Solar Thermal Systems: Components and Applications—Introduction

This article is the introduction of the volume on “Solar Thermal Systems: Components and Applications.” It initially examines energy-related environmental problems, which include acid rain, ozone layer depletion and global climate change, and how renewable energy technologies can be used to avoid these problems. Subsequently, the article examines the environmental characteristics of solar energy in terms of basic relations used to determine the position of the sun on the sky. Therefore, the article includes an analysis of the equation of time, longitude correction, solar angles, the incidence angle for fixed and moving surfaces, and finally presents easy ways to determine the basic sun angles using sun path diagrams. This is followed by an analysis of the solar radiation and, in particular, thermal radiation and transparent plates, which are two subjects that are of interest to the people dealing with the design of solar systems. Finally, the solar resource is examined. The operation of solar collectors and systems depends on the solar radiation input and the ambient air temperature and their sequences. These and other meteorological parameters are usually provided in terms of the typical meteorological year and the generation of such years from raw data is given.