TY - JOUR A1 - Dzekan, D. A1 - Waske, Anja A1 - Nielsch, K. A1 - Fähler, S. T1 - Efficient and affordable thermomagnetic materials for harvesting low grade waste heat N2 - Industrial processes release substantial quantities of waste heat, which can be harvested to generate electricity. At present, the conversion of low grade waste heat to electricity relies solely on thermoelectric materials, but such materials are expensive and have low thermodynamic efficiencies. Although thermomagnetic materials may offer a promising alternative, their performance remains to be evaluated, thereby hindering their real-world application. Here, the efficiency and cost effectiveness of thermomagnetic materials are evaluated for the usage in motors, oscillators, and generators for converting waste heat to electricity. The analysis reveals that up to temperature differences of several 10 K, the best thermomagnetic materials have the potential to compete with thermoelectric materials. Importantly, it is found that the price per watt of some thermomagnetic materials is much lower compared to that of present-day thermoelectrics, which can become competitive with conventional power plants. This materials library enables the selection of the best available thermomagnetic materials for harvesting waste heat and gives guidelines for their future development. KW - Waste heat conversion KW - Magnetic materials KW - Thermomagnetic generator PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-541493 DO - https://doi.org/10.1063/5.0033970 VL - 9 SP - 1 EP - 9 PB - AIP Publishing CY - Melville, USA AN - OPUS4-54149 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Waske, Anja T1 - Fundamentals of Energy harvesting N2 - An introduction to the principles of energy harvesting and conversion, the main technology types and their application is given. A particular focus is on thermomagnetic energy harvesting. T2 - EU ITN Heat4Energy School CY - Dresden DA - 14.10.2024 KW - Energy harvesting KW - Magnetic materials PY - 2024 AN - OPUS4-62285 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Waske, Anja T1 - Energy conversion of waste heat using thermomagnetic materials N2 - To date, there are very few technologies available for the conversion of low-temperature waste heat into electricity. Thermomagnetic generators are one approach proposed more than a century ago. Such devices are based on a cyclic change of magnetization with temperature. This switches a magnetic flux and, according to Faraday’s law, induces a voltage. We demonstrated that guiding the magnetic flux with a pretzel-type topology of the magnetic circuit improves the performance of thermomagnetic generators by orders of magnitude [1]. From an ideal material’s perspective, several similarities with magnetocaloric materials [2] can be found, like a sharp first-order like magnetostructural transition, low hysteresis and high thermal diffusivity. This makes some magnetocaloric materials good candidates also for thermomagnetic energy harvesting, like e.g. (MnFe)2P-based and La(Fe,Si)13-based compounds. Recently, the EU MSCA initial training network Heat4Energy [2] was started with the aim of making three thermomagnetic energy converters for low grade waste heat (<100°C) to electricity with different power output ranges. While the smallest demonstrator operates with thin film materials, the two larger machines use bulk material, for which different processing and shaping routes are explored. In collaboration with the industrial stakeholders of the project, up-scalability and practical application issues of materials processing will be addressed during the project. After an introduction into the technological background and the ITN project, we will present first results on 3D printing and non-destructive imaging of the thermomagnetic parts. T2 - Advances in Magnetics (AIM) 2025 CY - Bressanone, Italy DA - 10.02.2025 KW - Energy harvesting KW - Thermomagnetic energy conversion KW - Magnetic materials PY - 2025 AN - OPUS4-65201 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Waske, Anja T1 - Energy conversion of waste heat using thermomagnetic materials N2 - To date, there are very few technologies available for the conversion of low-temperature waste heat into electricity. Thermomagnetic generators are one approach proposed more than a century ago. Such devices are based on a cyclic change of magnetization with temperature. This switches a magnetic flux and, according to Faraday’s law, induces a voltage. We demonstrated that guiding the magnetic flux with a pretzel-type topology of the magnetic circuit improves the performance of thermomagnetic generators by orders of magnitude [1]. From an ideal material’s perspective, several similarities with magnetocaloric materials [2] can be found, like a sharp first-order like magnetostructural transition, low hysteresis and high thermal diffusivity. This makes some magnetocaloric materials good candidates also for thermomagnetic energy harvesting, like e.g. (MnFe)2P-based and La(Fe,Si)13-based compounds. Recently, the EU MSCA initial training network Heat4Energy [2] was started with the aim of making three thermomagnetic energy converters for low grade waste heat (<100°C) to electricity with different power output ranges. While the smallest demonstrator operates with thin film materials, the two larger machines use bulk material, for which different processing and shaping routes are explored. In collaboration with the industrial stakeholders of the project, up-scalability and practical application issues of materials processing will be addressed during the project. After an introduction into the technological background and the ITN project, we will present first results on 3D printing and non-destructive imaging of the thermomagnetic parts. Furthermore, we will review criticality issues of materials employed in this new technology. T2 - MRS Spring Meeting Seattle CY - Seattle, WA, USA DA - 07.04.2025 KW - Energy harvesting KW - Magnetic materials KW - Thermomagnetic energy conversion PY - 2025 AN - OPUS4-65198 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Waske, Anja T1 - Energy conversion of waste heat using thermomagnetic materials N2 - To date, there are very few technologies available for the conversion of low-temperature waste heat into electricity. Thermomagnetic generators are one approach proposed more than a century ago. Such devices are based on a cyclic change of magnetization with temperature. This switches a magnetic flux and, according to Faraday’s law, induces a voltage. We demonstrated that guiding the magnetic flux with a pretzel-type topology of the magnetic circuit improves the performance of thermomagnetic generators by orders of magnitude [1]. From an ideal material’s perspective, several similarities with magnetocaloric materials [2] can be found, like a sharp first-order like magnetostructural transition, low hysteresis and high thermal diffusivity. This makes some magnetocaloric materials good candidates also for thermomagnetic energy harvesting, like e.g. (MnFe)2P-based and La(Fe,Si)13-based compounds. Recently, the EU MSCA initial training network Heat4Energy [2] was started with the aim of making three thermomagnetic energy converters for low grade waste heat (<100°C) to electricity with different power output ranges. While the smallest demonstrator operates with thin film materials, the two larger machines use bulk material, for which different processing and shaping routes are explored. In collaboration with the industrial stakeholders of the project, up-scalability and practical application issues of materials processing will be addressed during the project. After an introduction into the technological background and the ITN project, we will present first results on 3D printing and non-destructive imaging of the thermomagnetic parts. Furthermore, we will review criticality issues of materials employed in this new technology. T2 - MRS Fall Meeting Boston CY - Boston, MA, USA DA - 01.12.2025 KW - Energy harvesting KW - Thermomagnetic energy conversion KW - Magnetic materials PY - 2025 AN - OPUS4-65197 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -