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...)
Selected article
Though technology exists to allow ethanol FFVs to run on any mixture of gasoline and ethanol, from pure gasoline up to 100% ethanol (E100), North American and European flex-fuel vehicles are optimized to run on a maximum blend of 15% gasoline with 85% anhydrous ethanol (called E85 fuel). This limit in the ethanol content is set to reduce ethanol emissions at low temperatures and to avoid cold starting problems during cold weather, at temperatures lower than 11 °C (52 °F). The alcohol content is reduced during the winter in regions where temperatures fall below 0 °C (32 °F) to a winter blend of E70 in the U.S. or to E75 in Sweden from November until March. Brazilian flex fuel vehicles are optimized to run on any mix of E20-E25 gasoline and up to 100% hydrous ethanol fuel (E100).
Selected image
Photo credit: Andreas Tille
Geysers erupt periodically due to surface water being heated by geothermal heat.
Did you know?
- Buildings constructed to the German Passivhaus standard use 75% to 95% less energy for space heating and cooling than current new buildings in the United States?
- Crossing 4,000 km (2,500 miles), the Druzhba pipeline is the world's longest oil pipeline?
- Coal is ground to a powder before being burnt in fossil fuel power plants?
- Compact fluorescent lamps (pictured) use about 1/4 of the energy of normal incandescent light bulbs, and pay for themselves after about 500 hours of use?
- Nuclear power in France produces 78% of all the country's electricity - more than in any other nation?
- Positive lightning bolts are typically six to ten times more powerful than normal lightning — and aircraft are not designed to withstand them?
- Dark energy is a hypothetical form of energy which permeates all of space?
Selected biography
In recognition of Watt's achievements, the SI unit of power, the watt, is named after him.
James Watt was born on 19th of January, 1736 in Greenock, a seaport on the Firth of Clyde. His father was a shipwright, shipowner and contractor, while his mother, Agnes Muirhead, came from a distinguished family and was well-educated. Both were Presbyterians and strong Covenanters. Watt attended school irregularly and instead was mostly schooled at home by his mother.
After studying instrument-making for a year in London, the University of Glasgow offered him the opportunity to set up a small workshop within the university. It was established in 1757. After four years, Watt began to experiment with steam, finally producing a working model steam engine in 1765. Strapped for resources to develop a full-scale engine, Watt was forced to take up employment as a surveyor for eight years. Finally, in 1776, the first engines were installed and working in commercial enterprises.
After further improvements, Watt and foundry owner Matthew Boulton established Boulton and Watt in 1794 to exclusively manufacture steam engines. By 1824 it had produced 1,164 steam engines having a total nominal horsepower of about 26,000.
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Quotations
- "If we already have the Kyoto protocol, why invent another proposal and not just implement one that already exists? If a country is incapable of implementing the result of an international treaty that has established rules and regulations, it won't end up implementing those rules voluntarily."" – Luiz Inácio Lula da Silva, 2007
- "Climate change is a challenge China must cope with to realize sustainable development... Implementing a climate change containment policy may cost a fortune, but the cost will be even higher if we delay. Early action is imperative." – Ma Kai, 2007
- "The consequences of restricting the development of developing nations will be much more serious than the consequences of global warming." – Ma Kai, 2007
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