THE RELATIONSHIP BETWEEN DIFFUSE AND TOTAL SOLAR RADIATION IN COMPUTER SIMULATION OF SOLAR ENERGY SYSTEMS

Author(s):  
Federico Butera ◽  
Giuseppe Panno ◽  
Giovanni Ruisi
2019 ◽  
Vol 91 ◽  
pp. 05006
Author(s):  
Rami Qaoud ◽  
Alkama Djamal

The urban fabric of the desert cities is based on the principle of reducing the impact of urban canyons on direct solar radiation. Here comes this research, which is based on a comparative study of the periods of direct solarisation and values of the solar energy of urban canyons via two urban fabrics that have different building densities, where the ratio between L/W is different. In order to obtain the real values of the solar energy (thermal, lighting), the test field was examined every two hours, each three consecutive days. The measurement stations are positioned by the three types of the relationship between L/W, (L≥2w, L=w, L≤0.5w). According to the results, we noticed and recorded the difference in the periods of direct solarization between the types of urban engineering canyons, reaching 6 hours a day, the difference in thermal values of air, reaching 4 °C, and the difference in periods of direct natural lighting, reaching 6 hours. It should be noted that the role of the relationship between L/W is to protect the urban canyons by reducing the impact of direct solar radiation on urban canyons, providing longer hours of shading, and reducing solar energy levels (thermal, lighting) at the urban canyons. This research is classified under the research axis (the studies of external spaces in the urban environment according to the bioclimatic approach and geographic approach). But this research aims to focus on the tracking and studying the distribution of the solar radiation - thermal radiation and lighting radiation - in different types of street canyons by comparing the study of the direct solarization periods of each type and the quantity of solar energy collected during the solarization periods.


2019 ◽  
Vol 44 (2) ◽  
pp. 168-188
Author(s):  
Shaban G Gouda ◽  
Zakia Hussein ◽  
Shuai Luo ◽  
Qiaoxia Yuan

Utilizing solar energy requires accurate information about global solar radiation (GSR), which is critical for designers and manufacturers of solar energy systems and equipment. This study aims to examine the literature gaps by evaluating recent predictive models and categorizing them into various groups depending on the input parameters, and comprehensively collect the methods for classifying China into solar zones. The selected groups of models include those that use sunshine duration, temperature, dew-point temperature, precipitation, fog, cloud cover, day of the year, and different meteorological parameters (complex models). 220 empirical models are analyzed for estimating the GSR on a horizontal surface in China. Additionally, the most accurate models from the literature are summarized for 115 locations in China and are distributed into the above categories with the corresponding solar zone; the ideal models from each category and each solar zone are identified. Comments on two important temperature-based models that are presented in this work can help the researchers and readers to be unconfused when reading the literature of these models and cite them in a correct method in future studies. Machine learning techniques exhibit performance GSR estimation better than empirical models; however, the computational cost and complexity should be considered at choosing and applying these techniques. The models and model categories in this study, according to the key input parameters at the corresponding location and solar zone, are helpful to researchers as well as to designers and engineers of solar energy systems and equipment.


2016 ◽  
Vol 13 (4) ◽  
pp. 376-380 ◽  
Author(s):  
Abdelouahab Zaatri ◽  
Norelhouda Azzizi

Purpose Using modeling approaches, this paper aims to propose different mathematical models for estimating the different components of the solar radiation as well as the received solar energy by a collector. Design/methodology/approach In this article, the authors consider three mathematical models to estimate the solar radiation captured at ground level by a solar collector. These models are Capderou model, Liu & Jordan model and R.sun model. In the context of the design of experiments, we performed measurements of solar radiation received by a collector using a pyranometer. The obtained measurements were compared with the three mathematical models. Findings The comparison enabled the subsequent evaluation to determine the most appropriate model that best fit for our region. As a result, the Capderou model reveals to be the most suitable for our region. Originality/value Estimation of solar radiation at ground level (received by a collector) is of paramount importance for the design and optimization of solar energy systems. Nevertheless, many factors influence the amount of energy received by a collector situated at a ground, such as the longitude of the location, latitude, altitude, tilt collector orientation, temperature and humidity of the environment, wind speed, etc. Because of the complex influence of these parameters, the received solar radiation by the collector is a dynamical and a random process.


