The following narrative is a summary in the Wikipedia Web encyclopedia. For broader details refer to www.wikipedia.com. In order to differentiate forms of alternative energy sources, it is important to understand the various definitions of energy. Energy in physics, chemistry, and nature occurs in numerous forms, all of which imply similar connotations to the ability to perform work. In physics and other sciences, energy is a scalar quantity that is a property of objects and systems and is conserved by nature.

Several different forms of energy, including kinetic energy, potential energy, thermal energy, gravitational energy, electromagnetic radiation energy, chemical energy, and nuclear energy have been defined to explain all known natural phenomena.

Conservation of Energy

Energy is transformation from one form to another, but it is never created or destroyed. This principle, the law of conservation of energy, was first postulated in the early nineteenth century and applies to any isolated system. The total energy of a system does not change over time, but its value may depend on the frame of reference. For example, a seated passenger in a moving vehicle has zero kinetic energy relative to the vehicle but does indeed have kinetic energy relative to Earth.