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Spatial Distribution of Reflectance Measurement for Solar Materials
Full text linkThe spatial distribution of the reflected radiation by solar materials is a really important characteristic to be measured in order to obtain realistic optical simulation of solar systems. However, most of the instruments measure the hemispherical component of the reflected flux from materials. This study presents a new equipment composed of a semi-sphere with 62 detectors which measure the spatial distribution of reflectance from any material used in solar systems. The first tests and checking with this instrument have been presented in this paper
Understanding Hydrogen Passivation Mechanism in poly-Si Passivating Contacts via SixNy Composition: Insights From Effusion Studies
Full text linkTunnel Oxide Passivated Contact (TOPCon) cell performance relies significantly on hydrogen for its passivation of defects. In this paper, we discuss the temperature dependent effusion of hydrogen from the silicon nitride (SixNy) layers deposited on top of poly-Si/SiO2 passivated contacts. Silicon content in SixNywas varied by silane/ammonia flow ratio. FTIR shows significant N-H stretching & bending peaks for nitrogen-rich SixNy layer compared to silicon-rich SixNy layer, and few Si-H bonds compared to silicon-rich SixNy. During effusion, the N-H bonds in N-rich SixNy layer break to provide H2 , NH3 and N2, resulting in stoichiometry change. Negligible effusion of nitrogen occurs for Si-rich SixNylayers. Next, we investigate the mechanism of hydrogen passivation on symmetrical i-poly-Si/SiO2/i-poly-Si structures with different hydrogenating layers namely Si-rich SixNy , Al2O3 and a stack of Al2O3/SixNy, and conclude that a thin 15nm Al2O3 enables the best passivation. We also discuss the possibility of H diffusion in molecular H2 form, most suitable for SiO2 interface passivation, while the atomic hydrogen enables both passivation and de-passivation of interface dangling bonds
Overcoming Data Scarcity in Calibrating SUMO Scenarios With Evolutionary Algorithms
Full text linkTraffic simulations play a crucial role in urban planning and mobility management by providing insights into transportation systems. However, their effectiveness heavily depends on accurate demand calibration, often requiring large amounts of observational data. This poses a challenge in settings with limited data availability. In this paper, we propose a methodology for calibrating SUMO scenarios under data-scarce conditions. To contextualize our approach, we first review existing SUMO scenarios and their demand calibration strategies. We then introduce the Mannheim SUMO Traffic Model (MaST) as a case study and employ the Covariance Matrix Adaptation Evolution Strategy (CMA-ES) to optimize route probabilities as input for the existing routeSampler tool provided by SUMO. Results indicate that our method significantly improves calibration accuracy compared to baseline approaches both for 3-hour and 24-hour scenarios. While our findings suggest that the proposed methodology can support demand calibration in data-limited environments, further research is needed to assess its generalizability and effectiveness in different contexts
Digital Twin-Aided Municipal Traffic Control
Full text linkSwift advances in computing and artificial intelligence (AI) technologies of late have prompted the increasing applications of digital twins (DiTs) to various sectors for boosting effectiveness and productivity. DiTs have been envisioned to possess immense potential for transforming numerous domains and sectors in the recent report of National Academics due to their powerful real-time decision-making based on modeling and simulating physical systems. This paper deals with a novel design of digital twin-aided municipal traffic control (DiTAT) for best traffic management over a targeted municipal region, based on real-world traffic video imagery gathered by available roadside surveillance cameras. DiTAT analyzes sequences of video frames to extract traffic volume details, including the start time, speed, incoming zone, and outgoing zone of every vehicle in existence. Being DiT-based, DiTAT employs the automated, open-source traffic simulator (SUMO) as the digital twin of the physical roadway configuration over the target region to try various traffic light control settings under the extracted traffic volume details for identifying the most favorable setting. The identified setting is then sent to the physical roadway traffic lights for realization to manage traffic during the next time window, when its resulting traffic is simulated by SUMO again to get the best setting for the subsequent time window reactively. This process repeats continuously window by window, with a bidirectional interplay between SUMO simulation and physical traffic for the target region. DiTAT is demonstrated to lift transport performance under real-world traffic scenarios
SUMO Simulation of DLR\u27s Research Intersection
No full textTrajectory data are great data to work with, since they are the most natural data for traffic. However, they provide considerable challenges when tried to put into a micro-simulation framework such as SUMO. This work here gives an example what had to be done to arrive at a simulation that is driven by these data. Succeeding in this, microscopic tools can be much better tested against real data
Feasibility of AgriVoltaic Wheat Farming with Standard-Height, Utility-Scale Tracking Systems
Full text linkThis research focuses on AgriVoltaic systems, combining standard-height (1.5 meters) PV arrays with single-axis solar trackers for wheat cultivation. The study was conducted in Sorocaba/São Paulo, at the Nextracker Solar Study Laboratory situated at Flextronics Institute of Technology (FIT). This study reveals that wheat production between PV rows is minimally affected by shading. In the 2023 winter wheat season in Brazil, the production in Regular Agriculture was 12.04 ± 4.27 tons/ha. In the AgriVoltaics area, it produced 10.72 ± 1.52 tons/ha of wheat in addition to 2354.82kWh/kWp-year. In the area dedicated to energy production, it generated a performance of 2462.26kWh/kWp-year. Statistically, using the Tukey’s test, it is possible to state that there is no difference in productivity, although there are differences in morphological and physiological performance, issues that should be better explored in future studies. Furthermore, AgriVoltaics systems observed a 40% reduction in irrigation requirements, making it economically feasible for both energy providers and local farming economies. So, this study demonstrates successful integration of cost-effective PV trackers, offering potential for large-scale co-production of food and renewable energy
FDO Testbed
Full text linkA project has beenstarted to create a distributed testbed based on FDOs and using the DOIP protocol. This paper describes the intentions and the required components to build such a testbed. It can beseen as a first step towards an international FDO testbed
Lessons Learned from Three Agrivoltaic Installations in New Jersey
Full text linkAgrivoltaics is a new technology that has the potential to positively impact commercial farming by combining agricultural practices with the generation of solar energy. While some yield reduction is to be expected, resulting from less sunlight reaching the plant canopy and ground occupied by support structures, the generated electricity provides a low-risk supplemental income to farmers. In order to combine farming with electricity generation, agrivoltaic systems use a lower ground coverage ratio compared to normal solar farms and the PV panels are often mounted higher above the ground in order to facilitate the movement of agricultural equipment and to reduce the contrast between shaded and non-shaded areas.