Author(s):  
Radian Belu

Artificial intelligence (AI) techniques play an important role in modeling, analysis, and prediction of the performance and control of renewable energy. The algorithms employed to model, control, or to predict performances of the energy systems are complicated involving differential equations, large computer power, and time requirements. Instead of complex rules and mathematical routines, AI techniques are able to learn the key information patterns within a multidimensional information domain. Design, control, and operation of solar energy systems require long-term series of meteorological data such as solar radiation, temperature, or wind data. Such long-term measurements are often non-existent for most of the interest locations or, wherever they are available, they suffer of a number of shortcomings (e.g. poor quality of data, insufficient long series, etc.). To overcome these problems AI techniques appear to be one of the strongest candidates. The chapter provides an overview of commonly used AI methodologies in solar energy, with a special emphasis on neural networks, fuzzy logic, and genetic algorithms. Selected AI applications to solar energy are outlined in this chapter. In particular, methods using the AI approach for the following applications are discussed: prediction and modeling of solar radiation, seizing, performances, and controls of the solar photovoltaic (PV) systems.


2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Haixiang Zang ◽  
Qingshan Xu ◽  
Pengwei Du ◽  
Katsuhiro Ichiyanagi

A modified typical meteorological year (TMY) method is proposed for generating TMY from practical measured weather data. A total of eleven weather indices and novel assigned weighting factors are applied in the processing of forming the TMY database. TMYs of 35 cities in China are generated based on the latest and accurate measured weather data (dry bulb temperature, relative humidity, wind velocity, atmospheric pressure, and daily global solar radiation) in the period of 1994–2010. The TMY data and typical solar radiation data are also investigated and analyzed in this paper, which are important in the utilizations of solar energy systems.


1960 ◽  
Vol 41 (8) ◽  
pp. 403-405 ◽  
Author(s):  
T. L. Noffsinger ◽  
F. K. Nunns

The proportion of the incident solar energy used in the evapotranspiration process is a measure of the water requirement of plants. It has been found that in Hawaii approximately 60 per cent of the insolation is used in evapotranspiration during a 12-mo period of alfalfa production. Monthly water-requirement estimates were made from the empirical equationwhere W = water requirement in inches per month, and S = solar radiation in calories per square centimeter per month.


2012 ◽  
Vol 135 (2) ◽  
Author(s):  
Orhan Ekren

Characteristics of site-specific solar irradiation is required to optimize a solar energy system. If no tracking system is used, the amount of electricity or heat produced by solar energy depends on the total solar radiation on a tilted surface. Although pyranometer measures direct plus diffuse solar radiation on a horizontal surface, there are many locations where diffuse radiation is not measured. Also, diffuse radiation is necessary to determine the total radiation on a tilted surface. Therefore, in this study, new correlations for diffuse solar radiation is proposed as a function of atmospheric parameters for Urla (Izmir, Turkey). After applying the statistical procedure on the measured data, seven new correlations are proposed for the ratio of hourly average diffuse and total radiation. Also, the ratio of monthly average daily diffuse and total radiation for this region is proposed.


2021 ◽  
Vol 9 (2) ◽  
Author(s):  
Mohammed Ali Jallal ◽  
◽  
Samira Chabaa ◽  
Abdelouhab Zeroual ◽  
◽  
...  

Precise global solar radiation (GSR) measurements in a given location are very essential for designing and supervising solar energy systems. In the case of rarity or absence of these measurements, it is important to have a theoretical or empirical model to compute the GSR values. Therefore, the main goal of this work is to offer, to designers and engineers of solar energy systems, an appropriate and accurate way to predict the half-hour global solar radiation (HHGSR) time series from some available meteorological parameters (relative humidity, air temperature, wind speed, precipitation, and acquisition time vector in half-hour scale). For that purpose, two intelligent models are developed: the first one is a multivariate dynamic neural network with feedback connection, and the second is a multivariate static neural network. The database used to build these models was recorded in Agdal’s meteorological station in Marrakesh, Morocco, during the years of 2013 and 2014, and it was divided into two subsets. The first subset is used for training and validating the models, and the second subset is used for testing the efficiency and the robustness of the developed models. The obtained results, in terms of the statistical performance indicators, demonstrate the efficiency of the developed forecasting models to accurately predict the HHGSR parameter in the city of Marrakesh, Morocco.


Author(s):  
Akram Gasmelseed

In recent years, computer simulation has become a standard tool for analyzing solar energy systems. The interaction of light with nanoscale matter can provide greater functionality for photonic devices and render unique information about their structural and dynamical properties. As the field of nanophotonics continues to experience phenomenal growth at both the fundamental research and applications level, computational modeling is essential both for interpreting experiments and for suggesting new directions – for example, in designing of thin-film photovoltaic cells. The demand for computer simulation continues to increase as researchers and developers tackle the tough challenges of designing new generation devices and optimizing current generation devices. This chapter is devoted to the development and application of the Finite-Difference Time-Domain (FDTD) method to solar energy systems. In addition, new models covering the latest advances in nanophotonics technologies, as well as key improvements to the numeric solvers and new usability features, are introduced in this chapter.


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