What is energy?
Where does it come from?
What determines its cost?
Energy comes in many forms and is present everywhere in the world around us. Familiar examples include the heat from a fireplace, light from a reading lamp, and the motion of an automobile that we can detect directly with our senses. Less familiar are those forms of energy that are hidden from our senses and instead bound up in the potential for chemicals to react or nuclear matter to transform. As part of an outreach to the general public and K-12 educators, these web pages are intended to provide an elementary-level introduction to the subject of energy.
In our first tutorial on energy basics , we explore what energy really is and how it is related to both work and power.
For many of us, the energy we use most often is electricity. While this is a familiar source of energy, it is often misunderstood and in our second tutorial on electricity basics, we clarify how electricity works.
In our third tutorial, we consider the variety of energy forms which are categorized in terms of their sustainability. Some energy sources are characterized as non-renewable in the sense that when the Earth's resource of this energy is depleted it cannot be readily replenished. Other energy sources are referred to as renewable in the sense that they are generated continuously by the sun's energy.
Because of their continuous nature, the practical use of these renewable energy sources requires techniques to both gather and store the energy for later use. In our final tutorial, we look at some of the novel storage ideas presently being considered.