The Energy Portal
Welcome to Wikipedia's energy portal, your gateway to the subject of energy and its effects on the world around us. This portal is aimed at educating you about energy and all its uses.
Energy is a set of physics measures. Popularly the term is most often used in the context of energy as a technology: energy resources, their consumption, development, depletion, and conservation. Biologically, bodies rely on food for energy in the same sense as industry relies on fuels to continue functioning. Since economic activities such as manufacturing and transportation can be energy intensive, energy efficiency, energy dependence, energy security and price are key concerns. Increased awareness of the effects of global warming has led to global debate and action for the reduction of greenhouse gases emissions; like many previous energy use patterns, it is changing not due to depletion or supply constraints but due to problems with waste, extraction, or geopolitical scenarios.
In the context of natural science, energy can take several different forms: thermal, chemical, electrical, radiant, nuclear, etc. These are often grouped as being either kinetic energy or potential energy. Many of these forms can be readily transformed into another with the help of a device - from chemical energy to electrical energy using a battery, for example. Most energy available for human use ultimately comes from the sun, which generates it with nuclear fusion. The enormous potential for fusion and other basic nuclear reactions is expressed by the famous equation E = mc2.
The concepts of energy and its transformations are useful in explaining natural processes on larger scales: Meteorological phenomena like wind, rain, lightning and tornadoes all result from energy transformations brought about by solar energy on the planet. Life itself is critically dependent on biological energy transformations; organic chemical bonds are constantly broken and made to make the exchange and transformation of energy possible. Read more...
produced by hydropower
. Hydroelectricity now supplies about 715,000 MWe
or 19% of world electricity (16% in 2003). It is also the world's leading form of renewable energy
, accounting for over 63% of the total in 2005. Although large hydroelectric installations generate most of the world's hydroelectricity, small hydro
schemes are particularly popular in China
Most hydroelectric power comes from the potential energy of dammed water driving a water turbine and generator. The energy extracted from water depends on the volume and on the difference in height between the source and the water's outflow. Pumped storage hydroelectricity schemes produce electricity to supply high peak demands by moving water between reservoirs at different elevations. They currently provide the only commercially important means of grid energy storage. At times of low electrical demand, excess generation capacity is used to pump water back into the higher reservoir, from where it can be released through the turbines at short notice. Less common types of hydroelectricity include run-of-the-river, waterwheels, and tidal power schemes.
A major advantage of hydroelectricity is the elimination of fuel costs and the associated carbon emissions although, in tropical regions, decaying plant material behind the dam can sometimes result in greater greenhouse gas emissions than a conventional power station. Other issues include the need to relocate people from areas to be flooded and disruption caused to aquatic ecosystems. Read more...
- Saudi Aramco is the largest oil corporation in the world and the world's largest in terms of proven crude oil reserves and production?
James Clerk Maxwell
(13 June 1831 – 5 November 1879) was a Scottish mathematician and theoretical physicist
. His most significant achievement was formulating a set of equations – eponymously
named Maxwell's equations
– that for the first time expressed the basic laws of electricity
in a unified fashion. Maxwell's contributions to physics
are considered by many to be of the same magnitude as those of Isaac Newton
and Albert Einstein
Maxwell studied natural philosophy, moral philosophy, and mental philosophy at the University of Edinburgh, before graduating in mathematics at the University of Cambridge, where he would conduct much of his career. He built on Michael Faraday's work on magnetic induction, using elements of geometry and algebra to demonstrate that electric and magnetic fields travel through space, in the form of waves, and at the constant speed of light. Finally, in 1861, Maxwell proposed that light consisted of undulations in the same medium that is the cause of electric and magnetic phenomena. In the same year he was elected to the Royal Society.
In 1864, Maxwell presented what are now known as Maxwell's equations to the Royal Society. These collectively describe the behaviour of both the electric and magnetic fields, as well as their interactions with matter. Read more...
WikiProjects connected with energy:
- WikiProject Energy
- Oil megaprojects task force
Other WikiProjects that may be of interest:
- WikiProject Environment
- WikiProject Technology
- WikiProject Biography
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