About the Project

€ 1.076.750,00

6 Partners from 5 Countries

Project Objectives

TRANSMIT tackles the challenge of integrating clean energy into buildings with aesthetically pleasing, high-performance, semi-transparent photovoltaics (STPV). This innovative approach utilizes micro-striped solar cells fabricated from two promising materials: mature and stable CIGS and next-generation Perovskite.

We aim at achieving viable stage TRL5 technology within 3 years by tackling specific objectives:

  • Develop a micro-structuring process to create semi-transparent solar cells with a range of average visual transparency (30-70%).

  • Fabricate and validate CIGS and Perovskite-based STPV mini-modules (5x5 cm² and 10x10 cm², respectively), achieving 8% efficiency and 50% transparency. 

The project goes beyond efficiency and aesthetics. We will assess the environmental impact (life-cycle analysis, CO2 emissions) and economic viability (life-cycle costing). Additionally, the project will analyze the impact on building energy use and thermal comfort.

 

Challenges addressed, and approach defined to go beyond the state-of-the-art: 

Current STPV solutions are either view impeding or have an inherent color, making them unattractive for building integration. TRANSMIT tackles this by creating micro-striped solar cells separated by transparent gaps, allowing control over visible light transmission (AVT) and power conversion efficiency (PCE).

Unlike existing solutions, TRANSMIT doesn't sacrifice efficiency for transparency. By using full-thickness solar cells, we achieve high PCE while maintaining color neutrality. Also, the micro-stripes are designed to be indistinguishable from the human eye at typical viewing distances. We will pattern materials in a novel way, leveraging their strengths like CIGS' stability and Perovskite's efficiency potential. This avoids the limitations of existing approaches, such as light absorber thinning or unwanted colouration. We aim to achieve STPV devices with PCE and Light Utilization Efficiency (LUE) that exceed current records and offer beautiful and clean energy solutions for buildings.

 

Results and impact expected:

TRANSMIT will create validated, high-performing, semi-transparent devices (TRL5). These will offer a new aesthetically pleasing solution for intuitively integrating PV into building windows, considering the user's maximum comfort. These features position them to be attractive for both scientific and commercial sectors.

Scientific impact: the dissemination will foster collaboration within the scientific community and leverage research infrastructure.

Commercial impact: combining high PCE and aesthetics makes these windows commercially viable, potentially becoming a building block for the construction industry.

 

Social impact: 

TRANSMIT will assess user experience and social acceptance, considering the perspectives of architects, designers, and vulnerable groups.
To maximize impact, we will share findings with relevant stakeholders (architects, engineers, manufacturers) and participate in key events.

  • Solar cell technology is experiencing tremendous advancements, greatly impacting the development of Building-integrated Photovoltaics (BIPV).

    The segment is growing extremely fast and promises a solution for on-site renewable electricity, enabling zero-energy buildings.

    Simultaneously, Semi-transparent Photovoltaics (STPV) is an emerging technology that adds to windows power-generating capabilities, complementing existing BIPV technologies.

    STPV integration into roofs and façades provides cost-effective energy solutions since those modules can substitute building envelopes and façade elements, such as glass windows.

    In addition, windows make up a large percentage of modern building real estate, hence representing a drastic increase in the available area for on-site electricity generation.

    PV windows combine three functionalities:

    • (i) As building blocks, they transmit sunlight into the building;

    • (ii) As power generators, they convert solar energy into electricity;

    • (iii) As thermal regulators, they block infrared radiation, reducing undesired heating.

    However, currently available STPV technologies provide low performance or unpleasant coloured or disturbed viewing experience.

    In TRANSMIT, we will perform spatial segmentation of solar cells in the form of micro-stripes indistinguishable from the human eye, separated by clear glass, thus allowing light transmission.

  • In cities, glass surfaces are ubiquitous and represent valuable real estate for STPV for clean electricity generation.

    However, the adoption of this technology depends on its ability to be transparent enough (i.e., with high transmission of the visible light spectrum) coupled with a reasonably high power conversion efficiency.

    We propose a high-efficiency semi-transparent photovoltaic (STPV) device that can be deployed in any building with glass windows and façades. With this technology, buildings will be able to generate on-site the electricity they consume and decrease the consumption of electricity generated by fossil fuel sources, thus accelerating the clean energy transition.

  • 1. To develop a micro-structuring process for CIGS to demonstrate semi-transparent solar cells with selected AVT between 30 and 70% (TRL13). The prototype will demonstrate the technology's basic functionality under realistic conditions;

    2. To develop a buffer layer for CIGS solar cells with a non-toxic oxide with high transparency (> 90%);

    3. To develop a micro-structuring process for Perovskites to demonstrate semi-transparent solar cells with selected AVT between 30 and 70% (TRL23). The prototype will demonstrate the technology's basic functionality under realistic conditions;

    4. To achieve a CIGS-based STPV mini-module (5×5 cm2) with 8% efficiency and AVT = 50%, validated in an outdoor environment (TRL5);

    5. To achieve a perovskite-based STPV mini-module (10×10 cm2) with 8% efficiency and AVT = 50%, validated in an outdoor environment (TRL5);

    6. To perform indoor characterization and outdoor testing and assess the performance and degradation of the developed STPV solar cells and mini-modules, as well as the end-user experience;

    7. To perform life-cycle analysis, life-cycle costing, and recycling assessment for the material’s efficient fabrication process;

    8. To perform simulation-based impact assessment regarding building energy performance, operational CO2 emissions and thermal comfort; 9. To perform a socio-economic impact assessment using qualitative and quantitative methods.

  • We will use two PV technologies with efficiencies superior to 20% in their opaque form:

    • (i) Thin-film Cu(In,Ga)Se2 (CIGS) solar cells – in which we will microstructure CIGS on glass using photolithography, sputtering, and lift-off techniques;

    • (ii) Halide perovskites have the prospects of being the next-generation PV technology, in which we will print the perovskite material and use laser ablation to make clear micro-lines, thus creating transparency.

  • Our design philosophy is based on micro-striped solar cells, indistinguishable from the human eye and separated by a fully transparent gap, rendering a highly transparent device. These devices are a novel trend in the Building Integrated Photovoltaics (BIPV) sector, and we aim to develop mini-modules with improved aesthetics and PCE compared to the state-of-the-art.

    Device performance assessment, characterization, and outdoor testing will be performed, as well as life-cycle analysis, life-cycle cost, and screening future potential from sustainability and economic aspects.

    Our approach will be focused on scalable fabrication methods aiming at eventual device maturity, especially regarding upscaling and cost, targeting the BIPV market needs.

    Ultimately, the project will result in micro-striped semi-transparent photovoltaic devices validated in a relevant environment, thus proposing working solar cells and mini-modules at TRL5.

  • TRANSMIT is divided into 7 work packages.

    WP1 is dedicated to project management.

    WP2-WP4 are technical work packages.

    WP2 concentrates on the microstructuring of CIGS solar cells.

    WP3 on the microstructuring of Perovskites.

    WP4 supports WP2-WP3 by providing advanced characterization and indoor and outdoor testing and simulating building performance assessment.

    WP5 will provide an analysis of Life Cycle Assessment and Life Cycle Costing.

    WP6 deals with communication, dissemination, and exploitation.

    WP7 is dedicated to Knowledge community activities and Reporting.