Molecular photoswitches are chemical systems that can undergo reversible chemical transformations following the absorption of light. Such systems find potential application in modern technologies such as molecular electronics, optical data storage, exploitation of solar energy, and much more. In this paper, we present ab initio nonadiabatic molecular dynamics of the dicyano phenyl-substituted dihydroazulene/vinylheptafulvene (DHA/VHF) system using ab initio multiple spawning in combination with state-averaged α-complete active space self-consistent field theory to study the photoinduced electrocyclic ring opening reaction that converts DHA to VHF. Scrutinizing the mechanism of the photoinduced ring opening reaction is crucial to be able to design new derivatives with improved properties and to design experiments that can probe the photoswitching of such systems. Our simulations show that this DHA system photoswitches with a 41% quantum yield on a sub-picosecond time scale. In addition to that, we simulate the time-resolved photoelectron spectrum, which, by comparison to the experimental equivalent, shows that our dynamics reproduce the experiments with high precision. Furthermore, we simulate the (hitherto unmeasured) elastic ultrafast electron diffraction signal and show that it contains significant features directly related to the nuclear dynamics of the photoswitching event. Our atomistic simulations thus identify ultrafast electron diffraction as an excellent technique for studying the photoswitching of DHA/VHF derivatives and that this could aid in the design and development of new related compounds with optimized switching quantum yields.

Solar irradiation variability in the high Andean region of Amazonas-Peru: Spatiotemporal climatic perspective to evaluate the potential for solar energy implementation

Bias-free photoelectrochemical devices provide a sustainable route for solar hydrogen production from alkaline seawater, however, the requirement for large potential for anodic oxygen evolution and undesired chloride oxidation in seawater limit their efficiency. By leveraging the low oxidation potential of hydrazine, a toxic pollutant, bias-free devices can achieve high-performance hydrogen production and simultaneous degradation of hydrazine, effectively avoiding chloride oxidation. Here, we design a self-powered artificial leaf device, comprising a perovskite photocathode integrated with a noble-metal-free oxide catalyst for direct solar hydrogen production and hydrazine oxidation. The device exhibits a high photocurrent density of 25 mA cm-2 and stability for 3 days under 1-sun illumination. Upscaling the artificial leaf device enables near-complete hydrazine degradation to below 1 ppb within ≈ 30 h under zero-bias operation. This study provides a scalable and sustainable approach for simultaneous hydrogen generation and pollutant removal, advancing the use of solar energy in environmental applications.

In the context of the present day, the availability of non-renewable energy resources is declining, and the energy demand is on the rise with the increase in population and technological advancements. Although the use of solar energy and other forms of renewable energy has been integrated with the conventional energy grid, the intermittent nature of these forms of energy often creates an energy supply-demand imbalance and inefficient use of energy. To overcome the problems associated with the efficient use of energy, the present work proposes the development of an AI-based smart grid energy prediction system called NeuroWattic, which optimizes the use of energy, prevents wastage of energy, and promotes the efficient use of renewable energy. The model uses the stacking ensemble learning method, which combines the Random Forest, Extreme Gradient Boosting (XGBoost), and Histogram-based Gradient Boosting Machine (HistGBM) models as the base models, and the Ridge Regression model as the meta-model for efficient energy prediction. The model has been trained with high-resolution, multi-zone power consumption data, with a time resolution of 10 minutes, and meteorological data such as temperature, humidity, wind speed, and solar irradiance. Feature engineering has been done on the dataset, which creates temporal features, lag features, and weather-based features, which are used to model the complex energy consumption patterns. The model has been designed to perform iterative multi-step forecasting up to 14 days into the future, which enables efficient energy management. The performance of the model has been tested, and the results indicate significant improvement in the efficiency of the model, with an RMSE of 183.18 kW, MAE of 93.83 kW, MAPE of 0.1537%, and R² score of 0.9998. Moreover, the model has been integrated with an interactive dashboard that enables real-time monitoring, visualization of the duck curve, and cost optimization. The proposed system provides a scalable and intelligent solution for improving energy efficiency and enabling reliable renewable energy integration in modern smart grids.