With funding provided from the state of New Jersey and the New Jersey Agricultural Experiment Station (NJAES), we designed and installed three unique agrivoltaic research systems at Rutgers/NJAES farms. These projects were recently completed and are generating electricity that is exported to the grid. This paper discusses the lessons we have learned along the way, including all the steps necessary to see an agrivoltaic project through to completion
Transforming Risk Perception and Fostering Cooperatively the Agri- PhotoVoltaics Technology With Farmers in Five Countries: A Sociological Perspective From the REGACE (Crop Responsive Greenhouse Agriphotovoltaics System With CO2 Enrichment for Higher Yields) Project
Full text linkThe interaction between agricultural practitioners and innovative technologies has emerged as a critical area of inquiry in contemporary academic discourse. Disruptive advancements in agricultural technology—particularly in the domains of drone applications, artificial intelligence (AI), and agrivoltaics—present significant potential to address urgent environmental and energy-related challenges. However, the successful adoption and integration of these technologies are contingent upon robust processes of societal acceptance and comprehension, especially among farmers, who constitute the primary users and key stakeholders. The theory of disruptive innovation, initially conceptualized by Bower and Christensen in 1995, underscores the transformative capacity of novel technologies across various sectors. Nevertheless, the efficacy of such innovations is predicated on their seamless integration and acceptance by diverse stakeholder groups, including primary actors such as farmers and industry, as well as secondary entities with ancillary interests. For technological innovations to achieve their intended outcomes, they must be accompanied by authentic participatory processes that involve end-users from the initial stages. Within this framework, next-generation agriphotovoltaics greenhouses—which integrate photovoltaic systems with agricultural practices and enhance soil CO₂ enrichment—represent a pivotal solution for reconciling agricultural productivity with renewable energy generation. The WP6 of Regace Project. In this perspective, the WP6 of the REGACE project aimed, through the use of mixed qualitative, quantitative, and participatory methodologies, to investigate farming communities’ perceptions of agriphotovoltaics innovations. These sociological processes are intended to accompany the phases and models of agriphotovoltaics innovation from a perspective of social sustainability, with an active involvement of the community of innovation recipients
Sheep Grazing Impacts on Soil Health and Pasture Quality at Commercial Solar Sites in Northeastern USA: Solar Sheep Grazing and Site Conditions
Full text linkAs solar sheep grazing continues to gain traction, it is important to emphasize soil health and pasture quality. Therefore, this study was performed to collect in-field data from 28 grazed and 3 non-grazed commercial solar sites to determine how grazing influences solar site health, associated ecosystem health, forage nutritive quality, and pasture conditions at Northeastern United States of America solar sites from 2022-2024. The majority of the selected sites were previously cropland. Construction of sites was between 2015-2020 with local graziers later joining the operation to create agrivoltaic systems. Sites were selected by their ability to contribute to the knowledge base over the duration of the study, provide relevant information about innovative co-location strategies and the willingness of all parties involved in the solar site maintenance to share information. Solar grazed sites tended to (p=0.06) have higher soil organic matter than non-grazed sites, with values of 4.14% and 3.70% respectively. Soil pH was significantly higher (p=0.01) in grazed sites, with an average of 6.20 compared to 5.81 in non-grazed sites, demonstrating the potential for solar grazing to improve solar site soil health. Crude protein was consistently significantly higher (p<0.001) in under panel areas for all seasons and years, while better digestibility was seen in under panel areas in Fall 2023. While not statistically significant (p=0.07), pasture condition scores increased between 2022 and 2023, suggesting that sheep grazing may have the potential to improve solar site pasture quality over time. Overall, solar sheep grazing helps to create a beneficial dual-use environment