What Does Energy Mean?
Energy is a term that has several definitions, with the most basic and fundamental one being "the ability to do work."
As a broad term, it can apply to a number of different actions and processes. It could, for instance, refer to the electricity that activates a machine, the physical exertion involved in completing a task, or the heat that travels through an HVAC system.
Safeopedia Explains Energy
Energy is a broad term whose definition varies depending on the context. In physics, for instance, energy is the potential ability for something to work, whether through chemical processes, heating, or electric current.
Different Forms of Energy
Energy can be divided into two categories: kinetic (working) energy and potential (stored) energy. But each of these categories contain multiple types of energy.
- Electrical energy delivered by tiny charged particles called electrons
- Radiant (light) energy, an electromagnetic energy that travels in transverse waves such as visible light, radio waves, x-rays, and gamma rays
- Thermal (heat) energy generated by the movement of atoms and molecules
- Motion, with faster movements representing greater energy
- Sound energy, the movement of energy through substances in longitudinal waves, produced when a force causes an object to vibrate
- Chemical energy stored in the bonds of atoms and molecules (e.g. coal, petroleum, natural gas)
- Mechanical energy stored in objects by tension (e.g. compressed springs, stretched rubber bands)
- Nuclear energy stored in the nucleus of an atom
- Gravitational energy stored in an object at height (the heavier and higher the object, the more stored energy it has)
Renewable and Non-Renewable Energy Sources
As the name implies, non-renewables are materials that become used up when they release energy. For example, gas-powered vehicles operate in part by causing gasoline to combust and using the resulting energy, but it can no longer be used to produce energy after the combustion process.
Other types of non-renewable energy sources include natural gas, coal, hydrocarbon gas liquids, and nuclear energy.
Renewable sources of energy, on the other hand, can be used repeatedly. The water used to generate hydropowered electricity, for instance, does not get used up by that process. Other renewables include solar, wind, biomass from plants, and geothermal energy. Renewable energy sources are mainly used to generate electricity and heat.