Heterogeneous photocatalysis is one of the most versatile and widely studied photochemical approaches for the degradation of recalcitrant pollutants. Owing to its favorable physicochemical properties, titanium dioxide (TiO2) remains one of the most investigated semiconductor photocatalysts. However, its wide band-gap energy (3.2 eV) restricts its photoactivity to the UV region, which represents only a small fraction of the solar spectrum. A major challenge in this field is therefore the development of TiO2-based materials capable of operating efficiently under visible light irradiation, enabling the use of solar energy as a sustainable primary source. Several strategies have been explored to extend the optical response of TiO2, among which elemental doping remains one of the most effective and commonly applied. In this work, we conducted systematic comparative analysis to evaluate the photocatalytic performance of TiO2 modified through different doping approaches. Sixty-one scientific reports published between 2015 and 2025 were analyzed, comparing three categories of dopants: (i) metal dopants, (ii) non-metal dopants, and (iii) co-doping systems. In the first section, we discuss fundamental concepts of photocatalysis and recent advances in doping strategies and surface modifications aimed at enhancing the photocatalytic performance of TiO2. In the second section, we present a comparative analysis based on 61 scientific reports focusing on TiO2 doping and co-doping processes. Finally, this study summarizes the different categories of doped TiO2 photocatalysts by comparing the photocatalytic performance employing an alternative performance metric.

Adoption of various measures to reduce CO2 is showing positive results. Now increase in CO2 emission in fiscal year 2023 was lesser than increase in GDP. Use of solar, wind and electric energy is replacing fossil fuel-based systems. Thermal power plants and other waste to energy plants still generate considerable amount of carbon foot print. Channelizing this carbon, considering it to be a misplaced resource to produce biomass in an integrated system is a feasible option to be explored.

The construction sector is one of the largest contributors to global energy consumption and greenhouse gas emissions. High thermal losses and over-reliance on mechanical heating or cooling systems are due to the frequent failure of traditional facades to adapt to changing environmental conditions. Inspired by natural systems such as the thermic cooling of plant leaves and the responsive structure of pine trees, this study provides an algorithmic bio-inspired framework for adaptive building facade design. The framework optimizes the geometry of the facade and the material response to occupancy dynamics, temperature, and sunlight, combining evolutionary algorithms, swarm intelligence, and morphogenetic principles. Conventional methods, because of their rigid control logic, often fail to strike the right balance between performance, comfort, and aesthetics. To achieve a dynamic balance between energy consumption and indoor comfort, the proposed framework will introduce an adaptive, self-organising mechanism that continuously changes the elements of the facade in real time. Computational simulations using parametric modelling and energy-use analysis tools shall be performed to evaluate metrics like temperature comfort index (PMI), solar heat gain coefficient (SHGC), daylight autonomy (DA), and energy use intensity (EUI).

Optimizing solar energy use in large irrigation networks: The role of elevation differences in the Genil Margen Izquierda case study, Spain

The sustainable use of solar energy to drive multielectron catalytic processes is one feasible route toward the production of carbon-neutral compounds. In this study, we created a light-harvesting TTfCOF photocatalyst that resembles a chrysanthemum flower. Condensing 2,4,6-tris(4-aminophenyl)-1,3,5-triazine (T) with triformyl phloroglucinol (Tf) yields a robust two-dimensional covalent chemical framework. The remarkable photoredox activity of the modified COFs enables highly effective visible-light-driven NADH regeneration (65.27%), demonstrating that it can enable multielectron transfer with minimal energy loss. Beyond recycling cofactors, the chrysanthemum-flower-like TTfCOF platform efficiently uses solar energy to reduce CO2, generating 156.65 μmol of formic acid, demonstrating its potential for environmentally friendly solar-to-fuel conversion. Additionally, the chrysanthemum-flower-like TTfCOF photocatalyst and Fe3O4 nanoparticles combine to form a synergistic catalytic interface that significantly enhances the synthesis of pyrano-fused benzophenazines, producing remarkable outcomes (up to 76%). This integrated photocatalytic system shows how cofactor regeneration, CO2 valorization, and value-added synthesis may all be combined in a single solar-activated system. All things considered, our research produces a flexible 2D-COF design that can speed up the development of solar-powered chemical production platforms and enable sustainable catalytic cascades.

