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Small Hydro
Small hydro is the development of hydroelectric power on a scale suitable for local community and industry, or to contribute to distributed generation in a regional electricity grid. Exact definitions vary, but a "small hydro" project is less than 50 megawatts (MW), and can be further subdivide by scale into "mini" (<1MW), "" (<100 kW), "" (<10 kW). In contrast many hydroelectric projects are of enormous size, such as the generating plant at the Three Gorges Dam at 22,500 megawatts or the vast multiple projects of the Tenn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fall In Licq-Atherey
Autumn, also known as fall in American English and Canadian English, is one of the four temperate seasons on Earth. Outside the tropics, autumn marks the transition from summer to winter, in September ( Northern Hemisphere) or March ( Southern Hemisphere). Autumn is the season when the duration of daylight becomes noticeably shorter and the temperature cools considerably. Day length decreases and night length increases as the season progresses until the Winter Solstice in December (Northern Hemisphere) and June (Southern Hemisphere). One of its main features in temperate climates is the striking change in colour for the leaves of deciduous trees as they prepare to shed. Date definitions Some cultures regard the autumnal equinox as "mid-autumn", while others with a longer temperature lag treat the equinox as the start of autumn. In the English-speaking world of high latitude countries, autumn traditionally began with Lammas Day and ended around Hallowe'en, the approxima ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
China Village Electrification Program
The China Village Electrification Program (''Song Dian Dao Cun'') was a scheme to provide renewable electricity to 3.5 million households in 10,000 villages by 2010. This was to be followed by full rural electrification using renewable energy by 2015.Renewables Global Status Report 2006 Update , '' REN21'', published 2006, accessed 2007-05-16 
The total program was expected to cost in the region of US$5 billion, and [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Irrigation District
In the United States an irrigation district is a cooperative, self-governing public corporation set up as a subdivision of the State government, with definite geographic boundaries, organized, and having taxing power to obtain and distribute water for irrigation of lands within the district; created under the authority of a State legislature with the consent of a designated fraction of the landowners or citizens. It is a special-purpose district created by statute in order to develop large irrigation projects. These districts have the power to tax, borrow, and condemn. Sample districts See also *Deficit irrigation *''Huerta'' *Irrigation District Act of 1916 (Smith Act) *Irrigation Districts and Farm Loans Act Sponsored by Democratic Party Congressional representative for California John E. Raker, the Irrigation Districts and Farm Loans Act, also known as the Raker Act, required that a court of competent jurisdiction confirm contracts between the Secr ... * Water district ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acequia
An acequia () or séquia () is a community-operated watercourse used in Spain and former Spanish colonies in the Americas for irrigation. Particularly in Spain, the Andes, northern Mexico, and the modern-day American Southwest particularly northern New Mexico and southern Colorado, acequias are usually historically engineered canals that carry snow runoff or river water to distant fields. Examples of acequias in New Mexico have lengthy historical roots to Pueblo and Hispano communities, and they are incorporated into traditions including the matachines, life in the Rio Grande Bosque of the Albuquerque metropolitan area, and pilgrimages to El Santuario de Chimayo. The term can also refer to the long central pool in a Moorish garden, such as the Generalife in the Alhambra in Southern Iberia. Overview The Spanish word (and Catalan ) comes from Classical Arabic , which has the double meaning of 'the water conduit' or 'one that bears water' and the 'barmaid' (from , ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Weir
A weir or low head dam is a barrier across the width of a river that alters the flow characteristics of water and usually results in a change in the height of the river level. Weirs are also used to control the flow of water for outlets of lakes, ponds, and reservoirs. There are many weir designs, but commonly water flows freely over the top of the weir crest before cascading down to a lower level. Etymology There is no single definition as to what constitutes a weir and one English dictionary simply defines a weir as a small dam, likely originating from Middle English ''were'', Old English ''wer'', derivative of root of ''werian,'' meaning "to defend, dam". Function Commonly, weirs are used to prevent flooding, measure water discharge, and help render rivers more navigable by boat. In some locations, the terms dam and weir are synonymous, but normally there is a clear distinction made between the structures. Usually, a dam is designed specifically to impound water beh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Induction Generator
