Average Daily Global Radiation Research Articles

Solar Energy Potential in Pakistan: A Review

Solar Energy Potential in Pakistan: A Review

Shortwave Radiation on Horizontal and Incline Surfaces—One Year of Solar Radiation Measurements at Athalassa, an Inland Location in Cyprus

Athalassa is the main actinometric station of Cyprus and is located in the center of the island at a height of about 160 m. The station is equipped with shortwave and longwave radiation instruments. The time step of the measurements is 10 min, and hourly and daily values were derived for the period of June 2020–May 2021. The solar data underwent an extensive quality control process based mainly on the suggested tests of Baseline Surface Radiation Network (BSRN) for both the hourly and daily datasets. More than 98% of the data were within the limits recommended by the BSRN and other radiation networks. A statistical analysis of the shortwave solar radiation components was then performed. Linear and quadratic relationships were established between various radiation components, and their diurnal and monthly variability was assessed. The annual average daily global radiation amount was approximately 19 MJ/m2, whereas the amounts of horizontal beam and diffuse radiation were 12.9 MJ/m2 and 4.7 MJ/m2, respectively. Regarding the modeling of diffuse irradiance, the BRL diffuse fraction model (Boland-Ridley-Lauret) was applied. The results showed that the BRL model can satisfactorily estimate both the diffuse solar irradiance as well as the direct normal irradiance. Furthermore, the levels of the shortwave components were estimated based on the classification of four categories of the clearness index. The annual average of the direct normal beam radiation on clear days was 27.3 MJ/m2, and the direct horizontal radiation was 17.7 MJ/m2. Finally, the total energy received by an inclined surface was estimated based on measurements on the horizontal surfaces. In practice, photovoltaics were installed with an annual permanent slope of 26° with respect to the horizontal surface, and in a southern direction.

Radiação global e difusa diária na região de transição Cerrado-Amazônia brasileira

This study aimed to analyze the seasonal variations in atmospheric transmissivity and solar radiation (global and diffuse) on the horizontal surface in Sinop, Mato Grosso (MT) (11.865°S, 55.485°W, and altitude of 371 m) from 06/02/2011 to 12/31/2014. The values of diffuse radiation were measured using the Melo-Escobedo-Oliveira (MEO) shadow ring, with application of astronomical, geometric, and anisotropic correction factors. The analysis of atmospheric transmissivity was based on the classification of sky cover as cloudy, partly cloudy, partially clear, or clear. The diffuse radiation showed similar behavior to the radiation at the top of the atmosphere, reaching a maximum between October and April (rainy season), while the global radiation displayed higher levels during the dry season (May to September). The average daily global radiation ranged from 22.75±0.61 MJ m−2 d−1 in August to 16.44±1.45 MJ m−2 d−1 in January. In Sinop, cloudy and partly cloudy skies occurred on 45.6% of days and atmospheric transmissivity of global radiation was greater than 55% on 54.6% of days. The variations in diffuse radiation in the region were influenced by cloudiness and the concentration of biomass burning aerosol particles. The diffuse radiation can represent 8.02%–99.12% of the global radiation and 5.33%–29.01% of solar energy incident at the top of the atmosphere.

Off-grid rural electrification using integrated renewable energy sources

Presented in this study is an economic and technical evaluation to determine the optimal system combination for off-grid power generation based on solar, wind and biodiesel renewable energy resource. Nsukka being endowed with high intensity solar radiation, adequate wind speed and sufficient bioresource is a prospective candidate for a hybrid system. The monthly average daily global radiation ranges from 3.91kWh/m2 to 5.74kWh/m2 and the average wind speed is about 2.64m/s. This system was designed to meet the load requirement of the school with annual electrical demand of 10,163 MWh. Sensitivity analysis was carried out based on the effect of change in biodiesel fuel price and interest rates on the economic performance criteria of the optimal configuration. The optimum hybrid system is composed of 1kW capacity PV system, auto sized biodiesel generator and battery bank of 820h of autonomy. The Levelized Cost of Energy from the optimal system was found to be $0.0898/kWh based on sensitivity results. These results obtained shows that an integrated system with combination of PV, biodiesel generator and battery bank is a cost-effective alternative to grid extension which cost $0.126/kWh. The system life span is for 25years and it is sustainable, economical, technically feasible and environmentally friendly.

