• Energy Research
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Fungi are crucial for terrestrial ecosystems, yet the role of fungal diversity in ecosystem functions remains unclear. We synthesize fungal biodiversity and ecosystem function (BEF) relationships, focusing on plant biomass production, carbon storage, decomposition, and pathogen or parasite resistance. The observed BEF relationships for these ecosystem functions vary in strength and direction, complicating generalizations. Strong positive relationships are generally observed when multiple ecosystem functions are addressed simultaneously. Often, fungal community composition outperforms species richness in predicting ecosystem functions. For more comprehensive fungal BEF research, we recommend studying natural communities, considering the simultaneous functions of a broader array of fungal guilds across spatiotemporal scales, and integrating community assembly concepts into BEF research. For this, we propose a conceptual framework and testable hypotheses.

The mechanical stability of interconnections in solar modules is crucial for their long-term performance. Electrically conductive adhesives (ECAs) offer a promising solution for the interconnection of perovskite-silicon tandem (PVST) solar cells due to their low-temperature processibility. In this study, the influence of low curing temperatures on the mechanical and electrical properties of ECAs was investigated to assess their suitability for PVST technology. Four commercially available ECAs were characterized, focusing on curing temperatures of 100 °C, 140 °C, and 180 °C. Mechanical characterization through tensile tests and dynamic mechanical analysis (DMA) revealed varying Young’s modulus (E) (stiffness) and glass transition temperatures (TG) among the ECAs. Electrical characterization showed that lower curing temperatures generally led to lower volume resistivity, particularly for ECA C. However, joint resistance values exhibited high standard deviations. Void analysis indicated that void formation had a negligible effect on the mechanical properties of ECAs. Furthermore, the influence of curing degree on mechanical and electrical properties was investigated, highlighting the importance of complete curing for achieving desired properties. Overall, this study provides valuable insights into optimizing the interconnection process for PVST solar cells, essential for enhancing the long-term stability and performance of solar modules

Recombination at the metal-silicon interface is a major barrier to reaching the theoretical power conversion efficiency limits. We present a PL method for evaluating the metal contact recombination current (J0,c) of rear TOPCon metallisation.

ABSTRACTFor high‐efficiency solar cells, such as Si‐III‐V tandem solar cells, implementing narrow contact fingers is essential for achieving optimal conversion efficiencies. By achieving narrower contact fingers without compromising electrical performance, more sunlight reaches the active areas of the cell, thus reducing front‐side shading and enhancing overall energy conversion efficiency. In this work, we demonstrate a proof of principle for a novel low‐temperature metallization process using glass stencils to print ultra‐fine line contacts. The narrowest contacts achieved have a width of = 8.4 ± 1.3 with an aspect ratio of = 0.19 ± 0.05. Through optimization described in this work, contact fingers with = 9.7 ± 0.6 μm and a substantially greater aspect ratio of = 0.45 ± 0.1 could be achieved. To realize these ultra‐fine line fingers, glass stencils with tailored aperture channels were realized using a two‐step laser induced deep etching (LIDE) process that enables complex three‐dimensional aperture channel geometries.

Light and elevated Temperature Induced Degradation (LeTID) is likely causing strong yield losses in a significant number of photovoltaic (PV) power plants which were commissioned in the late 2010s. In this work, a procedure for an in-field recovery using overnight current injection to trigger temporary recovery of LeTID is presented. The general feasibility of such a procedure is first demonstrated by climatic chamber experiments on strongly degraded mc-Si PERC PV modules. Within the screened test conditions, a temporary recovery procedure with high currents and low module temperatures is most promising for an economic application in PV power plants. An outdoor experiment with current injection during nights and MPP tracking during days confirmed the possibility to recover LeTID in PV power plants. By injecting a pulsed current, the heating of the modules caused by the current injection was strongly reduced compared to the heating at constant current injection. Recommendations for the application of a procedure in PV power plants are given based on the required energy expenditure and cost.

As a major contributor to overall carbon emissions and energy consumption, the housing sector has great potential to reduce energy consumption, whether by reducing the number of appliances, heating temperature or floor space. Consumption patterns encompass how people choose and consume products that satisfy their needs and wants. However, wants, and to some extent needs, are influenced by various factors and existing material and non-material (infra)structures, especially in the housing sector. Focusing on the floor area, this article aims to identify potentials towards lower consumption lifestyles by applying the Avoid-Shift-Improve framework in the residential sector. Through a conceptual review, the article explores what shapes current patterns of space use and outlines potential future pathways. Starting from the macro level, the article examines existing and emerging (societal) trends with (potential) impacts on housing consumption. It then looks at the structural development of households affected by the studied trends. At the micro level, the article provides an overview of the potential impact of individual behaviour on space use patterns within different categories of housing behaviour. The article identifies the potential for social and technical change in the housing sector and concludes that promoting non-materialistic narratives (avoid), offering alternative and innovative solutions to satisfy people’s spatial needs (shift) and designing flexible buildings (improve) appear to be effective ways for fostering behavioural change towards more efficient use of space.

This report explores the development of a framework and indicators for monitoring transitions in European food systems, highlighting systemic changes essential for sustainability. Using a scoping study approach, it evaluates 18 selected indicator frameworks to identify key elements, relationships, and sustainability considerations. The study emphasises the need for comprehensive frameworks that encompass environmental, social, and economic dimensions while addressing gaps such as feedback loops, cross-system interactions, and governance structures. Concrete proposals for indicators are provided, complemented by expert-driven recommendations to fill data gaps. The report also offers broader lessons for improving sustainability transition monitoring, including integration with policy and actor relations. Insights aim to support the advancement of food systems monitoring and inform future European environmental reporting. Framework Partnership Agreement Concerning the European Topic Centre on Sustainability Trends (2022-2026) OCP/EEA/CAS/21/007-ETC ST

Within this work, we present key results of the transnational European research project “Bussard”. The aim of this project is the development and evaluation of various innovative approaches for highly efficient cell concepts such as tunnel oxide passivating contact (TOPCon) solar cells considering the whole process chain including front-end, back-end and module processing. We present atomic layer deposition (ALD) as a high-throughput alternative for the deposition of Al2O3 passivation layers on the front side of TOPCon solar cells enabling a substantial reduction of the emitter saturation current density down to j0e = 13 fA/cm2. In the field of metallization, we evaluate and demonstrate three innovative approaches for the fine-line metallization of TOPCon solar cells. In this study we focus on multi-nozzle parallel dispensing, a technology that was developed as an alternative to standard screen-printing metallization and is used for the metallization of TOPCon solar cells for the first time. By optimizing the fabrication process at Fraunhofer ISE, we realize TOPCon solar cells (156.75 mm × 156.75 mm) with a champion conversion efficiency of up to ηmax = 24.2% (independently confirmed by Fraunhofer ISE CalLab PVCells). Finally, we present a comprehensive evaluation of the innovative Tape Solution interconnection concept for TOPCon cells and modules. We demonstrate the feasibility on small-scale and full-format modules and analyze the I–V results as well as cell-to-module (CTM) loss analysis using the simulation tool SmartCalc®. The results are compared to TOPCon modules interconnected via SmartWire Connection Technology (SWCT) and electrically conductive adhesive (ECA).