The following outline is provided as an overview of and topical guide to energy:

Energy – in physics, this is an indirectly observed quantity often understood as the ability of a physical system to do work on other physical systems.[1][2] Since work is defined as a force acting through a distance (a length of space), energy is always equivalent to the ability to exert force (a pull or a push) against an object that is moving along a definite path of certain length.

Forms of energy



Main article: Units of energy

List of common units for energy. Official or common symbol in brackets after name and exact or approximate value of unit in joule in brackets after description.

SI unit

Other metric units

Imperial or US Customary units

Other units

Related units and concepts

Energy industry

Energy industry

Energy infrastructure

See especially Category:Electric power and Category:Fuels for a large number of conventional energy related topics.

Energy applications

History of energy

History of energy

Physics of energy

Allegorical and esoteric


Energy issues

Energy policies and use – national and international


Regional and national

Main page: Energy policy by country


Energy economics

Energy companies

Non-profit organizations

Industry associations



See also


  1. ^ "Retrieved on 2010-Dec-05". Archived from the original on 2007-12-13. Retrieved 2010-12-12.
  2. ^ "Retrieved on 2010-Dec-05" (PDF). Archived (PDF) from the original on 2011-04-26. Retrieved 2010-12-12.
  3. ^ Jain, Mahesh C. (2009). "Fundamental forces and laws: a brief review". Textbook Of Engineering Physics, Part 1. PHI Learning Pvt. Ltd. p. 10. ISBN 9788120338623.
  4. ^ McCall, Robert P. (2010). "Energy, Work and Metabolism". Physics of the Human Body. JHU Press. p. 74. ISBN 978-0-8018-9455-8.