ABSTRACT
This chapter provides an introduction to the concepts of energy: what it is, how different aspects of it were discovered over centuries of time, and what the different forms and sources of energy are. It discusses the various ways that energy can be transported and how it can be converted from one form to another. The heat energy from the sun that reaches the earth is only one-thousandth of one-millionth of the heat produced by the sun. Sunlight, or solar energy, can be used directly for heating and lighting homes and other buildings, for generating electricity, and for hot-water heating, solar cooling, and a variety of commercial and industrial uses. The sun's heat also drives the wind, whose energy is captured with wind turbines. Energy is constantly being transported from place to place and transferred between objects. When an object that possesses energy moves from one place to another, it transports its energy with it.
