Estimation of monthly global solar radiation over twelve major cities of Libya

This study aims to estimate monthly averaged daily horizontal global solar radiation.Measured climatological data collected at twelve major cities located across Libya’s map were used to establish 7 different empirical models.The empirical coefficients of the models were calculated using the least square method.The accuracy of the models was evaluated using different statistical criteria such as Taylor diagram,mean absolute percentage error,MAPE,and root mean square error,RMSE.The results indicated that the sunshine duration-based models are more accurate than air temperature-based models,and the best performance was obtained by the quadratic regression model for all twelve Libyan cities.Moreover,this regression model can be used for the prediction of monthly mean horizontal global solar radiation at a specific site across Libya’s regions with minimum error.Furthermore,the results of the global solar irradiance produced by this method can be used for designing solar systems applications.

Modification of the SUNFLUX Solar Radiation Scheme with a New Aerosol Parameterization and Its Validation Using Observation Network Data

SUNFLUX is a fast parameterization scheme for determination of the solar radiation at the Earth＇s surface. In this paper, SUNFLUX is further modified in the treatment of aerosols. A new aerosol parameterization scheme is developed for five aerosol species. Observational data from Baseline Surface Radiation Network （BSRN）, Surface Radiation Budget Network （SURFRAD） and Aerosol Robotic Network （AERONET） stations are used to evaluate the accuracy of the original and modified SUNFLUX schemes. General meteorological data are available at SURFRAD stations, but not at BSRN stations. Therefore, the total precipitable water content and aerosol data are obtained from AERONET stations. Fourteen stations are selected from both BSRN and AERONET. Cloud fraction data from MODIS are further used to screen the cloud. Ten-year average aerosol mixing ratios simulated by the CAM-chem system are used to calculate the fractions of aerosol optical depth for each aerosol species, and these fractions are further used to convert the observed total aerosol optical depth into the components of individual species for use in the evaluations. The proper treatment of multiple aerosol types in the model is discussed. The evaluation results using SUNFLUX with the new aerosol scheme, in terms of the BSRN dataset, are better than those using the original aerosol scheme under clear-sky conditions. However, the results using the SURFRAD dataset are slightly worse, attributable to the differences in the input water vapor and aerosol optical depth. Sensitivity tests are conducted to investigate the error response of the SUNFLUX scheme to the errors in the input variables.

Application of recording films of solar radiation for environmental and ecological research

Global solar radiation is recorded by fading of the colored film into which azo-dye is impregnated with use of organic solvent. Oil Red O, Sudan I, Sudan IV and Pyridylazonaphthol are used as the azo dye. These films can be applied to measure the solar radiation in many kinds of environmental or ecological conditions. The merits of the film compared with usual measurements are to be: unnecessary of any electric sources; cheap and mass-productive easily; suitable to integrate solar radiation for long time; easy dealing in out-door or underwater conditions; possible to use on leaves of any plants because of light weight; possible to use in a lot of points at the same time.

An Advanced Simple Method for Generating Synthetic Average Instant Hourly Solar Energy

The main objective of this study is to generate accurate synthetic hourly solar radiation data by using an easily accessible open source data.In this regard,a new approach is proposed for estimation of synthetic hourly global solar radiation during the day by utilizing only annual solar energy data.First time in literature,a model has been developed for prediction hourly and daily solar radiation based on annual solar energy parameter in this study.Parameters of the model were generated and tested for Turkey and one of them was presented as a case study within this paper.Long term measured hourly horizontal solar irradiance data from a network of Turkish meteorological stations was used to calibrate the model function.The predictions are compared with the solar data available in literature for Turkey.The advanced simple new model is utilized in open source computer program and has the potential to be adapted to other countries.

Verification of Solar Energy Measurements by (ERA-5) and Its Impact on Electricity Costs in North Africa

The target of this research is to estimate the distribution of global solar radiation (GSR) and reanalysis datasets (ERA-5) for development of PV cost reduction and predict of level cost energy over five countries in North Africa during the period time from 2011 to 2020. The effectiveness of reanalysis datasets (ERA-5) for North African countries was evaluated against high-quality surfaces measured using statistical analysis. The average values of mean bias error (MBE), root mean square error (RMSE) and mean absolute error (MAE) of the reanalysis data of solar radiation vary from 0.079 to 0.222, 0.055 to 0.178, and 0.0145 to 0.198 respectively during the period time in the present research. The correlation coefficient (R2) varies from 0.93 to 99% in the present research. North African countries are among the most vulnerable regions to the potential impacts of climate change. The increasing impact of climate change shows the need to build up a reliable energy mix and improve the resilience of existing and new energy systems. The development of PV cost reduction and the predicted of level cost of energy (LCOE) are discussed and used one PV Module to calculate the total cost for five countries in North Africa. This research’s objective is to provide a reliable representation of the world’s solar radiation to aid in the use of solar energy in all sectors.

