The Economic Load Dispatch (ELD) has a very important role to play in the power system. There are various methods which include conventional and non-conventional methods, like lambda iteration, etc. But now a day's soft-computing techniques are more frequently used, as they can be applied to practical applications. Eco Bat Algorithm is nature-inspired for solving CHPED (Combined Heat And PowerEconomic Dispatch) problems involving non-smooth, non-convex, and non-linear problems.CHPED problem aims to determine ideal heat and power, satisfy the constraints and minimize the overall cost of the system under consideration. Eco Bat Algorithm is an advanced form of Bat Algorithm. In this book, an attempt is made to find the minimum cost by using Eco BatAlgorithm, considering data of four, six, ten, and forty unit systems.