This book began by outlining why energy supply infrastructure provision is a priority, covering issues of social cohesion, economic growth, poverty, and energy security as key services that energy (infrastructure) provides. However, why should energy supply infrastructure be provided and what are the influences that affect its provision? In Part I (Chapter 2), I started off this book by questioning the assumptions and reasoning behind energy supply infrastructure provision. The underpinning assumptions of five theoretical perspectives were specifically considered: the techno-economic paradigm; social psychology; socio-technical transitions; theories of social practices; and institutional theory were explored. The individualistic approaches of techno-economics and social psychology focus on rational choice and the contextual social norms of the political actors and policy makers, and thereby give little consideration to the role of social structures and contexts. The structural approach of socio-technical transitions focuses on socio-technical rules (and how systems are organized within social contexts) with less consideration on the role of the individual choice and (un)conscious decision making. The social practices and institutional perspectives focus on practices (doings) and institutional rules respectively. These both operate on the meso level, and hence operate at the middle ground between individuals (micro) and social structures (macro), in terms of units of analysis and foci of investigation. Indeed, as part of the important learnings as evidenced in Part II, Chapter 3, the individualistic perspectives (techno-economics and social psychology) helped in explaining the findings on the role of the individual as energy users in effecting energy systems change. Socio-technical transitions helped in understanding moments of resource transitions. Institutional theory helped in understanding the key institutional influences on changes in energy infrastructure supply and use, while social practices helped in understanding how the practice of policy making has impacted on the Nigerian energy transitions.