Search Results (11,179)

The rapid acceptance of solar photovoltaic (PV) energy across various countries has created a pressing need for more coordinated approaches to the sustainable monitoring and maintenance of these widely distributed installations. To address this challenge, several digitization architectures have been proposed, with one of the most recently applied being the digital twin (DT) system architecture. DTs have proven effective in predictive maintenance, rapid prototyping, efficient manufacturing, and reliable system monitoring. However, while the DT concept is well established in fields like wind energy conversion and monitoring, its scope of implementation in PV remains quite limited. Additionally, the recent increased adoption of autonomous platforms, particularly robotics, has expanded the scope of PV management and revealed gaps in real-time monitoring needs. DT platforms can be redesigned to ease such applications and enable integration into the broader energy network. This work provides a system-level overview of current trends, challenges, and future opportunities for DTs within renewable energy systems, focusing on PV systems. It also highlights how advances in artificial intelligence (AI), the internet-of-Things (IoT), and autonomous systems can be leveraged to create a digitally connected energy infrastructure that supports sustainable energy supply and maintenance. Full article

With the high proportion of wind and photovoltaic (PV) power connection in the new electricity system, the system output power volatility is enhanced. When the output fluctuation of the system is suppressed, the pumped storage condition is changed frequently, which leads to the vibration enhancement of the unit and a decrease in the system safety. This paper proposes a pump turbine health evaluation model based on the combination of a weighting method and cloud model in a high proportion wind and PV power connection scenario. The wind–PV output characteristics of the complementary system in a year (8760 h) and a typical week in four seasons (168 h) are analyzed, and the characteristics of frequent working condition transitions of pumped storage units are studied against this background. A five-level health classification system including multi-dimensional evaluation indicators is established, and a multi-level health evaluation based on cloud membership quantification is realized by combining the weighting method and cloud model method. The case analysis of a pumped storage power station within a new electricity system shows that the system as a whole presents typical cloud characteristics (Ex = 76.411, En = 12.071, He = 4.014), and the membership degree in the “good” state reaches 0.772. However, the draft tube index (Ex = 62.476) and the water guide index (Ex = 50.333) have shown a deterioration trend. The results verify the applicability and reliability of the evaluation model. This study provides strong support for the safe and stable operation of pumped storage units in the context of the high-proportion wind and PV power connection, which is of great significance for the smooth operation of the new electricity system. Full article

This work concerns the experimental verification of changes in the energy efficiency of photovoltaic installations through the use of bifacial modules. For this purpose, an experimental stand was designed and built for the comparative analysis of the efficiency of two types of photovoltaic panels: bifacial (bPV) and monofacial (mPV). The tests consisted of placing the panels at different heights above the ground surface and at different angles. During the tests, three substrates with different albedo were taken into account: green grass, gray concrete (fabric), and white snow (polystyrene). The tests for both types of panels were carried out simultaneously (in parallel), which guaranteed the same environmental conditions (temperature and solar radiation intensity). Based on the results of the voltage and current measurements for different angles of PV module inclination and, for bPV panels, different heights above the ground surface and different types of substrate, a series of current–voltage characteristics and power characteristics were plotted. The “additional” energy efficiency of bifacial panels compared to monofacial panels was also determined. It was shown that under favorable conditions, using bifacial panels instead of monofacial panels can increase the production of electricity by more than 56% from structures of the same dimensions. The research results can be of great value when designing photovoltaic installations. Full article

Building-integrated photovoltaic (BIPV) systems present a promising avenue for integrating renewable energy generation into urban environments. However, they pose unique challenges, including higher planning efforts and reduced yield generation compared to conventional rooftop systems. Despite these challenges, the double use of area and the high potential in urban landscapes offer compelling advantages. Modules have become highly customizable to fit architect’s requirements in sustainable yet also aesthetic building material. This paper discusses the results of a “living laboratory” in Berlin, which is both a typical building with a ventilated curtain wall and a unique showcase for BIPV technology. Through careful analysis of various factors, including module positioning, ventilation, and shading, this study demonstrates the feasibility and practicality of BIPV integration. The “living lab” not only highlights the technical viability of BIPV systems but also underscores their potential to enhance architectural aesthetics and promote sustainability and carbon-neutrality in urban landscapes. Full article

