The main objective of this book is to develop an "Ecologically Sound Integrated Energy Plan" at district level to arrive at an optimal mix of energy sources that can meet the energy demand in a region by keeping in view the development priorities of the region. The book presents a conceptual design for energy systems which could meet demand of all sectors in a region. The proposed design in principle, supplies enough energy for the sustainable development of a region. The plan proposed is based on the Decision Support System approach (DSS) and is flexible, adaptable and ecologically sound.