scholarly journals Possibilities to Estimate Daily Solar Radiation on 2-Axis Tracking Plane Using a Model Based on Temperature Amplitude

2020 ◽  
Vol 12 (23) ◽  
pp. 9909
Author(s):  
Dariusz Czekalski ◽  
Paweł Obstawski ◽  
Tomasz Bakoń
Keyword(s):  
Solar Radiation ◽  
Horizontal Plane ◽  
Strong Relationship ◽  
Empirical Models ◽  
Accurate Estimation ◽  
Estimation Errors ◽  
Coefficient Of Variability ◽  
Second Procedure ◽  
Temperature Amplitude ◽  
Parallel Measurements

Significant errors may occur when estimating daily solar radiation in central Europe using empirical models based on air temperature (especially in the winter months). The first goal of this article is to investigate to what extent it is possible to increase the accuracy of the Hargreaves and Samani model, by using the calibration dedicated for each month. We also corrected the temperature amplitudes by narrowing the daily intervals from which the minimum and maximum values were taken. The second goal of this article is to compare the precision of the daily solar radiation estimation on the horizontal plane and on the 2-axis tracking plane. The database comprises the series of parallel measurements on both planes over a period of 10 years. We considered two procedures, direct and indirect, for the 2-axis tracking plane. The second procedure, dubbed “the first estimate horizontal than calculate tracking” is based on the strong relationship between daily solar radiations on both planes. The direct procedure allows for a slightly more accurate estimation. The estimation of daily radiation on the 2-axis tracking plane reflects the measured values worse than estimation on the horizontal plane. We discovered that the increase of estimation errors on the 2-axis tracking plane, compared to the horizontal one, is proportional to the increase in the coefficient of variability of the daily solar radiations.

scholarly journals Performance Analysis of Daily Global Solar Radiation Models in Peru by Regression Analysis

Atmosphere ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 389
Author(s):  
Babak Mohammadi ◽  
Roozbeh Moazenzadeh
Keyword(s):  
Regression Analysis ◽  
Solar Radiation ◽  
Linear Regression Analysis ◽  
Global Solar Radiation ◽  
Multiple Linear Regression Analysis ◽  
Empirical Models ◽  
Estimation Errors ◽  
Proposed Model ◽  
Mean Square Errors ◽  
San Martín

Solar radiation (Rs) is one of the main parameters controlling the energy balance at the Earth’s surface and plays a major role in evapotranspiration and plant growth, snow melting, and environmental studies. This work aimed at evaluating the performance of seven empirical models in estimating daily solar radiation over 1990–2004 (calibration) and 2004–2010 (validation) at 13 Peruvian meteorological stations. With the same variables used in empirical models (temperature) as well as two other parameters, namely precipitation and relative humidity, new models were developed by multiple linear regression analysis (proposed models). In calibration of empirical models with the same variables, the lowest estimation errors were 227.1 and 236.3 J·cm−2·day−1 at Tacna and Puno stations, and the highest errors were 3958.4 and 3005.7 at San Ramon and Junin stations, respectively. The poorest-performing empirical models greatly overestimated Rs at most stations. The best performance of a proposed model (in terms of percentage of error reduction) was 73% compared to the average of all empirical models and 93% relative to the poorest result of empirical models, both at San Ramon station. According to root mean square errors (RMSEs) of proposed models, the worst and the best results are achieved at San Martin station (RMSE = 508.8 J·cm−2·day−1) and Tacna station (RMSE = 223.2 J·cm−2·day−1), respectively.

Evaluation of the Hourly Global Solar Radiation on a Horizontal Plane for Two Sites in Algeria

2014 ◽  
Vol 925 ◽  
pp. 641-645 ◽  
Author(s):  
Mohamed Salmi ◽  
Hassen Bouzgou ◽  
Yarub Al-Douri ◽  
Abdelhakim Boursas
Keyword(s):  
Solar Radiation ◽  
Gaussian Distribution ◽  
Horizontal Plane ◽  
Experimental Validation ◽  
Global Solar Radiation ◽  
Distribution Model ◽  
Experimental Assessment ◽  
Precise Prediction ◽  
Gaussian Distribution Model ◽  
Modelling Approach

We present three models for the estimation of hourly global solar radiation for two sites in Algeria, namely: Djelfa (Latitude 34.68°N, Longitude 3.25°E, Altitude 1126 (m)) and Ain Bessem (Latitude 36.31°N, Longitude 3.67°E, Altitude 629 (m)). The models are: the Gaussian distribution model, the model by Collares-Pereira-RabI and the H.A. model (Hourly absolute modelling approach). The experimental assessment was done using recorded values of the hourly global solar radiation on a horizontal plane during the period 2000-2004. The obtained results show a close similarity between the solar radiation values calculated by the three models and the measured values, especially for the first model. The experimental validation shows promising results for the estimation and precise prediction of the hourly global solar radiation.

Application Of Solar Maps In Design Of Generalposition Shading Devices

2020 ◽  
pp. 105-109
Author(s):  
Alexander T. Dvoretsky ◽  
Oleg V. Sergeichuk ◽  
Alexander V. Spiridonov
Keyword(s):  
Energy Efficiency ◽  
Solar Radiation ◽  
General Position ◽  
Horizontal Plane ◽  
Heating Period ◽  
Cooling Period ◽  
Efficiency Calculation ◽  
Shading Devices ◽  
Building Cooling ◽  
Simplified Formula

For insolation calculations and design of shading devices (SD) comprising plane sections or fins, the method based on solar maps shall be preferred because of its high descriptiveness and universality.The article describes the algorithm of design of a general-position SD using a solar map and a shade clinometer. An example of calculation of SD geometry parameters such as fin slopes with the horizontal plane and the facade plane, distance between the fins with consideration of screening of the translucent structure during the building cooling period and of transmission of solar radiation during its heating period is given in the article. A simplified formula of a general-position SD energy efficiency calculation is proposed.

Review of empirical solar radiation models for estimating global solar radiation of various climate zones of China

2019 ◽  
Vol 44 (2) ◽  
pp. 168-188
Author(s):  
Shaban G Gouda ◽  
Zakia Hussein ◽  
Shuai Luo ◽  
Qiaoxia Yuan
Keyword(s):  
Solar Radiation ◽  
Solar Energy ◽  
Computational Cost ◽  
Energy Systems ◽  
Global Solar Radiation ◽  
Empirical Models ◽  
Dew Point ◽  
Machine Learning Techniques ◽  
Accurate Information ◽  
Input Parameters

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.

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