Shading Factor Research Articles

Design and Simulation of a Solar Powered House in Muğla: Roof Decorated with Half Cut Cells

In this article, the performance, design and efficiency calculation of photovoltaic systems were made using PvSol program. For roof type panel design close to standard installations, panel position and panel type were designed based on Muğla province sun hour data and roof shading factor. In this study, the data obtained for the roof type installation designed in Muğla city using monocrystalline, polycrystalline and half-cut monocrystalline cells were compared. When yield, area and price parameters were compared, it was found that the best cell type was half-section monocrystalline. As a result of the simulations, it was found that the average daily energy need of the house is 6.4kWh, fed by 14 half-section monocrystalline panels. The results obtained are consistent with the data in the literature.

Apple (Malus × domestica Borkh.) production and quality in response to anti-hail nets.

Anti-hail nets are the best way to mitigate the effects of hailstorms in the orchards. Apple trees covered with nets may exhibit a variety of vegetative and reproductive responses, inclusive of changes in tree vigour, cropping, sugar contents, and fruit colour. The present study was conducted to assess the effect of timing of installation and colour of anti-hail net on cropping and fruit quality in high-density apple orchard for two consecutive seasons (2021 and 2022). White and blue colour nets of size (9m × 30m) 80 GSM (square mesh with non-sliding threaded, leno weave, and < 30% shading factor) were installed at three different time intervals (15days before estimated full bloom, at full bloom, and 15days after full bloom) on apple cultivar 'Jeromine'. The installation at different time and colour of anti-hail nets significantly exhibit variability in cropping, fruit quality, and bio-chemical metrics. The significant highest cropping (fruit yield, productivity, and yield efficiency) and fruit biochemical parameters (total soluble solids) were recorded in T3C2 (15days after full bloom + white colour anti-hail net) followed by T2C2 (installed at full bloom + white colour anti-hail net). Hence, white colour anti-hail nets installed 15days after full bloom increased fruit production and improved quality in comparison to blue colour anti-hail net in apple under high-density plantations.

A Method to Compute Shadow Geometry in Open Building Information Modeling Authoring Tools: Automation of Solar Regulation Checking

Building solar protection regulations is essential to save energy in hot climates. The protection performance is assessed using a shading factor computation that models the sky irradiance and the geometry of shadow obstructing the surface of interest. While Building Information Modeling is nowadays a standard approach for practitioners, computing shadow geometry in BIM authoring tools is natively impossible. Methods to compute shadow geometry exist but are out of reach for the usual BIM authoring tool user because of algorithm complexity and non-friendly BIM implementation platform. This study presents a novel approach, dubbed solid clipping, to calculate shadow geometry accurately in a BIM authoring tool. The aim is to enhance project delivery by enabling solar control verification. This method is based on typical Computer Aided Design (CAD) in BIM authoring tools. The method is generic enough to be implemented using any BIM authoring tool’s visual and textual API. This work demonstrates that a thermal regulation, here the French overseas one, can be checked concerning solar protection, thanks to a BIM model. Beyond automation, this paper shows that, by directly leveraging the BIM model, designs presently not feasible by the usual process can be studied and checked.

Study on the Influence of the Energy Intensity of Residential District Layout on Neighborhood Buildings

Numerous prior studies have substantiated the influence of residential layout on building energy consumption; however, their principal emphasis has predominantly been on urban and neighborhood contexts. Nevertheless, research conducted at the cluster scale has the potential to augment the well-being of neighboring communities and render the objective of a reduction in energy consumption more pertinent to residents’ daily lives. Furthermore, there is a shortage of more robust metrics capable of quantifying the degree of mutual shading among individual buildings within residential neighborhoods. This shading factor constitutes a pivotal element impacting the energy consumption of individual structures. This study utilizes the VirVil-HTB2 tool to calculate solar radiation intensity for individual buildings, serving as a shading metric. Correlation and linear regression analyses are employed to quantify the causal relationship, allowing us to investigate the impact of residential complex layouts on the energy efficiency of individual buildings. The findings of this study indicate that solar radiation serves as a precise metric for gauging shading intensity among buildings, and building energy consumption exhibits a distinct block-like distribution pattern within the residential complex. Furthermore, through an analysis of the level of inter-building shading and a judicious optimization of the layout, it is feasible to achieve a reduction of up to 4.03% in heating energy consumption and a maximum reduction of 4.39% in cooling energy consumption.