The compound energy system is an important component of zero-carbon buildings. Due to the complex form of the system and the difficult-to-capture characteristics of thermo-electric coupling interactions, the operation control of the zero-carbon building’s energy system is difficult in practical engineering. Therefore, it is necessary to carry out relevant optimization methods. This paper investigated the current research status of the control and scheduling of compound energy systems in zero-carbon buildings at home and abroad, selected a typical zero-carbon building as the research object, analyzed its energy system’s operational data, and proposed an operation scheduling algorithm based on day-ahead flexible programming and intraday rolling optimization. The multi-energy flow control algorithm model was developed to optimize the operation strategy of heat pump, photovoltaic, and energy storage systems. Then, the paper applied the algorithm model to a typical zero-carbon building project, and verified the actual effect of the method through the actual operational data. After applying the method in this paper, the self-absorption rate of photovoltaic power generation in the building increased by 7.13%. The research results provide a theoretical model and data support for the operation control of the zero-carbon building’s compound energy system, and could promote the market application of the compound energy system. Full article

PSS (Photovoltaic Solar Systems) are a key technology in energy transition, and their efficiency depends on multiple interrelated factors. This study uses a systematic review based on the PRISMA methodology to identify four main categories affecting performance: technological, environmental, design and installation, and operational factors. Notably, technological advances in materials such as perovskites and emerging technologies like tandem and bifacial cells significantly enhance conversion efficiency, fostering optimism in the field. Environmental factors, including solar radiation, temperature, and contaminants, also substantially impact system performance. Design and installation play a crucial role, particularly in panel orientation, solar tracking systems, and the optimization of electrical configurations. Maintenance, material degradation, and advanced monitoring systems are essential for sustaining efficiency over time. This study provides a comprehensive understanding of the field by reviewing 113 articles and analyzing three key areas—materials, application of sizing technologies, and optimization—from 2018 to 2025. The paper also explores emerging trends, such as the development of energy storage systems and the integration of smart grids, which hold promise for enhancing photovoltaic module (PM) performance. The findings highlight the importance of integrating technological innovation, design strategies, and effective operational management to maximize the potential of PM systems, providing a solid foundation for future research and applications across residential, industrial, and large-scale contexts. Full article

The construction sector is a significant contributor to global greenhouse gas (GHG) emissions, necessitating urgent decarbonization efforts to align with international climate goals such as the Paris Agreement and the European Green Deal. This study explores a comprehensive framework for construction companies to map and reduce their GHG emissions through a structured four-step approach: defining emission scopes, conducting GHG inventories, setting reduction targets, and planning actionable reductions. Four key pathways are proposed: electricity decarbonization through renewable energy adoption and energy efficiency measures; direct emissions reduction via fleet electrification and infrastructure optimization; recycling and resource efficiency improvements through waste diversion and material reuse; and supply chain emissions reduction by enforcing sustainability standards and responsible sourcing practices. The analysis highlights the importance of integrating technological, organizational, and policy-driven solutions, such as rooftop photovoltaic systems, virtual power purchase agreements, waste management strategies, and supplier codes of conduct aligned with global sustainability benchmarks. The study concludes that construction companies can achieve significant emission reductions by adopting a structured, multi-pathway approach; emphasizing progress over perfection; and aligning their strategies with national and international climate targets. This research provides actionable insights for the construction sector to transition toward a net-zero future by 2050. Full article

This work explores the effectiveness of explainable artificial intelligence in mapping solar photovoltaic power outputs based on weather data, focusing on short-term mappings. We analyzed the impact values provided by the Shapley additive explanation method when applied to two algorithms designed for tabular data—XGBoost and TabNet—and conducted a comprehensive evaluation of the overall model and across seasons. Our findings revealed that the impact of selected features remained relatively consistent throughout the year, underscoring their uniformity across seasons. Additionally, we propose a feature selection methodology utilizing the explanation values to produce more efficient models, by reducing data requirements while maintaining performance within a threshold of the original model. The effectiveness of the proposed methodology was demonstrated through its application to a residential dataset in Madeira, Portugal, augmented with weather data sourced from SolCast. Full article

