scholarly journals Analysis of Measurements of Direct Normal and Global Solar Radiation for Maceió, Alagoas State, Northeastern Brazil

2020 ◽  
Vol 35 (4) ◽  
pp. 659-674
Author(s):  
José Marcelo Lopes Júnior ◽  
José Leonaldo de Souza ◽  
Ricardo Araujo Ferreira Junior ◽  
Cícero Manoel dos Santos ◽  
Gustavo Bastos Lyra ◽  
...  

Abstract Studying solar radiation is essential for human knowledge, since it is present in practically all its activities. Thus, the aim of this work was to analyze the climatic and seasonal variation of direct normal and global solar radiation in the region of Maceió, Alagoas State, Northeastern Brazil with sky conditions characterized by clearness index (Kt). The Kt was determined by the ratio between global solar irradiance and solar irradiance at the top of the atmosphere. The highest occurrences of daily direct normal solar irradiance under conditions of Kt ≥ 0.6 were recorded between 400 W m−2 and 700 W m−2 for all seasons. Under conditions of 0.4 ≤ Kt < 0.6, the daily direct normal solar irradiance occurred between 200 W m−2 and 500 W m−2 and for conditions of Kt < 0.4, its maximum value was 200 W m−2. It was observed that the levels of solar incidence in the study region depend on cloud cover conditions, with little influence of seasonality.

2019 ◽  
Vol 6 (1) ◽  
pp. 77-83
Author(s):  
Bed Raj K.C.

This paper reports the first experimental results on global solar irradiance measured at the horizontal surface since 2017 using calibrated Pyranometer-2 at Nepalgunj (Lat.28.05°N, Lon.81.62°E) which is about 150m from the sea level. This paper explains the impact of temperature, rainfall and clearness Index on the intensity of global solar irradiation. The annual average measured value of GSR 16.02 MJ/m2/day which is sufficient to promote solar active and passive solar energy technology at Nepalgunj and other similar geographic allocations. The results of this research can be utilized for the conformation of variation of solar radiation with meteorological parameters   and can be used for location of similar meteorological and geographical sites where solar data are not available.   


Author(s):  
Abdulhamid Yusuf ◽  
Hakeem Bolarinwa ◽  
Lukman Animasahun ◽  
Yinusa Babatunde

An analysis of measured global solar radiation (GR) in Osogbo (7.77oN, 4.57oE, 288m) is presented in the form of hourly average, monthly average and percentage frequency distribution. The experimental data corresponds to a year data of 2017. The results reveal that the monthly average values of daily total radiation exhibit seasonal variation with maximum value in dry season month of March (16.59MJ/m2) and minimum value in wet season month of August (8.98 MJ/m2). The annual average GR value is 14.20 MJ/m2 while the annual cumulative GR is 5122 MJ/m2. The solar radiation climate of Osogbo has also been compared to those reported for a number of locations. The percentage frequency of days possessing irradiation rate greater than 15 MJ/m2 is 14 percent whereas that possessing less than 10 MJ/m2 is 61 percent. We conclude, based upon the above analysis that Osogbo is characterized by relatively low global solar radiation.


2020 ◽  
pp. 45-52
Author(s):  
Prakash M. Shrestha ◽  
Jeevan Regmi ◽  
Usha Joshi ◽  
Khem N. Poudyal ◽  
Narayan P. Chapagain ◽  
...  

Solar radiation data are of great significance for solar energy systems. This study aimed to estimate monthly and seasonal average of daily global solar radiation on a horizontal surface in Pokhara (Lat.:28.21o N, Long.: 84o E and alt. 827 m above sea level), Nepal, by using CMP6 pyranometer in 2015. As a result of this measurement, monthly and yearly mean solar radiation values were 20.37 ±5.62 MJ/m2/ day in May, 11.37 ± 2.38 MJ/m2/ day in December and 16.82 ±5.24 MJ/m2/ day respectively. Annual average of clearness index and extinction coefficient are 0.51±0.14 and 0.53±0.31 respectively. There is positive correlation of maximum temperature and negative correlation of with global solar radiation.


2017 ◽  
Vol 10 (6) ◽  
pp. 1802
Author(s):  
Alice Dos Santos Macedo ◽  
Gilberto Fisch

Este trabalho realizou um estudo da variabilidade espacial em 2014 da irradiância solar na região de Manaus-AM, através de dados observacionais, inserido no Projeto GOAmazon 2014/15. Também, como forma complementar, foi realizada a análise da cobertura de nuvens, chuva e aerossóis e suas interrelações com a irradiância solar. Como resultado, observa-se que os menores valores médios da irradiância solar ocorreram na área urbana,o que é justificado, em parte pela urbanização que altera os fluxos envolvidos, diminuindo a irradiância solar à superfície. Os valores típicos são entre 400 e 600 Wm-2na estação chuvosa (fevereiro/março) com um desvio padrão de 200 e 380 Wm-2e entre 650 e 800 Wm-2na estação seca (agosto-setembro) com desvio padrão de 190 e 300 Wm-2. A B S T R A C T   The solar radiation is an important climatic element in the Amazon region, as it has a strong  impact for ecological (by the preservation of the biodiversity) and technological (as a renewable energy) areas. Consequently, this study contributes for these themes, conducting an observational study of the spatial variability of the solar irradiance for Manaus-AM area, with data collected during the project GOAmazon 2014/15. The cloud cover and rainfall and their relationships with solar radiation were also analysed. The maximum values observed for the wet season (february and march) are in the range 450 and 600 Wm-2 with high standart deviation (300 - 350 Wm-2 ), while they are in the range from 650 and 800 Wm-2  during the dry period (august - september) with lower standart deviation (200 - 300 Wm-2).  These values are directly associated with cloud cover and rainfall. In general, the urban area (Manaus city) showed the low values of solar radiation at the surface compared with its neighborhood, inducing a horizontal gradient of clouds/rainfall and solar energy between the city and the semi rural areas.  Keywords: piranometer, global solar radiation, cloud cover, total sky imager


2019 ◽  
Vol 9 (19) ◽  
pp. 3967 ◽  
Author(s):  
Yuzhang Che ◽  
Lewei Chen ◽  
Jiafeng Zheng ◽  
Liang Yuan ◽  
Feng Xiao

Day-ahead forecasting of solar radiation is essential for grid balancing, real-time unit dispatching, scheduling and trading in the solar energy utilization system. In order to provide reliable forecasts of solar radiation, a novel hybrid model is proposed in this study. The hybrid model consists of two modules: a mesoscale numerical weather prediction model (WRF: Weather Research and Forecasting) and Kalman filter. However, the Kalman filter is less likely to predict sudden changes in the forecasting errors. To address this shortcoming, we develop a new framework to implement a Kalman filter based on the clearness index. The performance of this hybrid model is evaluated using a one-year dataset of solar radiation taken from a photovoltaic plant located at Maizuru, Japan and Qinghai, China, respectively. The numerical results reveal that the proposed hybrid model performs much better in comparison with the WRF-alone forecasts under different sky conditions. In particular, in the case of clear sky conditions, the hybrid model can improve the forecasting accuracy by 95.7% and 90.9% in mean bias error (MBE), and 42.2% and 26.8% in root mean square error (RMSE) for Maizuru and Qinghai sites, respectively.


Sign in / Sign up

Export Citation Format

Share Document