Impact Analysis of Metallization Design and Recombination Losses on Performance of Crystalline Silicon Solar Cells

Using Griddler software, this study aims to select the optimal metallization design by analyzing the impact of the number and sizes of busbars and fingers on a solar cell’s performance. There is interest in the PV industry to reduce the finger size toward 25 μm in upcoming years. It is shown that an increase in the number and size of busbars and fingers causes an increase in the fill factor; however, with regards to the cell’s efficiency, the shading factor should be considered in addition to the size and number of metal contacts. The results of this study indicate that solar cells’ efficiency could be increased by 0.33–0.84% when using five busbars and a finger width of 35 μm. Moreover, this increase is achieved by reducing the emitter resistance to less than 60 ohm/sq and considering a recombination rate of about 165 fA/cm2.

Rare shady chasmophytic habitat communities (8210) in Ukraine

Abstract The characteristics of shaded chasmophytic habitats on calcareous rocks in forest conditions are described, where the forest canopy primarily acts as a shading factor that determines microclimate, humidity and light levels. These communities can be found in deciduous forests of the Carpinion betuli, Fagion sylvaticae and Tilio-Acerion alliances, where they are confined to steep calcareous rock faces and cliffs. Syntaxonomically, these communities belong to the Polypodietea class (Ctenidio-Polypodietalia vulgaris order, Ctenidio-Polypodion vulgaris alliance) and to four informal communities: Isothecium alopecuroides-Polystichum braunii, Porella platyphylla-Asplenium ruta-muraria, Pseudanomodon attenuatus-Chrysosplenium alternifolium and Pedinophyllum interruptum-Polystichum aculeatum. We evaluated indices of environmental parameters according to the synphytoindication method using Didukh’s scales. An assessment of the threat impacts and indicators of sociological significance shows that the habitat belongs to a rare type (II class), and therefore requires specific conservation measures.

Shading Calculation Methods and Regulation Simplifications—The Portuguese Case

How to analyse the omissions of thermal regulations and evaluate methodologies that provide building execution or thermal certificates that do not correspond to reality and usually incur costs? We can start by analysing different simulation methods and shading calculations that provide solar gains and shadow optimisation. After evaluating how the regulations define the calculation assumptions and how this calculation is performed, the discrepancies (simplifications) that the regulations allow or ignore are presented, and it is exemplified using two case studies. Using the Portuguese regulation as a case study, it leads to incorrect conclusions or assumptions due to unequal access to solar radiation or the shading factor calculation that experiences the omission of angles or time periods. Therefore, the aim is to propose a calculation process (premises) that minimises the discrepancies between simulation (optimisation strategy) and reality (applicability of strategies) for sustainable output.

A new trigonometric model for solar radiation and shading factor: Varying profiles of building façades and urban eccentricities

Solar energy utilizations in buildings are contingent on efficient shading models. This paper presents a new trigonometric model that was simple in application and robust in handling diverse site environments. The developed model was experimentally validated and compared to existing shading techniques such as pixel counting and polygon clipping. Additional analyses were performed to examine building façades ranging from flat to free-form surfaces in both linear and non-linear urban forms. This study integrated two submodels into the shading model to estimate the reduction in cooling demand and the energy production from solar applications. On annual basis, elliptical urban grids provided less normal beam radiation by a mean of 4.7 % or 22.8 W/m2 than the linear grids tangent to the curvilinear ones. South-facing façades gained more radiation by a factor ranging from 1.26 to 1.55 due to wider street grid conditions. Shade-less protrusions of the free-form façades allowed the incidence factor to reach up to 0.91 compared to 0.35 in flat façades. Although the developed model had an average error of 5.2 %, the computational time was reduced by more than 40 %.

PARAMETRIC ESTIMATION OF ELECTRICAL ENERGY GENERATION FROM ROOF-MOUNTED PHOTOVOLTAICS FOR CLUSTERED SETTLEMENTS: A CASE STUDY OF A PROPOSED SPECIAL ECONOMIC CITY

Abstract: This paper presents a parametric model specifically designed to estimate the solar energy potential from roof-mounted photovoltaic (PV) systems in a proposed Special Economic City. The study focuses on phase one of the city, which includes various building types such as an international conference centre, hotels, schools, residential buildings, and hospitals. The parametric model is developed based on a thorough theoretical framework and an extensive literature review. Literature indicates that the proposed city's geographical context offers an average solar irradiation of 3.4 kWh/m2day. By adopting an optimal tilt angle of 10º relative to the horizontal, aligned with the city's latitude, and a generally southerly orientation of PV panels, the energy yield can be further optimized. A conservative 22% shading factor is adopted in the absence of site-specific shading data. To ensure practicality and space utilisation, the model accounts for only 60% of the total roof area to be utilized for PV installation, leaving space for circulation during maintenance works. The developed parametric model serves as a valuable tool for designing and optimising PV systems within the city's clustered settlements, contributing to a sustainable and energy-efficient urban environment. The findings offer essential insights for informed decision-making and future investments in solar energy infrastructure, positioning the city as a lead hub for renewable energy utilisation and driving economic growth in Northern Nigeria. Embracing solar energy presents a promising opportunity for the city to establish itself as a sustainable and thriving centre for business and living.

