This book aims to describe the scientific concepts of energy. Accessible to readers with no scientific education beyond high-school chemistry, it starts with the basic notion of energy and the fundamental laws that govern it, such as conservation, and explains the various forms of energy, such as electrical, chemical, and nuclear. It then proceeds to describe ways in which energy is stored for very long times in the various fossil fuels (petroleum, gas, coal) as well as for short times (flywheels, pumped storage, batteries, fuel cells, liquid hydrogen). The book also discusses the modes of...