Abstract
This chapter introduces to the solar energy in general and in perspective as far as the applications and utility of solar energy systems are concerned. It gives the brief overviews of all types of solar energy systems starting with their classifications followed by their modeling and optimization issues. Work sheds light on both solar thermal systems and solar photovoltaic (PV) systems. The performance measurement of these solar energy systems strongly depends on various system and operating parameters along with their ambient or climatic parameters, and it is a multi-criteria decision-making (MCDM) optimization problem. Based on the previous studies, the statistics as regards to the modeling and optimization of different solar energy systems and the basics of MCDM techniques with their classifications are discussed. The chapter ends with detailed summary with possible scope of future work on modelling and optimization of solar energy systems using various individuals plus hybrid MCDM techniques.