Periodic Reporting for period 3 - Tech4Win (Disruptive sustainable TECHnologies FOR next generation pvWINdows)
Reporting period: 2021-07-01 to 2022-12-31
The main objective of the project is to develop a set of transparent PV window prototypes (Small and Medium sizes) with strong improvements in level of transparency and visual quality in the visible region, energy generation, advanced filtering capacities, thermal behavior and energy impact. The proposed solution will avoid the use of critical raw materials ensuring the absence of potential problems for the future supply of the raw materials and allowing for a sustainable transfer to mass production levels.
The results obtained have allowed to demonstrate new proof of concept semi-transparent devices that include first oxide-based UV solar cells and IR-selective organic solar cells and modules. The project has also demonstrated the scalability of the processes with the achievement of 30x30 cm2 window prototypes including functional IR modules with long term stability, using industrial lamination processes. These results set the basis for a future building-integrated photovoltaics (BIPV) product portfolio by the development of next generation semi-transparent BIPV non-intrusive elements with very high optical quality
• Definition of requirements and specifications of the glazing system proposed for the Tech4Win window, including the analysis, selection and quantification of the key parameters to design and warranty the performance of the Tech4Win glazing system and the identification and analysis of main standards, regulations and technical codes;
• Development of semi-transparent OPV devices using polymers compatible with stability and industrial requirements, with the demonstration of solar cells with PCE 4.55% - 5.04% and AVT 41% - 59%, and the demonstration of optimized DBR’s allowing a relative increase of 5%-6% of PCE. Durability studies of the active layers performed under 1 sun illumination conditions show fulfillment of stability targets (relative PCE degradation < 15% after 1000 h) when using UV filters developed in the project;
• Development and UV multifunctional ZnO and Zn(S,Se) coatings free of CRMs with band gap > 2.6 eV, high transparency (AVT in range 65% - 70%) and UV filtering > 99%;
• Demonstration of first proof of concept UV selective Zn(S,Se) solar cells with AVT = 69% and PCE = 0.5%.
• Demonstration of alternative ZnO/a-Si cell devices with PCE between 0.6% and 2% and AVT values ranging of 65% and 35%, respectively. Design of optimal device architecture with estimated PCE = 2.5% and AVT 40%
• Multifunctional modelling of the UV and IR selective devices and of the Tech4Win window configurations, including: i) Implementation of optical models for the simulation of the Tech4Win window structure integrating the UV and IR selective devices, the DBR and the different glass panes and encapsulant layers for optical and aesthetic optimization; and ii) Definition and implementation of the BIPV widow subroutines for the modelling of the passive window properties in representative building cases (residential, offices);
• Prototype implementation and demonstration, including: i) development in ASPF of first RtR module devices transferring the processes developed at lab level; and ii) definition of lamination processes at Onyx using IR and UV test devices representative of the final device configurations, with the demonstration of the stability of the OPV laminated devices under 1000 h DHT conditions. Demonstration of 30 x 30 cm2 laminated IR modules with CRI = 89, AVT = 42% and PCE = 2.75%;
• Development of a systematic LCA and LCC analysis.
• Dissemination and communication activities have been developed according to the PDER that was defined at the early stage of the project, adapted to the restrictions imposed by the Covid pandemic situation, including the launching of the project website and social media channels, two promotional project video, three Newsletter issues, the organization of two workshops (virtual, hybrid) on Transparent PV and the presentation of relevant project results at highly recognized International Conferences and scientific journals;
• At Exploitation level, the IPR and Knowledge management strategy has been defined according to the background of each partner, the ownership of the foreground identified and the exploitation agreements among the parties involved. On the other hand, first versions of the Tech2Market analysis and Feasibility Study and Exploitation Strategy for all knowledge created in the project have been accomplished and have been constantly updated according to the project progress. The Feasibility Study has already been continuously updated.
• Demonstration of a first proof of concept of UV selective functional solar cells based in the integration of Zn(OS) nanometric layers showing a very high transparency (up to 75%) and optical quality;
• Development of new device architectures based in the integration of a-Si nanometric layers in oxide based heterostructures with the achievement of devices with photovoltaic conversion efficiencies up to 2% and transparency in the range 35% - 60%. Optimisation of the device architecture shows the possibility to increase the efficiency up to 2.5% when combining optimal electron and hole transport layers;
• Demonstration of new IR selective organic solar cells based in the use of stable and industrial compatible polymers with photovoltaic conversion efficiencies up to 5% and transparency in the range 41% - 59%;
• Demonstration of the scalability of the processes up to 30 x 30 cm2 size, with the development of functional IR modules with transparency 43%, efficiency 2.75% and high optical quality (CRI = 89) using Roll to Roll industrial processes;
• Integration of developed modules in first window prototypes adapting industrial lamination processes. Demonstration of the long term stability (projected lifetime ≥ 20 years) of prototypes integrating functional IR modules;
• Development of new software tools for the simulation of the impact of the solar windows and semi-transparent BIPV elements in buildings. Simulations performed in different kind of buildings (residential and office buildings) located in different climatic regions (corresponding to cold, mild and hot weather conditions) show in all cases an improvement of the building energy balance, which is relevant in the case of hot-mild weather conditions;
• Development of a systematic LCA and LCC analysis, leading to an estimated cost in the range of 225 €/m2, with energy payback times down to 1.7 years for optimal weather conditions