A Matlab GUI for Calculating the Solar Radiation and Shading of Surfaces on the Earth

Predicting the amount of solar radiation that strikes a surface is of the highest importance in several engineering applications, lust to name a few, solar radiation estimates is fundamental during the design of technologies such as: flat plates and concentrating collectors, solar energy storage devices, solar heaters, and photovoltaic systems. Furthermore, solar radiation estimates are important in energy studies for buildings, as during the cooling load calculation for air conditioning systems. The calculation of the solar radiation and shading involves many equations and a lot of influencing factors must be considered. Therefore, a Matlab GUI was developed that execute the equations and considers all the influencing factors. The program calculates the solar radiation and shadows caused by a rectangle as well as shadows on a rectangle surface caused by fins beside it. The user only has to set few values (like the location, time, etc.) and he can choose between the calculations either for a selectable time of the day or for a completely day. Then the results are plotted either in simple editor frames or in 2D- and 3D-graphics. The program also shows the results of some influencing angles subject to the location of the sun in the sky that can be helpful for many applications. Finally, on the educational side, the Matlab program can be useful for the engineering student performing some what if studies involving solar radiation. (C) 2009 Wiley Periodicals, Inc. Comput Appl Eng Educ 19: 161-170, 2011; View this article online at wileyonlinelibrary.com; DOI 10.1002/cae.20301