Learn About Energy

Energy is essential. It is embodied in everything we use. To compare sources of energy effectively, we need to understand what it is and how it works.


What is Energy?

It comes from many sources and in many forms. The forms of energy are classified in two general categories: potential and kinetic. Potential energy is energy stored in an object. Chemical, mechanical, nuclear, gravitational and electrical are all stored energy. Kinetic energy does the work. Light, heat, motion and sound are examples of kinetic energy.

Here’s a simple example: Stretching a rubber band gives it the potential to fly. The tension created from the stretching is potential mechanical energy. When the rubber band is released, it flies through the air using motion (kinetic energy). The process of changing energy from one form into another is called energy transformation. The rubber band is transformed from potential energy into kinetic energy.

Systems convert energy at various rates of efficiency. Water turbines, for example, are very efficient, while combustion engines are not. Engineers and physicists constantly work to develop systems with high energy-conversion efficiency.