Sunshine-based Global Solar Radiation Modelling: Case Study of Putrajaya, Malaysia

Electricity demands are on the rise and with it, carbon dioxide emissions from many conventional power plants are increasing. In the efforts to mitigate such phenomena, the Malaysian government seeks to implement Building Integrated Photovoltaic (BIPV) projects. Early stage studies on Global Solar Radiation (GSR) have been carried out in several states in Malaysia including Penang, Kuala Lumpur and Kota Bharu. Afterward, data from the Malaysia Meteorological Department and the Malaysia National University have been used to estimate the monthly average daily global radiation in various locations in Malaysia. Putrajaya, a location which is implementing Malaysian Building Integrated Photovoltaic (MBIPV) is among the locations where a GSR study is currently absent. Conventional methods exist for GSR estimation with the aid of pyranometer. However, this method of GSR estimation is time consuming and not cost-effective practice. The main objective of this study is to estimate the GSR in Putrajaya. This is achieved in this study by utilizing sunshine-based data with calculated monthly average daily extraterrestrial radiation on a horizontal surface and monthly average maximum possible daily sunshine to plot a linearly fitted graph. Coefficients in the Angstrom-Prescott (A-P) model was generated from the plotted graph and was used for GSR estimation where a = 0.5 and b = 0.11. The mean percentage error (MPE) of the GSR estimation was found to be 3.4. Therefore, the estimation of GSR in Putrajaya have been successful for the first-time using sunshine-based data from dual locations method. The GSR estimation of Putrajaya in this study could benefit stakeholders in civil development sectors, policy and energy authorities.

A New Approach to Estimate the Distribution of Solar Radiation Using Linke Turbidity Factor and Tilt Angle

Our study aims to focus on the sunlight coming to the earth and the different intensity that has a strong relationship with the number of days in the year, and therefore we have taken these values throughout the year in the city of Biskra, Algeria. Based on the information we wanted to introduce some effects, for example, some atmospheric compounds and also the angle of inclination that receives sunlight knowing that the total sunlight is composed of two direct and diffuse compounds. Our study focuses on the creation of a mathematical model that helps us to include all the effects of atmospheric compounds, which are CO2 and O3. Finally, water vapor with the angstrom factor and all these values are within the Link Air Factor and create another mathematical model that calculates the total solar radiation as a function to direct solar radiation, and diffuse solar radiation, each of which is a function in the angle of inclination and a function in the angle of elevation of the sun and also a function in the coefficient of the atmospheric Linke. Finally, satisfactory results are obtained with the least relative errors. The predicted results were remarkably close and proportional to the changes of the solar radiation with the Link’s atmospheric factor and tilt angle. The average daily global radiation in Biskra (34.8 N latitude, 5.73 E longitude) is predicted with good estimations.

Estimating the global solar radiation in Putrajaya using the Angstrom-Prescott model