Research and Exploration of Green Building Based on the Basic Theory of Urban Development

Firstly, the influence of building design factors on building carbon emissions was analysed, and the influence of building form factor, building orientation and building envelope on building carbon emissions was simulated and studied, which shows that the south-facing direction has the lowest building carbon emissions, the external window shading factor is negatively related to building carbon emissions, and all other factors are positively related to building carbon emissions. The existing low carbon evaluation systems were then analysed, most of which suffer from a lack of carbon emission calculation methods and a lack of comprehensive scoring methods. This paper establishes an evaluation index system based on the principles of evaluation system construction, determines the benchmarks for index evaluation based on energy saving standards and research data, delineates the range of evaluation index parameters and the percentage of scores, and establishes an evaluation index system. The weights of the evaluation indicators were calculated using hierarchical analysis and combined with expert questionnaires, and a comprehensive scoring method was established based on the weights to build a building carbon emission evaluation system.

An Experimental Study on Performance Evaluation of Shading Matrix to Select Optimal Parking Space for Solar-Powered Electric Vehicles

This study evaluated the applicability of a shading matrix generated using hemispherical fisheye images to select the optimal parking space to maximize the photovoltaic (PV) power generation of solar electric vehicles. The study aims to identify the maximum power point (MPP) of a PV module in a parking space using current–voltage measuring equipment to determine whether the shading matrix reflects any shadow phenomenon. The experiment was conducted on a parking lot at Daeyeon Campus. The fisheye images were taken in seven parking spaces. The shading matrices were generated by tracking the position of the sun over 12 months and 24 h periods. A 50 W PV module was installed on the roof of the vehicle and the MPP was measured in five experiments (9 a.m., 11 a.m., 13 p.m., 15 p.m., and 17 p.m.) in seven parking spaces. In parking spaces with a shading factor of 0, the PV modules were not shaded at all during the experiment, and the average MPPs were 34, 43, 37, and 21 W at 9 a.m., 11 a.m., 13 p.m., and 15 p.m., respectively. The shading matrix calculated using the fisheye images accurately reflected the shadow phenomenon that decreases PV power generation.

Smart Dimmable LED Lighting Systems.

This paper proposes energy-efficient solutions for the smart light-emitting diode (LED) lighting system, which provides minimal energy consumption while simultaneously satisfying illuminance requirements of the users in a typical office space. In addition to artificial light from dimmable LED lamps, natural daylight coming from external sources, such as windows, is considered as a source of illumination in an indoor environment. In order to reduce total energy consumption, the smart LED system has the possibility to dim LED lamps, resulting in reduced LED output power. Additionally, various LED lamps' functionality, such as semi-angle of the half illuminance and LED tilting, are introduced as an additional parameter to be optimized to achieve greater energy saving of the designed system. In order to properly exploit external lighting, the idea to reduce overall daylight intensity at a users' location is realized by the option to dim the windows with a shading factor. Based on the users' requirements for a minimal and desired level of illumination, the proposed optimization problems can be solved by implementing different optimization algorithms. The obtained solutions are able to give instructions to a smart LED system to manage and control system parameters (LEDs dimming levels, semi-angles of the half illuminance, orientation of LEDs, the shading factor) in order to design total illumination, which ensures minimal energy consumption and users' satisfaction related to illuminance requirements.

Improvements in methods for analysis of partially shaded PV modules

Several methods for analyzing photovoltaic (PV) systems under partial shading conditions (PSC) can be found in the literature. However, the simplest methods are not very accurate. This article presents (1) a simple and accurate method to model I–V curves for PSC and (2) an improvement of a simplified method, without calculating the I–V curves, to accurately estimate the energy generated by PV systems under PSC. The I–V curves of two PV modules under PSC were measured. The measured curves were compared with modeled curves using two methods from the literature and a new proposed method. Four simplified methods from the literature for estimating the energy generated by PV systems were analyzed. The accuracy of these methods was investigated by comparing the calculated values with measured data from a PV system. For modeling the I–V curves, the new method showed a mean absolute percentage error of 1.5% and proved to be accurate. For the evaluated PV system, using a monthly database and the proposed diffuse shading factor resulted in differences between the measured and modeled results of up to 10% per month and 5% for the entire measurement period. The two proposed methods are simple and accurate.

