Portal:Energy
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The Energy Portal Welcome to Wikipedia's Energy portal, your gateway to energy. This portal is aimed at giving you access to all energy related topics in all of its forms.
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Introduction
In physics, energy (from Ancient Greek ἐνέργεια (enérgeia) 'activity') is the quantitative property that is transferred to a body or to a physical system, recognizable in the performance of work and in the form of heat and light. Energy is a conserved quantity—the law of conservation of energy states that energy can be converted in form, but not created or destroyed. The unit of measurement for energy in the International System of Units (SI) is the joule (J).
Common forms of energy include the kinetic energy of a moving object, the potential energy stored by an object (for instance due to its position in a field), the elastic energy stored in a solid object, chemical energy associated with chemical reactions, the radiant energy carried by electromagnetic radiation, and the internal energy contained within a thermodynamic system. All living organisms constantly take in and release energy.
Due to mass–energy equivalence, any object that has mass when stationary (called rest mass) also has an equivalent amount of energy whose form is called rest energy, and any additional energy (of any form) acquired by the object above that rest energy will increase the object's total mass just as it increases its total energy.
Human civilization requires energy to function, which it gets from energy resources such as fossil fuels, nuclear fuel, or renewable energy. The Earth's climate and ecosystems processes are driven by the energy the planet receives from the Sun (although a small amount is also contributed by geothermal energy). (Full article...)
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The remaining worldwide energy resources are large, with the remaining fossil fuels totaling an estimated 0.4 YJ (1 YJ = 1024 J) and the available nuclear fuel such as uranium exceeding 2.5 YJ (1 YJ = 1024 J). Mostly thanks to the Sun, the world also has a renewable usable energy flux that exceeds 120 PW (8,000 times 2004 total energy usage), or 3.8 YJ/yr, dwarfing all non-renewable resources.
Despite the abundance of fossil fuels there are a number of pressures that may move the world’s energy consumption to alternative energy sources. These include political considerations over energy security and potential pressure from energy superpowers, environmental concerns related to global warming and sustainability, and economic pressure resulting from energy price rises, carbon emissions trading and green taxation.
This move is already starting to happen in some countries, notably as a result of the Kyoto Protocol, and further steps in this direction are proposed. For example, the European Commission has proposed that the energy policy of the European Union should set a binding target of increasing the maximum level of renewable energy in the EU’s overall mix from less than 7% today to 20% by 2020.
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Photo credit: Björn Appel
A solar furnace can be used to generate electricity, melt steel or make hydrogen fuel.
Did you know?
- If atmospheric greenhouse gas concentrations can be stabilized at 450 ppm, it is thought that there will be a 50% chance of avoiding dangerous climate change?
- The Itaipu hydroelectric power plant is currently the second largest power plant in the world, supplying over 90% of Paraguay's electricity, and 25% of Brazil's?
- Libya's Sirte Basin—which in some places lies more than 47 metres below sea level—contains roughly 80% of the country's known crude oil reserves?
- Approximately 95% of the electricity consumed by a normal incandescent light bulb (example pictured) is emitted as heat, rather than as visible light?
- Saudi Aramco is the largest oil corporation in the world and the world's largest in terms of proven crude oil reserves and production?
- Newcastle, Australia, is the world's largest coal export port?
- Surplus income from oil production in Norway is invested by the Government Pension Fund, one of the World's largest funds with a value of around US$ 800 billion?
- Energy superpowers Russia and Venezuela have, respectively, the world's largest reserves of natural gas and petroleum?
Selected biography
Born in Ireland, Thomson studied at the University of Glasgow, Scotland. On graduating, he became a mathematics teacher at the Royal Belfast Academical Institution. During his life Thomson published more than 600 scientific papers and filed over 70 patents.
As early as 1845 Thomson pointed out that the experimental results of William Snow Harris were in accordance with the laws of Coulomb. Over the period 1855 to 1867, Thomson collaborated with Peter Guthrie Tait the Treatise on Natural Philosophy that unified the various branches of physical science under the common principle of energy. His inventions included the current balance for the precise specification of the ampere, the standard unit of electric current.
In 1893, Thomson headed an international commission to decide on the design of the Niagara Falls power station. Despite his previous belief in the superiority of direct current electric power transmission, he agreed to use alternating current after seeing a Westinghouse demonstration at the Chicago World's Fair.
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Quotations
- "We must not waste time and energy disputing the IPCC's report or debating the right machinery for making progress. The International Panel's work should be taken as our sign post: and the United Nations Environment Programme and the World Meteorological Organisation as the principal vehicles for reaching our destination." – Margaret Thatcher, 1990
- "The Kyoto treaty would have wrecked our economy, if I can be blunt." – George W. Bush, 2005
- "We strongly believe that the efforts needed to combat climate change do not have to be regarded as constraints on the economy. Instead, they can be used as a lever for new, green technology." – Maud Olofsson, 2007
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