Global solar radiation (GSR) studies are essential in enhancing the use of solar PV systems especially for Building Integrated PV system (BIPV). Various studies on GSR had been carried out in Malaysia including Penang, Kuala Lumpur and Kota Bharu at the earlier stage. Afterward, data from the Malaysian Meteorological Department (MET) and the Malaysian National University were used to estimate the monthly average daily global radiation for various locations in Malaysia including Kuala Lumpur, Kuala Lumpur, Petaling Jaya, Bandar Baru Bangi, Kota Baru, Senai, Bayan Lepas, Kuching and Kota Kinabalu. GSR in Putrajaya, a location which has identified to implement Malaysian Building Integrated Photovoltaic (MBIPV) projects has yet to be estimated. The conventional method to obtain the amount of GSR at a location is to install a measuring device like a pyranometer at the site to observe and document its day-to-day recordings. However, this is a time-consuming and costly practice. The models used to estimate the GSR are usually based on astronomical factors, geometrical factors, physical factors and meteorological factors. There are numerous models used to predict GSR which can be categorized based on sunshine, cloud, temperature and other meteorological parameters. Additionally, the global solar energy models can be grouped by its modelling techniques such as linear, nonlinear, artificial intelligence and fuzzy logic modelling techniques. The reviews discovered that the models used to estimate GSR were mostly correlated to sunshine duration (SD), air temperature, relative humidity and geographical parameters like latitude, longitude and altitude. In this paper, the GSR in Putrajaya is estimated from the hourly solar radiation and daily sunshine hours data from the Malaysian Meteorological Department. The data, along with the calculated monthly average daily extraterrestrial radiation on a horizontal surface and monthly average maximum possible daily sunshine is used to plot a scatter graph that is linearly fitted. The gradient and vertical axis cut-off from the linear fit is used to obtain the coefficients in the Angstrom-Prescott (A-P) model. Subsequently, the coefficients were used to estimate the GSR in Putrajaya. In line with the government’s initiative, this study will provide an estimation of the GSR in Putrajaya where the finding will be beneficial to the stakeholders, policy maker, developer and investor and energy authority. The average monthly GSR was obtained for nine out of twelve months with highest at 21.18 MJ/m2 in March and lowest at 18.34 MJ/m2 in June.

Solar radiation exergy and quality performance for Iraq and Turkey

The present study is conducted with two primary objectives: First, a new formulation for the maximum efficiency of the solar radiation conversion is developed by considering the radiative energy transfer between two surfaces at different temperatures for a constant volume system. Second, a new methodology is introduced for estimating the exergy value of the monthly average daily horizontal global radiation, including many parameters, such as monthly average daily value of the horizontal extraterrestrial radiation, the number of sunny hours, the day length, the mean temperature and the mean wind velocity. Seven statistical parameters are used to validate the accuracy of all models. The results of the two new models are found to be more reliable than the results obtained from other models. This study, which was conducted for four locations in Iraq and Turkey. The findings would help in predicting the maximum availability of solar radiation based on weather parameters.

Statistical analysis for the characterization of solar energy utilization and inter-comparison of solar radiation at two sites in Cyprus

A statistical analysis and inter-comparison of the solar radiation at two sites in Cyprus representing two different climate regimes of the island (Athalassa-inland plain vs Larnaca-coastal location) covering the period January 2013–December 2015 is presented. Mean annual and mean monthly daily totals of the global, horizontal beam and diffuse radiation and their frequency distribution at both sites are computed and discussed. The values of skewness and kurtosis coefficients are used to define the frequency distribution type of the above radiation parameters on a monthly basis. The statistical analysis is extended to the daily clearness index (KT), diffuse ratio (KD), and the ratio of horizontal beam to global radiation (KB,G). Furthermore, the influencing factors on the magnitude of the radiation components were examined. The value of KT was used to classify three different types of days such as clear, partially cloudy and cloudy days. Then, a statistical analysis of the solar radiation components was performed. On an average annual basis, more than 80% of the days are classified as either clear or partially cloudy at both stations. Additionally, the influence of the atmospheric absorption and scattering of the solar radiation under clear skies was examined on the basis of the Linke turbidity factor (TL). The results of this analysis are used to characterize and compare the radiation regimes of the two sites. Both sites have relatively high intensity of global and direct horizontal radiation. The annual average daily global radiation intensity is 18.5MJm−2 at Athalassa and 19.9MJm−2 at Larnaca. The horizontal beam radiation is 13.1MJm−2 for Athalassa and 14.2MJm−2 for Larnaca. Therefore, the fraction of the beam component of the global radiation is comparatively high at both sites, as indicated by the annual average daily fraction which is greater than 0.600. Generally, Larnaca has slightly higher rates of global radiation than Athalassa, as indicated by the average yearly cumulative global irradiation which is 6763MJm−2 for Athalassa and 7274MJm−2 for Larnaca.