Impact of invasive species Parectopa robiniella (Gracillariidae) on fluorescence parameters of Robinia pseudoacacia in the conditions of the steppe zone of Ukraine

Robinia pseudoacacia L. is one of the most common and environmentally adaptable introduced tree species which has become an important element of artificial afforestation and landscaping in Ukraine over the past 150 years. Throughout the history of its introduction on the territory of Ukraine, this species was considered resistant because of the absence of dangerous phytophages. At the beginning of the XXI century, the phytosanitary situation changed as the result of the penetration and rapid spread of a number of North American invasive phytophages. The appearance and distribution of the miner Parectopa robiniella (Clemens, 1863) (Lepidoptera, Gracillariidae) feeding on R. pseudoacacia was recognized as the largest invasion in Ukraine. This paper considers the issues of studying the effect of P. robiniella caterpillars feeding on R. pseudoacacia in various forest-growing conditions in the steppe zone of Ukraine. The process of photosynthesis, as the most important physiological parameter, was chosen as indicator of condition. The study was conducted using biosensor technology which made it possible to measure the effect of caterpillar feeding on critical parameters of chlorophyll fluorescence (the Kautsky curve). The research has shown that the initial value of fluorescence induction was within the range of 196–284 RFU, and the maximum value of the background fluorescence parameter was recorded in undamaged leaves and under shading conditions. Both the effect of phytophages and the shading factor caused a significant decrease in the values of fluorescence induction of the “plateau” both in the conditions of an artificially washed sandbar, on the watershed area of a watershed-gully landscape, as well as on natural sandy-loam soil. The maximum values of photosynthetic fluorescence induction under the simultaneous influence of the studied factors had rather high variability. In contrast to the fluorescence induction parameter, the “plateau” of the highest maximum fluorescence induction was reached in the absence of pest damage under conditions of total shading. As revealed by dispersion and regression analyses, the maximum fluorescence index was most dependent on the amount of solar radiation and on the degree of the leaf surface damage by phytophages. Significantly higher values of the steady-state fluorescence induction parameter were determined in the absence of insect damage in both shading and lighting conditions. A statistically significant combined influence of abiotic and biotic factors on the “plateau” fluorescence induction parameter was determined in comparison with the mono-influence of individual factors. A highly significant dependence of the maximum efficiency indicator of primary photosynthesis processes on individual factors of exogenous influence was established, while the combined effect of these factors did not affect this parameter. The obtained data allow one to apply in practice the methods of analyzing chlorophyll fluorescence induction to establish the physiological state of tree flora in forest and garden farms.

Benefitting from Solar Energy Due to Different Emissivity Levels of Multiple Glass Windows for Buildings

In the study, firstly, heat transfer coefficients of windows were calculated according to the highest and lowest emissivity values. Secondly, monthly average solar radiation values were determined. The heat transfer coefficient calculated for double, triple and quadruple glass windows. Thirdly, the solar radiation in the south, north and east/west directions of the five climatic zones were multiplied by the shading factor, surface area and the solar energy factor of discrete buildings. Thus, the solar energy gain value for the heating period and solar energy losses for cooling period was determined. Finally, passive solar energy gains are calculated during the heating and cooling period for all climate zones. It has been calculated that in the fifth climatic zone in south direction, heat loss from windows with 0.05 emissivity can be provided with passive solar energy by 167.9% in double-glazed windows, 258.7% in triple-glazed windows and 349.1% in quadruple-glazed windows.

Understanding the Reasons behind the Energy Performance Gap of an Energy-Efficient Building, through a Probabilistic Approach and On-Site Measurements

The performance gap, defined as the difference between the measured and the calculated performance of energy-efficient buildings, has long been identified as a major issue in the building domain. The present study aims to better understand the performance gap in high-energy performance buildings in Switzerland, in an ex-post evaluation. For an energy-efficient building, the measured heating demand, collected through a four-year measurement campaign was compared to the calculated one and the results showed that the latter underestimates the real heating demand by a factor of two. As a way to reduce the performance gap, a probabilistic framework was proposed so that the different uncertainties of the model could be considered. By comparing the mean of the probabilistic heating demand to the measured one, it was shown that the performance gap was between 20–30% for the examined period. Through a sensitivity analysis, the active air flow and the shading factor were identified as the most influential parameters on the uncertainty of the heating demand, meaning that their wrong adjustment, in reality, or in the simulations, would increase the performance gap.

