The global shift toward sustainable energy systems represents one of the most pressing challenges of the twenty-first century, driven by increasing greenhouse gas emissions, rapid urbanization, and the intensifying impacts of climate change. Central to this transformation is the electrification of society, which is recognized as both an environmental imperative and a significant economic opportunity. This book examines the financial and regulatory dimensions of large-scale sustainable electrification, exploring how governments, corporations, financial institutions, and communities can mobilize capital and implement effective policy mechanisms to accelerate the transition. By integrating conceptual frameworks, empirical evidence, and case studies from diverse regions, the book highlights the interplay between investment strategies, governance models, and technological innovations that underpin sustainable energy adoption. It further discusses how electrification can reduce dependence on fossil fuels, enhance energy security, and support long-term economic growth while promoting broader social and environmental benefits. This book sets the stage for the broader volume, which collectively provides a comprehensive roadmap for advancing sustainable electrification in alignment with international climate and development objectives.