Energy is a key condition to guarantee access to clean water, sanitation, schooling and business in developing countries and represents a key factor for growth and development. From a general point of view, it is still debatable whether access to affordable, reliable, safe and clean energy should be considered a human right or an instrumental right, as fundamental needs may be guaranteed through energy. However, not only the clear correlation patterns between modern energy and economic and human development, but also the strong evidence on the causal relationship of access to modern energy on welfare and quality of life are sufficient elements to clearly underline the crucial role of access to modern energy in sustainable development. The text of The Milan Charter, cultural legacy of Expo Milano 2015, is available at the end of the book.