This book is a must-read for those interested in the aging phenomenon of materials used in new energy systems, such as photovoltaic and electric vehicles. It provides a fundamental framework for this topic and important basic data and references for insulation materials used in these systems. It covers the aging of photovoltaic systems installed in different environments, including space, as well as the aging of the discharge present in the drive motors of electric vehicles. This book is suitable for researchers and students interested in green energy systems and can be used for teaching, research, and science popularization.