Economic feasibility of decentralized hybrid photovoltaic-diesel technology in Saudi Arabia: A way forward for sustainable coastal development

In view of growing concerns of global warming and depleting oil/gas reserves, many nations are considering use of hybrid photovoltaic-diesel technology as an option for power generation The Kingdom of Saudi Arabia has higher level of solar radiation and is a prospective candidate for deployment of solar photovoltaic systems. Literature indicates that commercial/residential buildings in the Kingdom consume about 10-45% of the total electric energy generated. The aim of this study is to analyze solar radiation data in city of Yanbu to assess the technoeconomic feasibility of utilizing hybrid photovoltaic-diesel-battery power systems to meet the load of a typical residential building. The monthly average daily solar global radiation ranges from 3.61 to 7.90 kWh/m2 . National Renewable Energy Laboratory?s HOMER software has been used in the study. The simulation results indicate that for a hybrid system, composed of 4 kWp photovoltaic system together with 10 kW diesel system, and a battery storage of 3 hours of autonomy (average load), the photovoltaic penetration is 21%. The cost of generating energy from that hybrid system has been found to be 0.180 $/kWh. With use of this hybrid system, about 2 tons per year of carbon emissions can be avoided entering into the local atmosphere. Also, for a given hybrid configuration, the operational time of diesel generators has been found to decrease with increase in photovoltaic capacity. The investigation examines impact of photovoltaic penetration on: carbon emissions, diesel fuel consumption, net present cost, cost of energy, etc.

Statistical analysis and inter-comparison of the global solar radiation at two sites in Cyprus

A statistical analysis and inter-comparison of the solar global radiation at two sites in Cyprus representing two different climate regimes of the island (Athalassa-inland plain vs Larnaca-coastal location) covering the period November 2012–July 2014 is presented. Mean annual, monthly and daily totals, the diurnal variation, frequency distribution of daily totals at both sites are computed and discussed. The validity of the Liu and Jordan approach to estimate mean hourly global radiation values is confirmed. The same type of statistical analysis was extended to the clearness index and sunshine duration. The results of this analysis are used to characterise and compare the radiation regimes at the two sites. The two sites are characterised by relatively high global and horizontal beam radiation intensities. The annual average daily global radiation intensities exceed the value of 18.5 MJ m−2 at the two sites, whereas the horizontal beam radiation is 11.5 MJ m−2 for Athalassa and 11.9 MJ m−2 for Larnaca, respectively. Consequently, the fraction of the beam component of the global radiation is relatively high at both sites, viz., the annual average daily fraction is > 0.600 at the two sites. Comparing the two sites it seems that Larnaca has slightly higher rates of global radiation than Athalassa, since the average yearly cumulative global irradiation is 6835 MJ m−2 for Athalassa and 7183 MJ m−2 for Larnaca. The annual coefficients of Angstrom formula were estimated using daily clearness index and relative sunshine data. The coefficient values for both stations were close to each other.

Predictions of solar radiation distribution: Global, direct and diffuse light on horizontal surface

Solar radiation models for predicting the average daily and hourly global radiation, direct and diffuse radiation are discussed in this paper. The average daily global radiation in Ghardaia (32.38 N latitude, 3.82 E longitude) is predicted. Estimations of monthly average hourly global radiation are considered. We have developed this correlation using the sunlight and global radiation data from one year location around the weather station in Ghardaia. Two predictions of solar radiation distribution: direct and diffuse light on a horizontal area models, are reviewed to predict the hourly irradiation of Ghardaia utilizing the approach such as regression models. Comparisons between model predictions with measured data are made.

