This book provides a thorough guide to the use of numerical methods in energy systems and applications. It presents methods for analysing engineering applications for energy systems, discussing finite difference, finite element, and other advanced numerical methods. Solutions to technical problems relating the application of these methods to energy systems are also thoroughly explored. Readers will discover diverse perspectives of the contributing authors and extensive discussions of issues including: -a wide variety of numerical methods concepts and related energy systems applications;-systems equations and optimization, partial differential equations, and finite difference method;-methods for solving nonlinear equations, special methods, and their mathematical implementation in multi-energy sources;-numerical investigations of electrochemical fields and devices; and-issues related to numerical approaches and optimal integration of energy consumption. This is a highly informative and carefully presented book, providing scientific and academic insight for readers with an interest in numerical methods and energy systems.