Influence of complex topography on global solar radiation in the Yangtze River Basin

Global solar radiation（GSR） is the most direct source and form of global energy, and calculation of its quantity is highly complex due to influences of local topography and terrain inter-shielding. Digital elevation model（DEM） data as a representation of the complex terrain and multiplicity condition produces a series of topographic factors（e.g. slope, aspect, etc.）. Based on 1 km resolution DEM data, meteorological observations and NOAA-AVHRR remote sensing data, a distributed model for the calculation of GSR over rugged terrain within the Yangtze River Basin has been developed. The overarching model permits calculation of astronomical solar radiation for rugged topography and comprises a distributed direct solar radiation model, a distributed diffuse radiation model and a distributed terrain reflectance radiation model. Using the developed model, a quantitative simulation of the GSR space distribution and visualization has been undertaken, with results subsequently analyzed with respect to locality and terrain. Analyses suggest that GSR magnitude is seasonally affected, while the degree of influence was found to increase in concurrence with increasing altitude. Moreover, GSR magnitude exhibited clear spatial variation with respect to the dominant local aspect; GSR values associated with the sunny southern slopes were significantly greater than those associated with shaded slopes. Error analysis indicates a mean absolute error of 12.983 MJm-2 and a mean relative error of 3.608%, while the results based on a site authentication procedure display an absolute error of 22.621 MJm-2 and a relative error of 4.626%.

Correlations for estimating solar radiation using sunshine hours and temperature measurement in Osogbo, Osun State, Nigeria

In this study, the global solar radiation on horizontal surface in Osogbo, Osun state, Nigeria was analyzed using ll-year data （1997-2007）. Correlations using linear and quadratic expressions were developed to relate the global solar radiation on horizontal surface based on relative sunshine hours and temperature measurements for evaluating the monthly average daily global solar radiation. The calculated monthly clearness index values indicate that the prevailing weather condition in Osogbo is heavily overcast. All the developed quadratic correlations gave better correlation coefficients （0.834, 0.872 and 0.823 respectively） than the linear models. However, the Hargreaves and Samani related based quadratic model gave the best among the three developed quadratic expressions and is therefore suggested for estimating the monthly global radiation in this site and its surroundings.

Smart model for accurate estimation of solar radiation

Prediction of solar radiation has drawn increasing attention in the recent years.This is because of the lack of solar radiation measurement stations.In the present work,14 solar radiation models have been used to assess monthly global solar radiation on a horizontal surface as function of three parameters:extraterrestrial solar irradiance(),duration sunshine()and daylight hours().Since it has been observed that each model is adequate for some months of the year,one model cannot be used for the prediction of the whole year.Therefore,a smart hybrid system is proposed which selects,based on the intelligent rules,the most suitable prediction model of the 14 models listed in this study.For the test and evaluation of the proposed models,Tamanrasset city,which is located in the south of Algeria,is selected for this study.The meteorological data sets of five years(2000–2004)have been collected from the Algerian National Office of Meteorology(NOM),and two spatial databases.The results indicate that the new hybrid model is capable of predicting the monthly global solar radiation,which offers an excellent measuring accuracy of values ranging from 93%to 97%in this location.

Research exploring greenhouse environment control over the last 50 years

Environments do not exist in isolation.Their main components in greenhouse systems are plants.Without consideration of plants,analysis of greenhouse environments and environmental control of greenhouses can be accomplished,although it is not simple to achieve.Initial attempts were undertaken to analyze greenhouse environments and then reproduce them.Ventilation rate effects on plant photosynthesis in a growth chamber were reported in 1966.Computer simulations then became a main subject of research.The first dynamic computer simulation of a greenhouse environment including plants was published in 1971.According to innovations of computer technology,the use of minicomputers and microcomputers spread in many areas.By measuring the net photosynthesis of lettuce plants grown under artificial lighting,air temperature was optimized using a minicomputer with the hill-climbing method.The method was designated as the Speaking Plant Approach to environment control(SPA).After the author developed the first reported environmental control system in Japan,systems using microcomputers spread widely for greenhouse environmental control.Knowledge-based expert systems were tested for plant management.Also,a machine vision system was developed to detect critical moments for watering of muskmelon plants.The first feed-forward control method for greenhouses with a large heat mass was reported.Then space farming was tested in 1996 to assess gravity effects on plants.Energy-saving aspects such as solar sterilization,ground heat storage system,and storage using phase change material(PCM)have been reported.Defects of ordinary solarimeters were reported in 2008 along with an approach to estimate evapotranspiration in a greenhouse without the effect of so-called cosine law.Later,this technique was expanded to estimate photosynthesis of the plant canopy in a greenhouse using newly developed sensor units.