PREDICTING SOLAR RADIATION FOR TROPICAL ISLANDS FROM RAINFALL DATA

There are many correlations developed to predict incident solar radiation at a given location developed based on geographical and meteorological parameters. However, all correlations depend on accurate measurement and availability of weather data such as sunshine duration, cloud cover, relative humidity, maximum and minimum temperatures etc, which essentially is a costly exercise in terms of equipment and labour. Sri Lanka being a tropical island of latitudinal change of only 30 along the length of the country, the meteorological factors govern the amount of incident radiation. Considering the cloud formation and wind patterns over Sri Lanka as well as the seasonal rainfall patterns, it can be observed that the mean number of rainy days can be used to predict the monthly average daily global radiation which can be used for calculations in solar related activities conveniently.

PREDICTING SOLAR RADIATION FOR TROPICAL ISLANDS FROM RAINFALL DATA

There are many correlations developed to predict incident solar radiation at a given location developed based on geographical and meteorological parameters. However, all correlations depend on accurate measurement and availability of weather data such as sunshine duration, cloud cover, relative humidity, maximum and minimum temperatures etc, which essentially is a costly exercise in terms of equipment and labour. Sri Lanka being a tropical island of latitudinal change of only 30 along the length of the country, the meteorological factors govern the amount of incident radiation. Considering the cloud formation and wind patterns over Sri Lanka as well as the seasonal rainfall patterns, it can be observed that the mean number of rainy days can be used to predict the monthly average daily global radiation which can be used for calculations in solar related activities conveniently.

New correlations for estimation of monthly average daily solar radiation on a horizontal surface using meteorological data

This study deals with the estimation of monthly average daily global solar radiation incident on a horizontal surface at a location using meteorological data for different cities of Andhra Pradesh state. The regression equations of two types of models are developed for various locations of the state having varied climatic regions using measured meteorological parameters obtained from different measuring stations. Parameters such as the latitude and height of the location, maximum and minimum temperature and relative humidity are considered to develop linear and quadratic regression equations to estimate the monthly average daily global radiation. The estimated values are compared with measured data and with other theoretical models in terms of mean percent errors calculated using recognised statistical criteria of MBE, MABE, MPE and RMSE. The proposed quadratic model performs better than the proposed linear models and shows good agreement with the long-term pyranometer data of various locations with a deviation of less than 10%. In comparison with other theoretical models presented so far, the suggested models are expected to perform with a higher degree of accuracy.

Study of the Intensity of Global Solar Radiation Incident in Suan Sunandha Rajabhat University

Solar radiation is one of mains alternative energy, widely used in present day. Measure solar radiation accurately is an essential for planning in application of used. Universities are the places that have used significant of energy all year long. Therefore, long-term measured solar radiation data is important, for understand in both quantity and variation in time period, for application of the alternative energy in future. The main objective of this research is to investigate solar energy potentials of Suan Sunandha Rajabhat University, Bongkok, Thailand (Latitude 13.46°N, Longitude 100.31°E). A station for solar radiation was installed at Suan Sunandha Rajabhat University. The main equipment is composed of two parts: 1) a pyranometer from Kipp & Zonen Ltd., model CMP11, and 2) a digital data logger from Measurement Systems Ltd. model DX2000. The pyranometer is permanently installed on the top of a building. The data logger is keeping clean and safe inside the building. To analyze the values of the global solar radiations, the computer source code is written in Interactive Data Language version 6.1 (IDL6.1). The results show the variation of the average hourly global irradiance is about 800-900 W/m2 at 12:00 UTC. The maximum monthly average daily global radiation is 21.5 MJ/m2-day in April. The yearly average daily radiation at Suan Sunandha Rajabhat University is found to be 16.55 MJ/m2-day. The information from the monthly and yearly global radiation has relatively high solar energy potentials. Finally, the solar radiation database was also developed for use in solar energy applications in Suan Sunandha Rajabhat University and neighbor areas.