In the Nordic countries, seasonal variations limit the use of solar energy due to a mismatch between energy supply and demand. As the expansion of solar technology installation, especially photovoltaics (PV), evaluating multiple solar energy production systems in combination with storage systems, including both heat and electricity demand, is of particular interest for large industry and business parks. This study aims to assess the matching of solar energy supply with the local community’s power and heat demands of a business park consisting of warehouses. Various installation coverage of rooftop PV panels and solar Thermal (ST) systems, combined with thermal energy storage (TES) of different sizes, have been evaluated. The input data includes roof area, solar irradiation, PV power production from an existing system, electricity (annual amount 1.41 GWh), and heat (annual amount 6.58 GWh) demand profiles, as well as district heating distribution and ambient temperatures. Key technical parameters analyzed are the self-Consumption (SC) and self-Sufficiency (SS) ratios, evaluated for electricity, heat, as well as the overall energy system (i.e., the combined electricity and heat). Additionally, excess and imported electricity, energy balance, and waste heat are estimated. The results show that a significant portion of the produced heat is wasted, while surplus PV electricity can be exported to the grid, generating some economic value. The currently assumed TES capacity (70 MWh) is insufficient to store the total excess heat, leading to poor SC and SS ratios. Overall, the TES required to reach high self-sufficiency should be large in size, which in fact is infeasible, while smaller storage does not make a noticeable impact. Moreover, achieving a zero-waste heat and a complete heat SC scenario with a 70 MWh TES capacity would require allocating 7% installation coverage of the roof area to ST (equivalent to 1.2 MW). Concurrently, the PV system will cover 48% installation coverage of the roof area due to the power point of connection limit (equivalent to 1.4 MW). Therefore, leaving unutilized area could be an advantageous solution for the future, when TES or the power point of connection capacity is expanded or excess thermal energy is utilized. Future research could focus on a techno-economic assessment to determine the optimal system size by balancing economic and technical metrics, potentially including other energy storage or boiler technologies.

Growing environmental pressures and energy-related expenses in biomass supply chains (BSCs) call for operational strategies that simultaneously reduce emissions and total system costs. Despite extensive research on sustainable logistics, the environmental burden caused by transportation delays and queue-induced idling has been largely neglected. This study introduces the first bi-objective optimization model that integrates a G/M/S//M queuing system (QS) into BSC transportation operations while deploying solar panels (SPs) to power agricultural facilities with clean energy. The model explicitly minimizes both pollution and cost by reducing idle emissions during waiting times (WTs) and replacing grid-supplied electricity with renewable energy. Small-scale instances are solved using an exact analytical approach, while large-scale scenarios are optimized through the Grasshopper Optimization Algorithm (GOA). Sensitivity analyses confirm that increasing truck capacity without enlarging fleet size significantly decreases queue lengths, leading to lower emissions and reduced fuel-related costs. Furthermore, solar energy usage consistently outperforms grid electricity in economic performance, especially under higher-capacity SP installations. The proposed solution framework offers practical guidance for decision-makers seeking cleaner and more cost-efficient biomass logistics operations.

