The current global energy use, with its overwhelming dependence on fossil fuels, has taken global warming to dangerous levels. Climate change is already hitting us hard, through adverse effects on global food availability, biodiversity, rising sea levels and extreme weather events, such as hurricanes and floods. In the last decade, a major transformation-the transition to clean, affordable and sustainable energy from the sun and the wind-is beginning to address these challenges. Fossil Free provides a concise introduction to the challenges, realities and complexities of the global and local energy industry, as well as the trends and forces driving the energy transition. It explains how improved electricity infrastructure, decentralized smart grids, electric vehicles, energy storage and market design are already providing clear pathways for the transition towards green, efficient, affordable and secure renewable energy across the energy-use chain: extraction, conversion, transmission, distribution and end use. For over a decade, Sumant Sinha has had a ringside view of the energy scenario.