Evaluation of solar energy resources by establishing empirical models for diffuse solar radiation on tilted surface and analysis for optimum tilt angle for a prospective location in southern region of Sindh, Pakistan

2015 ◽  
Vol 64 ◽  
pp. 1073-1080 ◽  
Author(s):  
Shahnawaz Farhan Khahro ◽  
Kavita Tabbassum ◽  
Shahnawaz Talpur ◽  
Mohammad Bux Alvi ◽  
Xiaozhong Liao ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Solar Energy ◽  
Tilt Angle ◽  
Empirical Models ◽  
Southern Region ◽  
Energy Resources ◽  
Diffuse Solar Radiation ◽  
Tilted Surface

Developing and Evaluation of Various Correlations for Diffuse Solar Radiation for Urla (Izmir, Turkey)

2012 ◽  
Vol 135 (2) ◽  
Author(s):  
Orhan Ekren
Keyword(s):  
Solar Radiation ◽  
Solar Energy ◽  
Tracking System ◽  
Diffuse Radiation ◽  
Energy System ◽  
Solar Irradiation ◽  
Total Solar Radiation ◽  
Total Radiation ◽  
Diffuse Solar Radiation ◽  
Tilted Surface

Characteristics of site-specific solar irradiation is required to optimize a solar energy system. If no tracking system is used, the amount of electricity or heat produced by solar energy depends on the total solar radiation on a tilted surface. Although pyranometer measures direct plus diffuse solar radiation on a horizontal surface, there are many locations where diffuse radiation is not measured. Also, diffuse radiation is necessary to determine the total radiation on a tilted surface. Therefore, in this study, new correlations for diffuse solar radiation is proposed as a function of atmospheric parameters for Urla (Izmir, Turkey). After applying the statistical procedure on the measured data, seven new correlations are proposed for the ratio of hourly average diffuse and total radiation. Also, the ratio of monthly average daily diffuse and total radiation for this region 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.

scholarly journals Improved empirical models for estimating surface direct and diffuse solar radiation at monthly and daily level: A case study in North China

2019 ◽  
Vol 43 (1) ◽  
pp. 80-94 ◽  
Author(s):  
Yao Feng ◽  
Dongmei Chen ◽  
Xinyi Zhao
Keyword(s):  
Solar Radiation ◽  
North China ◽  
Field Measurements ◽  
Empirical Models ◽  
Energy Utilization ◽  
Total Solar Radiation ◽  
Diffuse Solar Radiation ◽  
Precise Knowledge ◽  
The Impact

Precise knowledge of direct and diffuse solar radiation is important for energy utilization and agricultural activities. However, field measurements in most areas of the world are only for total solar radiation. The satellite-retrieved direct and diffuse solar radiation show poor performance under overcast skies. Therefore, better empirical models are needed to estimate direct and diffuse solar radiation by considering the impact of aerosols over polluted regions. A case study is conducted in North China with the ground-measured solar radiation and satellite-retrieved aerosol optical depth to improve new empirical models at monthly (from 2000 to 2016) and daily (from 2006 to 2009) level. The improved empirical models are validated using the field measurements and compared with the existing models. Results suggest that these models perform well in estimating direct solar radiation at monthly ( R2 = 0.86–0.91, RMSE = 0.76–0.83 MJ/m2) and daily ( R2 = 0.91–0.94, RMSE = 1.51–1.64 MJ/m2) level. The accuracy of estimated monthly ( R2 = 0.95–0.96, RMSE = 0.57–0.65 MJ/m2) and daily ( R2 = 0.91–0.93, RMSE = 1.09–1.15 MJ/m2) diffuse solar radiation, particularly the maximum diffuse solar radiation value, has been improved compared to the existing models. The models presented in this study can be useful in the improvement and evaluation of solar radiation dataset over polluted regions similar to North China.

scholarly journals Solar Energy Potential in Turkey

2005 ◽  
Vol 23 (1) ◽  
pp. 61-69 ◽  
Author(s):  
Havva Balat
Keyword(s):  
Solar Radiation ◽  
Solar Energy ◽  
Geographical Location ◽  
Clean Energy ◽  
Energy Resources ◽  
Solar Thermal ◽  
Energy Potential ◽  
Yearly Average ◽  
Solar Thermal Applications

In this study, the solar energy potential of Turkey was investigated. Among the alternative clean energy resources in Turkey, the most important one is solar energy. Turkey's solar energy potential has been estimated to be 26.4 million toe as thermal and 8.8 million toe as electricity. Generally, solar energy is used for heating and the consumption of solar energy has increased from 5 ktoe in 1986 to 335 ktoe in 2003. Turkey's geographical location is highly favourable for utilization of solar energy. The yearly average solar radiation is 3.6 kWh/(m2 day) and the total yearly insulation period is approximately 2460 hours, which is sufficient to provide adequate energy for solar thermal applications.

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