The heating transition, which involves shifting from a carbon-based energy supply to CO2-free and renewable energy sources, is both an economic and ecological necessity. Achieving this requires solutions that defossilize and largely decarbonize the heating sector in both the short and long term. At the technological level, we can reach this goal through innovative heating systems. However, in addition to technical possibilities, market conditions must be adapted to facilitate the transformation of the energy supply. Heat transformation plans, the Building Energy Act in Germany, development plans, building regulations, subsidies, customs regulations, state support for coal, gas, and oil supplies, and numerous other economic policy measures define the speed and direction of this change. Transparency about performance, situational feasibility, and the interplay of these individual elements create a mosaic of potential solutions. A methodical approach and fact-based discussions within the innovation system are essential for sustainable solutions. All relevant stakeholders must be involved—only by working together can we fully harness this opportunity for a stronger economic future. For 33 years, this symposium has made a significant contribution to this effort. The use of solar energy for heat generation is an extremely efficient and environmentally friendly way to meet our heating demands. When combined with existing fossil-fired heating systems, it can immediately reduce greenhouse gas emissions significantly. When paired with heat pumps, it ensures a high level of local supply security, provides relief to the grids even after the fossil fade-out, and enables effective sector coupling. Integrating solar thermal energy into heating networks, along with combining it with surplus electricity use and heat pumps for managing large thermal storage systems, offers complex but highly effective potential for CO2-free, grid-connected heat supply. In areas where space is limited, the combination of photovoltaics and solar thermal energy in hybrid PVT collectors can be an efficient space-saving solution. When heat pumps are also combined with PVT collectors, additional local benefits arise, providing a viable option for the widespread distribution of innovative heating solutions. Our symposium provides a unique opportunity to share advancements in solar thermal and renewable heating systems, learn from each other, and explore new avenues for the future. The diversity of experts, companies, and research institutions represented promises a broad range of perspectives and insights that will help us meet the challenges on the path to sustainable heating. Developing innovative heating systems is crucial for expanding the role of solar thermal energy. This involves not only the efficient conversion of solar energy into heat but also the integration of these systems into existing infrastructures through digitalization, as well as the creation of intelligent storage and control systems. We need solutions that make both ecological and economic sense and meet the demands of modern society. I am confident that this symposium will facilitate the exchange of ideas and the forging of new partnerships. It provides a platform to collaborate on solutions that will advance the energy transition and increase the market penetration of renewable heating systems. By leveraging new technologies, materials, concepts, and system intelligence, we can further enhance efficiency, reliability, and attractiveness.

Although Egypt falls within the solar belt, solar energy use on the household level remains very sparse. This research examines the factors driving and hindering households’ willingness to shift from fossil fuels to solar energy. The study evaluates the socioeconomic determinants of households’ willingness to adopt photovoltaic (PV) solar panels, based on a random distribution of 301 questionnaires in Cairo and Giza – two of Egypt’s most densely populated governorates. Two models were used? a Logistic Model and a Structural Equations Model (SEM) that regresses the willingness to install PV panels on household characteristics. For a deeper analysis of how socioeconomic differences shape renewable energy adoption, we separated the SEM model into behavioural and economic characteristics to be able to identify whether willingness to adopt solar PV systems, (or the lack of), stem from either set of factors. Accordingly, these insights can inform policy and support the implementation of targeted actions in both directions. Behavioural factors include household heads’ willingness to take a credit facility to finance solar PV panels, household heads’ level of education, living in rural versus urban areas, household size, whether any of the household members needed medical attention owing to heat waves during past year, household heads’ age and gender. Economic variables include household heads’ monthly income, whether the household owns a farm, whether the household owns gas at home, access to internet connection at home, access to credit facility, the number of times on average the household was disconnected from electricity per week during the past year, and education reflecting the socioeconomic level of the household head. Behavioural variables that positively contribute to adopting solar panels are revealed to be willingness to take a credit facility, age, education and household members needing medical attention owing to heat waves during past year; behavioural variables that contribute negatively to solar panel adoption include gender of the household head (in favour of females) and the geographical dimension (in favour of rural areas). The economic model’s results reveal a positive relationship for the average monthly income of the household head, ownership of farmland, and the years of education of the household head. Households with access to internet at home is negatively associated with the willingness to install solar panels. Suggested policy implications include packages that target programs supporting low-income households. Keywords: PV Solar Panels, Behavioural & Socioeconomic determinants, Structural Equation Model, Logistic Regression Model

The present study “Attitude of farmers towards solar energy utilization in farming system “ was conducted in Amravati district of Nandgaon khandeshwar, and Amravati tahsil were selected randomly. The Ex-post-facto research design was used in the present investigation. The present study was carried out in the Amravati district of the Vidarbha region to know the attitude of the farmers towards solar energy use in agriculture. There are 120 solar pump using farmers selected from two tahsil. All farmers were selected purposively for study. The data was collected by personally interviewing the respondents with the help of the presented structured schedule. The collected data was first tabulated, and then mean, frequency, standard deviation, and correlation were employed for interpretation of the findings. The characteristics of the farmers, namely age, education, land holding, family size, annual income, irrigation status, extension contact, economic motivation, risk orientation, scientific orientation, knowledge, were studied as independent variables. The attitude of farmers was studied as the dependent variable. Also the constraint faced by the farmers was studied in study area.

