction of thermoelectric generators is used in the economic exploitation of different heat sources.

Hot air test stand: Characterization of thermoelectric generator systems

In addition to measuring the thermoelectric properties and long-term stability of thermoelectric modules, we also characterize complete thermoelectric generator systems on our hot air test stand, depending on the application – also as a service for industrial companies. Our special measuring technology makes it possible to realistically test thermoelectric modules as well as prototype systems before their installation in a system.

We support industrial customers in the design and development of thermoelectric systems – from the selection of the thermoelectric material to the construction of finished systems, including power electronics and integration into the respective plant. To make that possible, we draw on many years of technological experience, established supplier contacts and the capacity of our highly specialized workshops and laboratories.



Thermoelectric waste heat recovery


Thermoelectric modules for waste heat recovery