This chapter provides an introduction to the themes discussed throughout the book which examines the evidence in respect of the transformations at the nexus of the energy system and gender roles and relations. The energy system consists of the conversion of a number of energy sources into a transportable form to the consumer who uses the energy to provide desired services, such as lighting, cooking and telecommunications. The system involves both technical aspects and people playing a variety of roles which is where gender emerges as an issue. The book uses the framework of macro (policy), meso- (organizations and institutions) and micro-households, communities or workplaces) levels of society to describe our current understanding of the gender and energy nexus.