Periodic Reporting for period 1 - INFERNO (RECYCLING INDUSTRIAL WASTE HEAT THROUGH THE APPLICATION OF THERMOPHOTOVOLTAIC AND THERMOELECTRIC: A NOVEL HYBRID TECHNOLOGY FOR ELECTRICITY GENERATION)
Reporting period: 2024-05-01 to 2025-10-31
Energy-intensive, high-temperature processing industries lose more than 50% of their energy as waste heat during production, accounting for 200 TWh of power each year in Europe. While many technologies exist to convert waste heat into electricity, their adoption at an industrial scale remains limited. Specific barriers—such as the efficiency and cost of these renewable technologies, along with the challenges of integrating them into existing production lines—have restricted their widespread use as industrial heat recovery solutions. Innovative approaches that improve efficiency through new modular technologies are therefore urgently required, allowing retrofitting into production lines to save energy and reduce greenhouse gas emissions.
The primary goal of INFERNO is to develop a new hybrid platform system integrating thermophotovoltaics (TPV), metasurface collectors (MetaS), and thermoelectric generators (TEG), aiming to achieve a breakthrough in sustainable energy harvesting from industrial waste heat. The project will develop new infrared-sensitive, low-bandgap (<0.7 eV) TPV cells with integrated plasmonic metamaterials to enhance photon absorption and improve overall heat-to-electricity conversion efficiency to 25%, alongside high-performance TEG devices made from earth-abundant materials with an efficiency of 10%. Using an innovative design strategy, these components will be combined into a modular, hybrid energy harvesting system that can be easily integrated into production lines.
To achieve this goal, INFERNO brings together expertise in materials research, modeling, cell fabrication, thermoelectricity, and electronics on a pan-European scale. The integrated hybrid system and its components (TPV, MetaS, TEG) will be tested in three pilot demonstrations across three countries to convert waste heat into electricity and reduce greenhouse gas emissions.
The primary goal of INFERNO is to develop a new hybrid platform system integrating thermophotovoltaics (TPV), metasurface collectors (MetaS), and thermoelectric generators (TEG), aiming to achieve a breakthrough in sustainable energy harvesting from industrial waste heat. The project will develop new infrared-sensitive, low-bandgap (<0.7 eV) TPV cells with integrated plasmonic metamaterials to enhance photon absorption and improve overall heat-to-electricity conversion efficiency to 25%, alongside high-performance TEG devices made from earth-abundant materials with an efficiency of 10%. Using an innovative design strategy, these components will be combined into a modular, hybrid energy harvesting system that can be easily integrated into production lines.
To achieve this goal, INFERNO brings together expertise in materials research, modeling, cell fabrication, thermoelectricity, and electronics on a pan-European scale. The integrated hybrid system and its components (TPV, MetaS, TEG) will be tested in three pilot demonstrations across three countries to convert waste heat into electricity and reduce greenhouse gas emissions.
Objective 1: Demonstrate energy conversion efficiency ηTPV=25% at 800 °C with advanced thermophotovoltaic cell.
Design and process flow of the TPV cell completed. Fabrication of advanced TPV receiver (innovative high quality absorber material, thin film process with back reflector implementation, advanced module technology) has been started and the first version of the TPV cells are expected by end of Feruary 2026.
Objective 2: Demonstrate novel upscaling thermal energy collector to further improve the spectral efficiency by adapting the source to the TPV cell in term of spectral sensitivity and numerical aperture.
Design of the Silicon Metasurfaces is completed and simulation run started, which will be developed and integrated at the input of the device for collimating or spectrally filtering the incident radiation. The first version of the metasurface will be availabe by end of February 2026.
Objective 3: Develop advanced TEG beyond current state of the art with an efficiency of 10% and a power output of 1 W/cm2.
First version of the TEG modules are developed and are now available for testing. These modules are developed based on earth abundant materials for power generation with performances transcending the state-of-the-art using heat sources with temperatures of upto 200 °C. The next target is upto 500 °C.
Objective 4: Design and develop an innovative hybrid INFERNO system to generate 15 kW/m2 electricity.
Design of the innovative hybrid INFERNO system is completed and the first simulation runs are carried out with and positive results. The design of the cooling system has started. The processing methods for building a complete hybrid waste heat to electricity recovery system based on TPV, Meta-surfaces, TEG and heat exchanger technologies will start from month 20 of the project.
Obj. 5 Experimental implementation of pilot demonstrators based on O1, O2, O3 and O4 in three EU (European Union) countries.
Three separate demonstrators will be developed based on 1. TPV + Metasurface demonstrator (in France); 2. TEG demonstrator (in Germany) and 3. Hybrid system demonstrator (in Ireland). The work related to this objective will be started in month 20 of the project.
