Radiative transfer model for ground surface irradiance estimation: clear sky

Area of Science:

• Atmospheric Physics
• Radiative Transfer Theory
• Solar Energy Modeling

Background:

• Accurate estimation of global solar irradiance is crucial for renewable energy applications and climate studies.
• Existing models often assume atmospheric homogeneity, which may not reflect real-world conditions.
• Understanding the impact of atmospheric properties on solar radiation is essential for precise energy yield predictions.

Purpose of the Study:

• To develop and validate a physical model for estimating global solar irradiance at the Earth's atmosphere surface.
• To establish relationships between radiative transfer, geographic coordinates, time, and date.
• To investigate the effects of atmospheric inhomogeneity on solar insolation.

Main Methods:

• A physical model based on the radiative transfer equation was developed.
• The discrete spherical harmonics method was employed to solve the radiative transfer equation.
• The model was applied to Dschang, Cameroon, considering an inhomogeneous atmosphere with Haze L aerosols and isotropic ground surface diffusion.

Main Results:

• The model's predictions align well with established models like Bird and Davies and Hay under clear sky conditions.
• The study quantifies the reduction in local insolation due to atmospheric inhomogeneity.
• The model demonstrates efficiency in estimating global solar radiation across different atmospheric levels and conditions.

Conclusions:

• The developed radiative transfer model provides a valuable tool for ground solar irradiance estimation.
• Atmospheric inhomogeneity significantly impacts and reduces local solar insolation.
• The model is effective for estimating global solar radiation under various atmospheric scenarios and altitudes.