Amid escalating global energy demand and heightened environmental concern, this study presents an innovative photovoltaic–thermal flash-tank vapor injection heat pump (PFVHP). This system integrates a photovoltaic–thermal (PVT) module into a conventional flash-tank vapor injection heat pump (FVHP) to realize simultaneous heating and power generation. Two distinct operation modes are designed for the PFVHP: TS-mode (two-source mode) for most solar radiation conditions and AS-mode (air-source mode) for low- or no-solar-radiation conditions. The energy, exergy, economic, and operational emission performance of the PFVHP are theoretically analyzed and compared with those of the FVHP. The findings reveal that the PFVHP can achieve a maximum cycle and system coefficient of performance (COP) at the respective optimal intermediate pressures. Exergy analysis indicates that enhancing solar radiation helps the PFVHP produce more heat exergy and electricity, but reduces the system exergy efficiency. As the evaporating temperature ranges from −20 °C to 5 °C, the cycle COP and system COP of the PFVHP are, respectively, 8.5% to 6.3% and 50.0% to 35.2% higher than the COP of the FVHP. The exergy flow comparison demonstrates that the PFVHP significantly enhances the system performance by reducing the overall exergy loss in devices excluding a PVT module, benefiting from the absorption of solar exergy by the PVT module. Economic and operational emission analyses indicate that the PFVHP offers a payback period of 9.38 years and substantially reduces the air pollution emissions compared to the FVHP. Full article

Solar photovoltaic (PV) systems in buildings must comply with both electrotechnical standards for module safety and local building codes, which typically do not address their electrical nature. This regulatory gap creates challenges in assessing the fire performance of PV systems. This paper presents a procedure to adapt a common test method used in some building codes to assess external fire conditions for roofs, while maintaining operative PV modules. Two configurations were tested: an organic PV thin film on a metallic sandwich panel and a glass–glass-encapsulated organic PV module. The tests were conducted under high voltage and current conditions to simulate the systems’ behavior within a larger PV array. Significant electric arcs were observed during testing of the metallic sandwich panel configuration without glass protection when subjected to high voltages or currents. In these cases, total heat release increased by at least 30% compared to non-electrically loaded scenarios or glass-insulated PV modules, likely due to a greater damaged surface area. Electric arcs created new ignition sources, damaging whole PV modules, whereas in the case with no electrical load, propagation flames advanced toward both the upper edge and the corners of the sample, ultimately damaging the entire triangular area above the fire source. The results indicate that the electrical characteristics of PV systems can significantly impact external fire spread behavior. The study identifies challenges in maintaining system activity during testing and simulating real scenarios and proposes for future research directions. Full article

Energy efficiency represents a strategic priority in both Italian and European legislation to mitigate the energy consumption of buildings, which are significant contributors to greenhouse gas emissions. Currently, about 75% of the EU building stock is considered to be energy inefficient and requires substantial retrofitting. This study examines the energy redevelopment of a large building complex, which currently has an energy class E label. The aim is to achieve a significant improvement in energy efficiency and reduce fossil fuels usage, in line with sustainability standards. The intervention includes replacing the existing air-conditioning and heating systems with high-efficiency air-to-water heat pumps, powered by electricity generated, in part, by an integrated photovoltaic system. Through the analysis of available technological solutions and the application of a Building Information Modeling (BIM) methodology, the research proposes strategies to optimize the energy efficiency of buildings while minimizing the environmental impact and ensuring compliance with current regulations. The results highlight the effectiveness of such approaches in supporting the energy transition, with the implemented measures reducing the non-renewable energy demand from 191,684 kWh/m²/year to 76,053 kWh/m²/year. This led to a decrease in CO₂ emissions of 604 tons/year, representing a 78% reduction compared to initial levels, a clear contribution toward achieving European sustainability goals. Full article

