Earth's climate is undergoing many changes. This book discusses the importance of alternative and renewable energy. Recent researches have shown the impact of human action on the climate of the planet. Consequences of this include higher temperatures and escalation of extreme weather events such as hurricanes. This situation opens up more than a few possibilities for what is now called "green" or low carbon economy. This means creating new businesses and industries geared to develop products and services with lower utilization of natural resources and lesser greenhouse gases emission. Within this form of business, biofuels are extremely significant and the primary focus of this book. It deals with various topics like first generation ethanol formation from starch and sugar raw materials, developing efficient techniques for producing second-generation ethanol from diverse types of lignocellulosic materials and the diverse uses for ethanol. This book presents some useful information regarding this field for its readers.