A new methodology for the assessing of power losses in partially shaded SPV arrays

This paper describes a novel methodology for estimating the shading factor and the irradiance in partially shaded photovoltaic arrays. The results indicate that the monitoring of short circuit currents obtained from the IV curves of shaded and unshaded modules can be used to calculate the overall irradiance on partially shaded and not shaded photovoltaic arrays. This new methodology avoids the need to use several irradiance sensors to map the shaded and unshaded regions. Besides that, this paper presents a simple mathematical model to estimate shading losses on SPV arrays at the points of maximum global and local power. The methodology can be described in five steps: the measurement of the IV curve and cell temperature, pre-processing of the IV curve, calculation of the shading factor and irradiance on the shaded and unshaded areas, use of the photovoltaic array model to obtain the simulated IV curve and the shading level distribution in the array. The proposed model was developed using the methodology presented in this work, demonstrating how useful it can be to validate and develop models applied to evaluate the shading effects. Calculated losses are compared to those obtained with models found in the literature. The proposed model is useful for calculating the instantaneous power losses, requiring less information as input than other detailed models, and requiring low computational effort.

Shading Effect of a South Building on The Solar Collector Aperture.(Dept.M)

In the present work, the shading effect of a south building on the aperture of a solar device in the north latitudes is theoretically investigated. A mathematical model to calculate the instantaneous value of shaded area as a function of building horizontal distance, neight, width and the angle of deviation from south direction as well as aperture dimensions has been obtained. The shading factor, which is the ratio between the actual total incident solar radiation and that without shading on the aperture, has been calculated for different geometrical parameters. The annual average shading factor, which may be considered as a reasonable measure of the shading effect is also given in terms of the system dimensionless parameters.

Design and Analysis Performance Solar Power Plant 15 kW By Maximizing Final Yield and Performance Ratio In Small-Medium Office

The 15 kW solar power plant (PLTS) is a new certain in the application of small-medium solar energy usage, especially for the campus environment in Indonesia which can support and become proof of realization green campus program. The existence of 15 kW PLTS become an attention to do advanced analysis in order that production of the specific electric energy or final yield (YF) and performance ratio (PR) from a PLTS can be monitored based on installation location. The value of YF and PR can be used as reference to do identification, trouble operation analysis, and developing of a PLTS. The optimum value of YF and PR on the 15 kW PLTS resulted by doing simulation from a simulator software, which the value resulted from location and configuration of the system installation without watch shading factor. And then the simulation value compared with electric energy real production result on this 15 kW PLTS. The 15 kW PLTS divided be two lines, that are 5 kW and 10 kW line. From simulation result, showed that in the 5 kW line have value of optimum production is 5264.8 kWh with PR 83,1% and in the 10 kW line have value of optimum production is 7687.2 kWh with PR 83.12%. Real production in line 5 kW is 1326.9 kWh with difference 74.79% with simulation and in line 10 kW is 1643.3 kWh with difference 78.62% with simulation. The shading and existing disturbances resulted in a decrease in electrical energy production and performance in the line 5 kW is YF 0.91 hours/day with CF 2.79% and in the line 10 kW is YF 3.07 hours/day with CF 11.73%.

SWMM-UrbanEVA: A Model for the Evapotranspiration of Urban Vegetation

Urban hydrology has so far lacked a suitable model for a precise long-term determination of evapotranspiration (ET) addressing shading and vegetation-specific dynamics. The proposed model “SWMM-UrbanEVA” is fully integrated into US EPA’s Stormwater Management Model (SWMM) and consists of two submodules. Submodule 1, “Shading”, considers the reduction in potential ET due to shading effects. Local variabilities of shading impacts can be addressed for both pervious and impervious catchments. Submodule 2, “Evapotranspiration”, allows the spatio-temporal differentiated ET simulation of vegetation and maps dependencies on vegetation, soil, and moisture conditions which are necessary for realistically modeling vegetation’s water balance. The model is tested for parameter sensitivities, validity, and plausibility of model behaviour and shows good model performance for both submodules. Depending on location and vegetation, remarkable improvements in total volume errors Vol (from Vol = 0.59 to −0.04% for coniferous) and modeling long-term dynamics, measured by the Nash–Sutcliffe model efficiency (NSE) (from NSE = 0.47 to 0.87 for coniferous) can be observed. The most sensitive model inputs to total ET are the shading factor KS and the crop factor KC. Both must be derived very carefully to minimize volume errors. Another focus must be set on the soil parameters since they define the soil volume available for ET. Process-oriented differentiation between ET fluxes interception evaporation, transpiration, and soil evaporation, using the leaf area index, behaves realistically but shows a lack in volume errors. Further investigations on process dynamics, validation, and parametrization are recommended.