Together with partner companies, the team at Isabellenhütte Heusler has developed a new class of thermoelectric materials over the past 15 years to market maturity – the so-called Half-Heusler compounds.
Now thermoelectric waste heat generation based on these materials is about to be ready for the market. The technology is already being tested under realistic everyday conditions in the exhaust lines of passenger cars. With 60 to 70 grams of semi-Heusler material, the thermoelectric generator (TEG) installed in a vehicle achieves an efficiency of up to 5% from the waste heat – not very much at first glance, but this energy would be lost without the TEG anyway. The electrical energy produced in this way is fed into the vehicle electrical system. Thus, more efficient engines with lower fuel consumption can be developed and installed in cars. Isabellenhütte Heusler thus promises a reduction in CO2 emissions per vehicle of up to 4 %.
Against the background of ever stricter environmental regulations by the authorities, the relevance of this technology is obvious. Every gram of CO2 saved is thus of strategic importance. Half-Heusler waste heat generation is also competitive from an economic point of view. With the production processes implemented within the framework of an EU-supported research project, it is possible to achieve the cost target of 0.50 Euros per Watt demanded by the market under large-scale production conditions.
Due to favorable material properties such as high long-term stability and environmental compatibility as well as identical coefficients of expansion of the elements contained, Half-Heusler materials are particularly suitable for high-temperature applications such as the internal combustion engine. Waste heat temperatures of up to 600°C prevail there. With the aim of reducing emissions, recuperation on a semi-Heusler basis is therefore also recommendable for permanently operated high-temperature applications in the energy, metal and chemical industries. And it is also attractive for the end consumer, because it can also be used in stoves or heating systems.
As part of the abovementioned EU research project, Isabellenhütte Heusler has now built a 150 production hall at its headquarters in Dillenburg. Currently, 10 kg of thermoelectric semi-Heusler material per production run are melted there and processed into functional components. This volume is to be increased to 50 kg by the end of the project in December 2019. The system enables a marketable production volume of up to 500 kg per production run. This corresponds to an annual production of 25 tons.