Design and process flow of the TPV cell completed. Fabrication of advanced TPV receiver (innovative high quality absorber material, thin film process with back reflector implementation, advanced module technology) has been started and the first version of the TPV cells are expected by end of Feruary 2026.
Objective 2: Demonstrate novel upscaling thermal energy collector to further improve the spectral efficiency by adapting the source to the TPV cell in term of spectral sensitivity and numerical aperture.
Design of the Silicon Metasurfaces is completed and simulation run started, which will be developed and integrated at the input of the device for collimating or spectrally filtering the incident radiation. The first version of the metasurface will be availabe by end of February 2026.
Objective 3: Develop advanced TEG beyond current state of the art with an efficiency of 10% and a power output of 1 W/cm2.
First version of the TEG modules are developed and are now available for testing. These modules are developed based on earth abundant materials for power generation with performances transcending the state-of-the-art using heat sources with temperatures of upto 200 °C. The next target is upto 500 °C.
Objective 4: Design and develop an innovative hybrid INFERNO system to generate 15 kW/m2 electricity.
Design of the innovative hybrid INFERNO system is completed and the first simulation runs are carried out with and positive results. The design of the cooling system has started. The processing methods for building a complete hybrid waste heat to electricity recovery system based on TPV, Meta-surfaces, TEG and heat exchanger technologies will start from month 20 of the project.
Obj. 5 Experimental implementation of pilot demonstrators based on O1, O2, O3 and O4 in three EU (European Union) countries.
Three separate demonstrators will be developed based on 1. TPV + Metasurface demonstrator (in France); 2. TEG demonstrator (in Germany) and 3. Hybrid system demonstrator (in Ireland). The work related to this objective will be started in month 20 of the project.
In workpacke 1, a detailed design and model of the hybrid energy harvesting system including comprehensive thermal models have been developed. Recent models of different standalone and hybrid systems accounted for the optical and heat transfer mechanisms. Using both analytical and numerical methods, the models predict temperature profiles and overall system performance under the established design framework. These models were implemented in a first iteration, and the initial simulations have been successfully executed, confirming that the hybrid TPV–TEG–metasurface system can be fully modelled and operational for future detailed analysis and validation.
In workpackage 2, Fraunhofer ISE and University of Troy (UTT) worked on progressing thermophotovoltaic technology. Fraunhofer ISE started fabrication of InGaAs based TPV cells, developed first prototypes of TPV cells based on an advanced strain-balanced multi-quantum well material with reduced bandgap, and progressed implementation of individual TPV cells into modules. UTT studied how meta surfaces can be used to manipulate the infrared emission from a hot source to benefit the different envisioned waste heat recovery system configurations. First prototype designs have been modeled, where the meta material is used as selective emitter.
The workpackage 3 advances high-performance magnesium (Mg)-based thermoelectric materials and devices for efficient energy conversion up to 500 °C. Mg-based compounds provide a sustainable, low-cost alternative to Bi2Te3 but face challenges from oxidation and interfacial degradation. Using atomic layer deposition (ALD), we developed conformal protective coatings that suppress oxidation, improving stability and lifetime. ALD-protected modules outperform Bi2Te3 devices below 200 °C and maintain robust performance up to 500 °C, marking clear progress beyond the state of the art. These results may open new opportunities for high-temperature thermoelectric applications. Key needs for further uptake include material optimization, long-term durability testing, process scale-up, demonstration and market access support, IPR management, and alignment with European standardization and regulatory frameworks to facilitate commercialization.
In workpackage 2, Fraunhofer ISE and University of Troy (UTT) worked on progressing thermophotovoltaic technology. Fraunhofer ISE started fabrication of InGaAs based TPV cells, developed first prototypes of TPV cells based on an advanced strain-balanced multi-quantum well material with reduced bandgap, and progressed implementation of individual TPV cells into modules. UTT studied how meta surfaces can be used to manipulate the infrared emission from a hot source to benefit the different envisioned waste heat recovery system configurations. First prototype designs have been modeled, where the meta material is used as selective emitter.
The workpackage 3 advances high-performance magnesium (Mg)-based thermoelectric materials and devices for efficient energy conversion up to 500 °C. Mg-based compounds provide a sustainable, low-cost alternative to Bi2Te3 but face challenges from oxidation and interfacial degradation. Using atomic layer deposition (ALD), we developed conformal protective coatings that suppress oxidation, improving stability and lifetime. ALD-protected modules outperform Bi2Te3 devices below 200 °C and maintain robust performance up to 500 °C, marking clear progress beyond the state of the art. These results may open new opportunities for high-temperature thermoelectric applications. Key needs for further uptake include material optimization, long-term durability testing, process scale-up, demonstration and market access support, IPR management, and alignment with European standardization and regulatory frameworks to facilitate commercialization.