Energy is needed to meet the subsistence requirement as well as to meet the demand of economic growth and development. Per capita consumption of energy is a measure of physical quality of life. While the production and use of energy creates environmental impacts ranging from local to global in nature. This book primarily deals with modelling of energy and environment for sustainable development using systems approach. This book has been essentially designed to study the dynamic behaviour of energy and environment systems to aid in energy and environmental policy planning. The unique feature of this book is that it considers modelling of energy and environment with micro and macro level applications for developing countries using both optimisation and simulation techniques. This book can be used as a text for the courses on energy and environmental systems engineering, renewable energy, and environmental systems engineering. Practising energy and environmental engineers and energy policy planners will find this book as an excellent reference.