With ever increasing concern on environmental protection and energy conservation, there is a fast growing interest in electric vehicles (EVs) from automakers, governments and customers. As electric propulsion is the core of EVs, there is a pressing need for researchers to develop advanced electric motor drives for various classes of EVs, including the battery, hybrid and fuel cell vehicles. Such issues are addressed in this book. The development and use of a fuel cell based power system for propulsion of electric aircrafts is discussed. A study done on the flight mechanics of the new aircraft, to verify the new flight performance, is also examined. Electric powered two-wheelers have risen in popularity in China over the past several years. This book investigates the growth of these electric two-wheelers in China and compares their environmental and safety impacts to those of alternative modes of transportation. Futhermore, the design and implementation of a hardware-in-the-loop system for the development, verification, and validation of algorithms used to construct state estimators for batteries and supercapacitors is addressed. There are several different kinds of devices that can be used to achieve electrochemical energy conversion. Some of these conversion technologies are reviewed, as well as their impact on the environment. The method used to control a power-train of a hybrid electric vehicle is discussed as well as how both the engine and the electric machine may achieve respective higher efficiencies after using this method. The regulated and unregulated emissions of diesel engines operating on different sulfur content fuels are also looked at. Energy efficiency issues include research and development priorities, funding for climate-related efficiency programs, implementation of equipment efficiency standards, regulation of vehicle fuel efficiency, and electricity industry ratemaking for energy efficiency profitability. Such issues are addressed in this book.