The post-use management of plastic films, including shrink films, poses a significant environmental and technological challenge for the industry. Due to their durability and difficulty in degradation, these wastes contribute to environmental pollution, generating microplastics and greenhouse gas emissions during improper disposal. This paper examines different post-use management methods for shrink wrap, such as recycling, landfilling, and incineration, and assesses their impact on the environmental impact of the bottle packaging process using a life-cycle analysis (LCA). This study shows that the recycling option has the lowest potential environmental impact. Compared to other post-use management options, recycling reduces the potential environmental impact by more than 50%. The analysis also shows that the tested scenario using recycled film and photovoltaic energy has the lowest potential environmental impact. Using recycled film and powering the process with renewable energy reduces the potential environmental impact by about 95% compared to Scenario 1 and by about 85% in Scenario 3. Full article

High-stability photovoltaic devices are crucial for low-power or passive applications in fields such as renewable energy, wearable electronics, and deep-space exploration. However, achieving stable and controllable doping in two-dimensional (2D) materials remains challenging, hindering the optimization of photovoltaic performance. Here, we fabricate three high-performance, self-driven photodetectors based on layered WSe₂ with varying doping concentrations. By leveraging asymmetric Schottky barriers and introducing a defect-free, high-bandgap intrinsic region with a long mean free path, we construct a positive–intrinsic–negative (PIN) vertical homojunction that significantly enhances the photogenerated voltage, photon absorption, and carrier transport efficiency. The resulting PIN junction exhibits a photogenerated voltage of up to 0.58 V, a responsivity of 0.35 A/W, and an external quantum efficiency of 83.9%. Moreover, it maintains a reverse saturation current as low as 0.2 nA at 430 K. These results provide a promising route toward the development of high-responsivity, high-stability van der Waals devices and highlight the potential for 2D material-based technologies to operate reliably under extreme conditions. Full article

The removal of surface residues from single-layer graphene (SLG), including poly(methyl methacrylate) (PMMA) polymers and Cl⁻ ions, during the transfer process remains a significant challenge with regard to preserving the intrinsic properties of SLG, with the process often leading to unintended doping and reduced electronic performance capabilities. This study presents a rapid and efficient surface treatment method that relies on an aqueous sodium nitrite (NaNO₂) solution to remove such contaminants effectively. The NaNO₂ solution rinse leverages reactive nitric oxide (NO) species to neutralize ionic contaminants (e.g., Cl⁻) and partially oxidize polymer residues in less than 10 min, thereby facilitating a more thorough final cleaning while preserving the intrinsic properties of graphene. Characterization techniques, including atomic force microscopy (AFM), Kelvin probe force microscopy (KPFM), and X-ray photoelectron spectroscopy (XPS), demonstrated substantial reductions in the levels of surface residues. The treatment restored the work function of the SLG to approximately 4.79 eV, close to that of pristine graphene (~4.5–4.8 eV), compared to the value of nearly 5.09 eV for conventional SLG samples treated with deionized (DI) water. Raman spectroscopy confirmed the reduced doping effects and improved structural integrity of the rinsed SLG. This effective rinsing process enhances the reproducibility and performance of SLG, enabling its integration into advanced electronic devices such as organic light-emitting diodes (OLEDs), photovoltaic (PV) cells, and transistors. Furthermore, the technique is broadly applicable to other two-dimensional (2D) materials, paving the way for next-generation (opto)electronic technologies. Full article

The rapid integration of renewable energy sources, such as photovoltaic power systems, has reduced the necessary for synchronous generators, which traditionally contributed to grid stability during disturbances. This shift has led to a decrease in reactive power reserves (RPRs), raising concerns about voltage stability. Real-time monitoring of voltage stability is crucial for transmission system operators to implement timely corrective actions. However, conventional methods, such as continuation power flow calculations, are computationally intensive and unsuitable for large-scale power systems. Machine learning techniques using data from phasor measurement units have been proposed to estimate voltage stability. However, these methods do not consider changes in generator operating conditions and fluctuating RPRs. As renewable energy generation increases, the operating conditions of generators vary, which leads to significant changes in system RPRs and voltage stability. In this paper, a voltage stability margin is proposed using regression trees with RPRs varying based on generator operation conditions. Simulations based on the IEEE 9-bus system demonstrate that the proposed approach provides an accurate and efficient voltage stability estimation. Full article