The use of solar energy for hydrogen (H2) production via water splitting is rapidly emerging as a promising clean energy source. Progress in this field depends on developing high-performance, stable catalysts that efficiently drive the hydrogen evolution reaction (HER). In this study, a simple hydrothermal method is employed to synthesize a medium-entropy quinary sulfide photocatalyst (Cd1-x-yNixMoyZn0.45S) capable of generating H2 directly from water without the use of additional cocatalysts. The quinary photocatalyst retains a distinct hexagonal lattice despite the partial substitution of Cd with earth-abundant elements Ni, Mo, and Zn, significantly reducing the Cd content without disrupting the crystalline phase. The optimal composition, Cd0.39Ni0.09Mo0.07Zn0.45S (CNMZS-3), exhibits a 6-fold enhancement in the H2 evolution rate of 2437.87 μmol g-1 h-1 compared to pristine CdS (419.75 μmol g-1 h-1), aided by engineered sulfur vacancies. CNMZS-3 also demonstrates excellent stability, maintaining its structural integrity and catalytic performance for 72 h with minimal degradation. Density functional theory (DFT) analyses reveal that the Mo sites serve as the most active centers for H adsorption, while Ni improves photoabsorption, creating a synergistic effect that boosts HER activity. Replacing the conventional oxygen evolution reaction (OER) with ethylene glycol (EG) oxidation further increases H2 production to 3746.74 μmol g-1 h-1 over 4 h, accompanied by the formate formation. Remarkably, CNMZS-3 also performs effectively in artificial seawater, achieving H2 evolution rate of 1786.79 μmol g-1 h-1. These findings highlight medium-entropy quinary sulfides as versatile bifunctional photocatalysts for H2 production from both freshwater and seawater, as well as for value-added chemical generation from EG.

The sustainable use of solar energy for dye degradation and organic transformations has gained significant attention. In this work, two-dimensional Pd-decorated Ti-based amine-functionalized metal-organic frameworks (Pd/NH2-MIL-125 (Ti)) were synthesized via in situ Pd nanoparticle deposition. The heterojunctions were fully characterized by various techniques (XRD, BET, FE-SEM, TEM, FT-IR, XPS, AFM, Raman, and X-ray mapping). The optimized catalyst (4.46 wt % Pd) showed a large surface area (849.61 m2/g) and remarkable photocatalytic efficiency under visible light. It achieved 94% conversion in Suzuki cross-coupling and high degradation efficiencies for Rhodamine B (RhB, 98.10 ± 0.780%) and Congo red (CR, 94.8 ± 0.720%) within 60 min, without H2O2 or additional photosensitizers. The enhanced activity is attributed to the synergistic interaction of Pd and NH2-MIL-125 (Ti), enabling efficient charge separation, narrowed band gap, and abundant active sites. Mechanistic studies identified superoxide radicals (·O2-) as key species in dye degradation. The catalyst also exhibited excellent recyclability, maintaining performance over five cycles.

This study investigates public awareness and social acceptance of solar energy as a strategy for reducing energy poverty in Tanzania, focusing on households, micro, small and medium enterprises (MSMEs), and health and education facilities. Guided by a positivist philosophy and a deductive approach, a cross-sectional survey was administered to 384 respondents. Data were analysed using descriptive statistics, cross-tabulations, Pearson correlations, multiple regression, and moderation analysis. The findings show that general awareness of solar energy is relatively high, yet practical knowledge on maintenance and financing remains limited. Awareness and acceptance vary significantly by stakeholder group, with higher levels among institutional users and MSMEs than households. Mass media is the dominant information source but exhibits the lowest conversion from awareness to adoption, while community engagement, peer referrals, and formal training achieve higher conversion rates. Regression results indicate that social acceptance, service availability, and financing options are the strongest predictors of sustained solar energy use, jointly explaining 64% of the variance. Moderation analysis reveals that reliable after-sales services and flexible financing significantly strengthen the link between awareness and sustained use, while gender-inclusive decision-making enhances acceptance and continuity at the household level. Longitudinal perceptions among adopters indicate improving attitudes over time when systems perform reliably and maintenance support is accessible. The study concludes that solar energy can meaningfully reduce energy poverty in Tanzania when deployed through people-centred, service-enabled, and gender-responsive approaches. Policy implications emphasise practical energy literacy, community-based outreach, strengthened service ecosystems, inclusive financing mechanisms, and monitoring frameworks that prioritise sustained use over installations.

