This book studies the principles of mechanical energy conversion used in renewable energy sources derived from air and water: wind power, tidal power, hydroelectric power, osmotic energy, ocean thermal energy and wave energy. Mechanical Energy Conversion presents twelve application exercises and their answers. They enable the reader to first understand the physical principles of mechanical energy converters and then learn the method for sizing them. The book also reinforces the concepts of fluid mechanics and hydraulic turbo machinery, which are required to solve the exercises. This book aims to instruct readers on how to design an energy system. For each renewable energy source covered - and based on the quantity of energy or power supplied - it describes the production process, explains how it works and calculates the characteristics and dimensions of its components.