View source for Category:Energy ← Category:Energy You do not have permission to edit this page, for the following reason: You are not allowed to execute the action you have requested. You can view and copy the source of this page. == Background == [[Image:0169 - Ames Generator.jpg|thumb|right|340px|[[Milestones:Ames Hydroelectric Generating Plant, 1891|Ames Hydroelectric Generating Plant]]]] Energy and powered devices are an integral part of society. Humanity's earliest days saw the discovery of fire through wood combustion, and the use of charcoal for smelting metals dates back as early as 5000 BC. Powered devices using natural energy sources such as water and wind were introduced by the Ancient Greeks and were commonly used until the 18th century steam engine revolutionized the way devices could be powered. Various natural oils were used for a range of purposes, such as whale oil for lamps. The Industrial Revolution led to the massive use of coal as fuel, and the extraction of petroleum and various other oils became extremely important with the advent of internal combustion engines. Electrical power, also based on fossil fuels, became widespread at the end of the 19th century and the production of cleaner electrical energy through nuclear, hydropower, geothermal, and solar means is a topic even more relevant to today's world. == Subcategories == *'''[[:Category:Alternative energy|Alternative energy]]''' - Energy sources considered to be alternatives to fossil fuel sources *'''[[:Category:Electric variables control|Electric variables control]]''' - Topics pertaining to control involving electric variables including current and gain control *'''[[:Category:Electrochemical devices & processes|Electrochemical devices & processes]]''' - Devices and processes which produce electricity from chemical reactions such as batteries, fuel cells and supercapacitors *'''[[:Category:Electromechanical systems|Electromechanical systems]]''' - Various mechnical systems which produce electricity such as belts, drives, and furnaces *'''[[:Category:Electrostatic devices & processes|Electrostatic devices & processes]]''' - Devices and processes dealing with static electricity including particle charging, surface charging and triboelectricity *'''[[:Category:Energy facilities design, construction and operation|Energy facilities design, construction and operation]]''' - Various topics related to all aspects of energy facilities *'''[[:Category:Engines|Engines]]''' - Machines which transform energy into physical motion *'''[[:Category:Fuels|Fuels]]''' - Topics related to materials used as energy sources *'''[[:Category:Nuclear and plasma sciences|Nuclear and plasma sciences]]''' - The study of atomic particles, including the state of plasma where a certain number of particles are ionized *'''[[:Category:Power electronics|Power electronics]]''' - The use of electronics for conversion of electric power *'''[[:Category:Power engineering|Power engineering]]''' - Engineering for power distribution and electrification *'''[[:Category:Power generation|Power generation]]''' - Topics and devices which are capable of generating power such as nuclear power generation, solar power generation and hydroelectric power generation *'''[[:Category:Power systems|Power systems]]''' - Various kinds of power systems such as hybrid power systems, industrial power systems and transformers *'''[[:Category:Production and well operations|Production and well operations]]''' - General topics related to well operations *'''[[:Category:Renewable energy|Renewable energy]]''' - Energy sources considered to be replenishable *'''[[:Category:Reservoirs|Reservoirs]]''' - Naturally occurring and artificial stores of fluid energy *'''[[:Category:Smart grid|Smart grid]]''' - Modernized electrical grids which attempts to automate efficiency controls for electrical power distribution *'''[[:Category:Solar energy|Solar energy]]''' - Energy derived from the sun *'''[[:Category:Well completion|Well completion]]''' - The process of preparing wells so they are ready for production *'''[[:Category:Well drilling|Well drilling]]''' - The process of drilling a hole in the earth for the purpose of extraction of materials Return to Category:Energy. Retrieved from "http://ethw.org/Category:Energy"