Vietnam has increasingly acknowledged the critical role of sustainable energy in its long-term development strategy, particularly in response to the projected depletion of fossil fuel reserves and the escalating effects of climate change. Among the sustainable energy sources that need to be exploited, solar energy is emerging as a renewable energy source that plays a key role in Vietnam's sustainable development strategy. With its advantages of natural conditions, high radiation intensity, and long sunshine hours, Vietnam has great potential for exploiting and applying solar energy. Adopting and implementing a strategic orientation for sustainable energy development by 2030 and a vision for 2045 is another way the Vietnamese government has demonstrated its dedication to priorities. These initiatives promote the supply of reliable, superior, and affordable energy sources for long-term socioeconomic growth, contributing to environmental preservation. However, the development and exploitation of solar energy still face many challenges, including limitations in transmission infrastructure, unstable policy mechanisms, high initial investment costs, and issues related to the storage and management of renewable energy sources. This study focuses on analysing the mission of solar energy in contributing to ensuring energy security, reducing greenhouse gas emissions and promoting green growth in Vietnam; at the same time, pointing out the main challenges, potential for solar energy development and proposing practical solutions to effectively exploit the available potential. With the right guidance and sustained policy support, solar energy has the potential to play a significant role in Vietnam's energy transition and long-term environmentally friendly economic growth.

Vietnam has increasingly acknowledged the critical role of sustainable energy in its long-term development strategy, particularly in response to the projected depletion of fossil fuel reserves and the escalating effects of climate change. Among the sustainable energy sources that need to be exploited, solar energy is emerging as a renewable energy source that plays a key role in Vietnam's sustainable development strategy. With its advantages of natural conditions, high radiation intensity, and long sunshine hours, Vietnam has great potential for exploiting and applying solar energy. Adopting and implementing a strategic orientation for sustainable energy development by 2030 and a vision for 2045 is another way the Vietnamese government has demonstrated its dedication to priorities. These initiatives promote the supply of reliable, superior, and affordable energy sources for long-term socioeconomic growth, contributing to environmental preservation. However, the development and exploitation of solar energy still face many challenges, including limitations in transmission infrastructure, unstable policy mechanisms, high initial investment costs, and issues related to the storage and management of renewable energy sources. This study focuses on analysing the mission of solar energy in contributing to ensuring energy security, reducing greenhouse gas emissions and promoting green growth in Vietnam; at the same time, pointing out the main challenges, potential for solar energy development and proposing practical solutions to effectively exploit the available potential. With the right guidance and sustained policy support, solar energy has the potential to play a significant role in Vietnam's energy transition and long-term environmentally friendly economic growth.

Considering the aspiration to achieve sustainability in various fields, including energy, this study aims to identify the optimal angles for solar panel tilt in Iraq, specifically in three cities: Baghdad, Basra, and Mosul, with the aim of promoting the use of solar energy as a clean, renewable energy source. In light of the global energy crisis, a quantitative analytical methodology was used, utilizing historical solar radiation data spanning 18 years (2006-2024) to determine the optimal angles for receiving the best amount of solar radiation. The results showed that the optimal angles ranged between 28° in Basra, 31° in Baghdad, and 33° in Mosul. The results also indicated that various climatic influences, such as high temperatures, dust, and wind speed, affected the performance of solar panels, especially in the summer and winter. Therefore, the study recommends the use of a monthly angle adjustment system to achieve solar radiation utilization using Mono-Si solar panels, given their high efficiency under the prevailing climatic conditions.