This book presents insights into the thermal performance of solar thermal collectors using both computational and experimental modeling. It consists of various computational and experimental case studies conducted by the authors on the solar thermal collector system. The authors begin by developing thermal modeling using a case study that shows the effect of different governing parameters. A few more experimental cases studies follow that highlight the energy, exergy, and environmental performance of the solar thermal collector system and to examine the performance of a modified solar collector system, illustrating performance improvement techniques. Finally, application of different advanced optimization techniques such as soft computing and evolutionary methods, like Teacher Learner based Optimization (TLBO), Artificial Neural Network (ANN), Jaya algorithm, and Particle Swarm Optimization (PSO), are employed.