scholarly journals Semiparametric Semivariogram Modeling with a Scaling Criterion for Node Spacing: A Case Study of Solar Radiation Distribution in Thailand

Mathematics ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 2173
Author(s):  
Sompop Moonchai ◽  
Nawinda Chutsagulprom
Keyword(s):  
Solar Radiation ◽  
Monotonicity Condition ◽  
Ungauged Sites ◽  
Spurious Oscillation ◽  
Geostatistical Interpolation ◽  
Radiation Distribution ◽  
Parametric Functions ◽  
Close Form ◽  
Kriging Approach

Geostatistical interpolation methods, sometimes referred to as kriging, have been proven effective and efficient for the estimation of target quantity at ungauged sites. The merit of the kriging approach relies heavily on the semivariograms in which the parametric functions are prevalently used. In this work, we explore the semiparametric semivariogram where no close-form semivariogram is required. By additionally enforcing the monotonicity condition in order to suppress the presence of spurious oscillation, a scaling of the nodes of the semiparametric kriging is proposed. To this end, the solar radiation estimates across extensive but unmeasured regions in Thailand using three different semivariogram models are undertaken. A cross validation analysis is carried out in order to justify the performance of each approach. The best results are achieved by the semiparametric model with an improvement of around 7–13% compared to those obtained from the parametric semivariograms.

scholarly journals Empirical Validation of Regression Models for forecasting Global Solar Irradiance: A Case Study of Abeokuta, Nigeria

2018 ◽  
Vol 3 (1) ◽  
Author(s):  
Martins O Osifeko ◽  
Olufunmilayo I Sanusi ◽  
Olatilewa R Abolade ◽  
Sonia Iweriebor ◽  
Gbenga D Obikoya
Keyword(s):  
Solar Radiation ◽  
Mean Bias Error ◽  
Percentage Error ◽  
Bias Error ◽  
Empirical Validation ◽  
Correlation Ratio ◽  
Distribution Models ◽  
Average Value ◽  
Radiation Distribution

The performance of solar radiation distribution models is highly dependent on the location of use. This makes the need for location dependent validation necessary. An empirical validation of three solar radiation distribution models was carried out in this work using empirical data obtained from the Nigeria Meteorological Agency (NIMET). The models include the Angstrom-Prescott, Hargreaves and Garcia model. Four standard statistical tools of correlation ratio (R), mean bias error (MBE), mean percentage error (MPE), root mean square error (RMSE) were used for the validation. Results from the work reveal that the Angstrom-Prescott model had the least MBE with an average value of 0.1 making it the most reliable among the three models. In terms of MPE values, the Angstrom-Prescott model also performed best with an average MPE value of 0.1 while the Hargreaves and Garcia model had an average MPE performance of 0.2 and 0.15 respectively. In terms of the RMSE and correlation ratio, the Angstrom-Prescott model also performed better than the other two models with an average RMSE and correlation ratio of 0.3 and 0.65. This work thus reveals that, for a medium term solar radiation forecasting goal, the best regression based model that accurately predict the solar radiation distribution in Abeokuta is the Angstrom-Prescott model.

Impact on solar radiation parameters in India during COVID-19 lockdown: a case study

2021 ◽  
pp. 1-15
Author(s):  
S. M. Revathy ◽  
A. G. Rangaraj ◽  
Y. Srinath ◽  
K. Boopathi ◽  
A. Shobana Devi ◽  
...  
Keyword(s):  
Solar Radiation

Effects of aerosols on the solar radiation in mid-hill of Nepal: a case study in the Kathmandu Valley

2016 ◽  
Vol 8 (1) ◽  
pp. 54-62
Author(s):  
M. K. Thapa ◽  
B. K. Bhattarai ◽  
S. Gurung ◽  
B. K. Sapkota ◽  
K. N. Poudyal ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Kathmandu Valley

scholarly journals Optimal Design Strategy of a Solar Reflector Combining Photovoltaic Panels to Improve Electricity Output: A Case Study in Calgary, Canada

2021 ◽  
Vol 13 (11) ◽  
pp. 6115
Author(s):  
Moon Keun Kim ◽  
Khalid Osman Abdulkadir ◽  
Jiying Liu ◽  
Joon-Ho Choi ◽  
Huiqing Wen
Keyword(s):  
Solar Radiation ◽  
Electricity Generation ◽  
Low Cost ◽  
Design Strategy ◽  
Numerical Approach ◽  
Optimal Shape ◽  
Energy Technology ◽  
Experimental Database ◽  
Pv Panel

This study explores the combination of photovoltaic (PV) panels with a reflector mounted on a building to improve electricity generation. Globally, PV panels have been widely used as a renewable energy technology. In order to obtain more solar irradiance and improve electricity output, this study presents an advanced strategy of a reflector combining PV panels mounted on a building in Calgary, Canada. Based on an experimental database of solar irradiances, the simulation presents an optimal shape designed and tilt angles of the reflector and consequently improves solar radiation gain and electricity outputs. Polished aluminum is selected as the reflector material, and the shape and angle are designed to minimize the interruption of direct solar radiation. The numerical approach demonstrates the improvement in performance using a PV panel tilted at 30°, 45°, 60°, and 75° and a reflector, tilted at 15.5° or allowed to be tilted flexibly. A reflector tilted at 15.5° can improve solar radiation gains, of the panel, by nearly 5.5–9.2% at lower tilt angles and 14.1–21.1% at higher tilt angles. Furthermore, the flexibly adjusted reflector can improve solar radiation gains on the PV panel, by nearly 12–15.6% at lower tilt angles and 20–26.5% at higher tilt angles. A reflector tilted at 15.5° improves the panel’s output electricity on average by 4–8% with the PV panel tilted at 30° and 45° respectively and 12–19 % with the PV panel tilted at 60° and 75°, annually. Moreover, a reflector that can be flexibly tilted improves electricity output on average by 9–12% with the PV panel tilted at 30° and 45° and 17–23% with the PV panel tilted at 60° and 75°. Therefore, the utilization of a reflector improves the performance of the PV panel while incurring a relatively low cost.

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