Advances in Energy Systems and Technology: Volume 5 present articles that provides a critical review of specific topics within the general field of energy. It discusses the fuel cells for electric utility power generation. It addresses the classification of fuel cell technologies. Some of the topics covered in the book are the major components of the fuel cell; the phosphoric acid fuel cells; molten carbonate fuel cells; solid oxide fuel cells; electric utility fuel cell systems; and the integration within fuel cell power plants. The analysis of the solar ponds is covered. The operational problems with salt-gradient solar ponds are discussed. The text describes the membrane-stratified solar ponds. A study of the household demand for conservation is presented. A chapter is devoted to the construction of the insulation index. Another section focuses on the use of Box-Cox transform for both dependent and explanatory variables. The book can provide useful information to scientists, engineers, students, and researchers.