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
The defining feature of an internal combustion engine is that useful work is performed by the expanding hot gases acting directly to cause movement, for example by acting on pistons, rotors, or even by pressing on and moving the entire engine itself.
Internal combustion engines are most commonly used for mobile propulsion systems, where their high power-to-weight ratios, together with excellent fuel energy-density, are advantageous. They have appeared in almost all automobiles, motorbikes, many boats, and in a wide variety of aircraft and locomotives. Where very high power is required, such as jet aircraft, helicopters and large ships, they appear mostly in the form of gas turbines. They are also used for electric generators and by industry.
The most common fuels in use today are hydrocarbons derived from petroleum including diesel, gasoline and liquified petroleum gas. Most internal combustion engines designed for gasoline can run on natural gas or liquified petroleum gases without modifications except for the fuel delivery components. Liquid and gaseous biofuels, including ethanol and biodiesel can also be used, and trials of hydrogen fuel have been in progress for some years.
Selected image
Photo credit: Andreas Tille
Geysers erupt periodically due to surface water being heated by geothermal heat.
Did you know?
- The 1,222 km long Nordstream pipeline between Russia and the Germany is the world's longest underwater pipeline?
- Due to the vast quantity of coal burnt in fossil fuel power plants, they cause more radioactive contamination than nuclear power plants?
- Chinese energy policy includes using renewable energy for the rural electrification of 3.5 million households by 2010?
- The 354 MW SEGS solar power plant (pictured) in the Mojave Desert is the world's largest?
- Known reserves of petroleum are typically estimated at around 1.2 trillion barrels, or at 3.74 trillion barrels if oil sands are included?
- The concentration of the greenhouse gas carbon dioxide has increased from about 280 parts per million to about 380 ppm since the start of the Industrial Revolution. That's an increase of 35.71%. The estimated population of the world in 1750 was 791 Million people. The estimated population of the world on June 30th, 2007 was 6.6 Billion people. That's an increase of 734.39%.?
- In the 1990s Bougainville conflict, islanders cut off from oil supplies due to a blockade used coconut oil to fuel their vehicles?
- The Organization of the Petroleum Exporting Countries (OPEC) is considered a cartel by many observers?
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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National energy supply, use & conservation
National electricity sector
Politics, economics, environment
- Climate change
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Energy sources
- Fuels
- Biofuels
- Fossil fuels
- Fusion power
- Nuclear technology
- Renewable energy
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- Electric power
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