Estimation of horizontal diffuse solar radiation from common meteorological parameters: a case study for Jeddah, Saudi Arabia

The measured data of global and diffuse solar radiation on a horizontal surface, number of sunshine hours, mean daily ambient temperature, maximum and minimum ambient temperatures, relative humidity and amount of cloud cover, for Jeddah (latitude 21° 42′ 37″ N, longitude 39° 11′ 12″ E), Saudi Arabia for the period (1996–2006) are analysed. The data are employed to develop empirical correlations between the monthly average daily diffuse fraction (H d /H) or diffuse transmittance (H d /H 0) and various meteorological parameters such as relative number of sunshine hours (s/s 0), ambient temperature T, relative humidity R h and amount of cloud cover c w. The derived correlations are evaluated by making comparisons between measured and calculated values of monthly average daily diffuse radiation H d. All the proposed correlations are found to be able to predict the monthly and annual averages daily diffuse radiation with excellent accuracy. It is also inferred that, if the data of the monthly average daily global radiation H and number of bright sunshine hours s are not available, the values of H d for the hot-humid zone of Saudi Arabia can be estimated with a reasonable accuracy from the correlations between H d /H 0 and the mean daily ambient temperature T.

An approach for estimating average daily global solar radiation from cloud cover in Thailand

Global solar radiation is important for solar energy applications. In this work, an approach for estimating monthly average daily global solar radiation in Thailand was proposed. In developing this approach, cloud cover and global solar radiation measured at 24 sites in Thailand were analyzed. According to the analysis, values of normalized monthly average daily global radiation were correlated with those of monthly average cloud cover. Then linear equations relating the normalized global radiation with the cloud cover were formulated. In the next step, the values of the slope and intercept of the equations from all sites were determined. These values were interpolated to cover the entire areas of the country and they were presented as contour maps. In the final step, a general empirical equation for estimating the average daily global radiation from the cloud cover was proposed. The model coefficients for the entire areas of the country were obtained from the maps. For the validation, the general equation was used to calculate average daily global radiation at 4 sites whose data were not used in the model development process. Finally, the results were compared with the measurements and they were in good agreement.

General formula for the estimation of global solar radiation on earth’s surface around the globe

The data such as global solar radiation, air temperature, relative humidity, wind and moisture, was collected from 875 stations around the globe. Of which data from 210 stations fairly spread on the earth surface was used to develop the formula for estimating the monthly average daily global radiation on a horizontal surface. In this study, using air temperature, relative humidity, wind, moisture and few derived parameters as independent variables, the most accurate equations have been obtained. The results show that the general formula developed could be used for the estimation of solar radiation with the local site parameters. Thus developed models have been validated with remaining 665 data sites. Finally two candidate models have been proposed. These models are capable of covering 50% of the land area on earth surface between latitude ±30°, enabling estimation accuracy to 93% of sites, with an estimation error (RMSE) limiting to 15%. Thus it is envisaged that, the proposed equations (models) can be used to estimate the monthly average daily global solar radiation in area where the radiation data is missing or not available. This helps in assessing the solar energy potential over necessitated area.

Solar radiation models-A review

Solar radiation models for predicting the average daily and hourly global radiation, beam radiation and diffuse radiation on horizontal surface are reviewed in this article. Estimations of monthly average hourly global radiation from daily summations are discussed. It was observed that Collares-Pereira and Rabl model as modified by Gueymard (CPRG) yielded the best performance for estimating mean hourly global radiation incident on a horizontal surface for Indian regions. Estimations of monthly average hourly beam and diffuse radiation are discussed. It was observed that Singh-Tiwari and Jamil-Tiwari both models generally give better results for climatic conditions of Indian regions. Therefore, their use is recommended for composite climate of Indian regions. Empirical correlations developed to establish a relationship between the hourly diffuse fraction and the hourly clearness index using hourly global and diffuse irradiation measurements on a horizontal surface are discussed. Fifty models using the Angstrom–Prescott equation to predict the average daily global radiation with hours of sunshine are considered. It was reported that Ertekin and Yaldiz model showed the best performance against measured data of Konya, Turkey. Copyright © 2010 John Wiley & Sons, Ltd.