An induction generator or ''asynchronous generator'' is a type of alternating current (AC) electrical generator that uses the principles of induction motors to produce electric power. Induction generators operate by mechanically turning their rotors faster than synchronous speed. A regular AC induction motor usually can be used as a generator, without any internal modifications. Because they can recover energy with relatively simple controls, induction generators are useful in applications such as mini hydro power plants, wind turbines, or in reducing high-pressure gas streams to lower pressure. An induction generator draws reactive excitation current from an external source. Induction generators have an AC rotor and cannot bootstrap using residual magnetization to black start a de-energized distribution system as synchronous machines do. Power factor correcting capacitors can be added externally to neutralize a constant amount of the variable reactive excitation current. After ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrical Generator
In electricity generation, a generator is a device that converts motive power (mechanical energy) or fuel-based power ( chemical energy) into electric power for use in an external circuit. Sources of mechanical energy include steam turbines, gas turbines, water turbines, internal combustion engines, wind turbines and even hand cranks. The first electromagnetic generator, the Faraday disk, was invented in 1831 by British scientist Michael Faraday. Generators provide nearly all of the power for electric power grids. In addition to electromechanical designs, photovoltaic and fuel cell powered generators utilize solar power and hydrogen-based fuels, respectively, to generate electrical output. The reverse conversion of electrical energy into mechanical energy is done by an electric motor, and motors and generators have many similarities. Many motors can be mechanically driven to generate electricity; frequently they make acceptable manual generators. Terminology Electromag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydro Turbine
A water turbine is a rotary machine that converts kinetic energy and potential energy of water into mechanical work. Water turbines were developed in the 19th century and were widely used for industrial power prior to electrical grids. Now, they are mostly used for electric power generation. Water turbines are mostly found in dams to generate electric power from water potential energy. History Water wheels have been used for hundreds of years for industrial power. Their main shortcoming is size, which limits the flow rate and head that can be harnessed. The migration from water wheels to modern turbines took about one hundred years. Development occurred during the Industrial revolution, using scientific principles and methods. They also made extensive use of new materials and manufacturing methods developed at the time. Swirl The word turbine was introduced by the French engineer Claude Burdin in the early 19th century and is derived from the Greek word "τύρβη" ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydraulic Head
Hydraulic head or piezometric head is a specific measurement of liquid pressure above a vertical datum., 410 pages. See pp. 43–44., 650 pages. See p. 22. It is usually measured as a liquid surface elevation, expressed in units of length, at the entrance (or bottom) of a piezometer. In an aquifer, it can be calculated from the depth to water in a piezometric well (a specialized water well), and given information of the piezometer's elevation and screen depth. Hydraulic head can similarly be measured in a column of water using a standpipe piezometer by measuring the height of the water surface in the tube relative to a common datum. The hydraulic head can be used to determine a ''hydraulic gradient'' between two or more points. "Head" in fluid dynamics In fluid dynamics, ''head'' is a concept that relates the energy in an incompressible fluid to the height of an equivalent static column of that fluid. From Bernoulli's principle, the total energy at a given point in a f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HKO Transmission 02
HKO may refer to: * '' Hello Kitty Online'', a video game * Helsinki Philharmonic Orchestra (Finnish: ) * Hong Kong Observatory The Hong Kong Observatory is a weather forecast agency of the government of Hong Kong. The Observatory forecasts the weather and issues warnings on weather-related hazards. It also monitors and makes assessments on radiation levels in ... * Hankou railway station, China Railway pinyin code HKO {{Disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Run-of-the-river Hydroelectricity
Run-of-river hydroelectricity (ROR) or run-of-the-river hydroelectricity is a type of hydroelectric generation plant whereby little or no water storage is provided. Run-of-the-river power plants may have no water storage at all or a limited amount of storage, in which case the storage reservoir is referred to as pondage. A plant without pondage is subject to seasonal river flows, thus the plant will operate as an intermittent energy source. Conventional hydro uses reservoirs, which regulate water for flood control, dispatchable electrical power, and the provision of fresh water for agriculture. Concept Run-of-the-river, or ROR, hydroelectricity is considered ideal for streams or rivers that can sustain a minimum flow or those regulated by a lake or reservoir upstream. A small dam is usually built to create a headpond ensuring that there is enough water entering the penstock pipes that lead to the turbines, which are at a lower elevation. Projects with pondage, as opposed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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