Power station
Power plants (power stations)
Power Generation Equipment
Last Updated: October 7, 2015
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What is Power Plant? How do power plants work? How do we make electricity? What is a Megawatt and a Megawatt-Hour? What Is the meaning of 210 MW unit of a power plant? What is the difference between electricity generation capacity and electricity generation? How does energy get from a power plant to your home? Types of Power Plants |
| A power plant may have one or more generators, and some generators may use more than one type of fuel. |
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The Grand Coulee Dam in Washington State has a Nameplate capacity of 6,809 MW (megaWatts), the biggest in America. In 2014, the following ten power plants produced the most electricity in America: Palo Verde Nuclear Station 32,846,202,000 kWhs Browns Ferry Nuclear Station 26,738,300,000 kWhs Oconee Nuclear Generating Station 21,193,381,000 kWhs South Texas Project Nuclear Station 20,651,667,000 kWhs Grand Coulee Hydroelectric Station 20,266,322,000 kWhs Braidwood Nuclear Station 20,263,665,000 kWhs West County Energy Center (NGCC) 19,764,922,000 kWhs Byron Nuclear Generating Station 19,252,381,000 kWhs Limerick Nuclear Generating Station 19,077,244,000 kWhs Scherer Coal-fired Power Plant 18,894,546,000 kWhs |
List of largest power stations in the world
| Rank | Station | Location | Capacity (MW) | Annual generation (TWh) | Type |
| 1 | Three Gorges Dam | 30°49'15?N 111°00'08?E | 22,500 | 98.8 (2014) | Hydro |
| 2 | Itaipu Dam | 25°24'31?S 54°35'21?W | 14,000 | 98.63 (2013) | Hydro |
| 3 | Xiluodu | 28°15'52?N 103°38'47?E | 13,860 | 57.1 (estimated) | Hydro |
| 4 | Guri | 07°45'59?N 62°59'57?W | 10,200 | 47 (average) | Hydro |
| 5 | Tucuruí | 03°49'53?S 49°38'36?W | 8,370 | 21.4 (1999) | Hydro |
| 6 | Kashiwazaki-Kariwa | 37°25'45?N 138°35'43?E | 7,965 | 60.3 (1999) | Nuclear |
| 7 | Grand Coulee | 47°57'23?N 118°58'56?W | 6,809 | 21 (2008) | Hydro |
| 8 | Longtan | 25°01'38?N 107°02'51?E | 6,426 | 21 18.7 | 21 Hydro |
| 9 | Sayano-Shushenskaya | 54°49'33?N 91°22'13?E | 6,400 | 23.5 | Hydro |
| 10 | Bruce | 44°19'31?N 81°35'58?W | 6,300 | 45 (2013) | Nuclear |
| 11 | Krasnoyarsk | 55°56'05?N 92°17'40?E | 6,000 | 23.0 (2014) | Hydro |
| 12 | Hanul | 37°05'34?N 129°23'01?E | 5,881 | 48.16 | Nuclear |
| 13 | Hanbit | 35°24'54?N 126°25'26?E | 5,875 | 47.62 | Nuclear |
| 14 | Zaporizhia | 47°30'44?N 34°35'09?E | 5,700 | 48.16 (average) | Nuclear |
| 15 | Robert-Bourassa | 53°47'43?N 77°26'26?W | 5,616W | 26.5W | Hydro |
| 16 | Shoaiba | 20°40'48?N 39°31'24?E | 5,600 | ? (average) | Fuel oil |
| 17 | Surgut-2 | 61°16'46?N 73°30'45?E | 5,597 | 39.85 (2013) | Natural gas |
| 18 | Taichung | 24°12'46?N 120°28'52?E | 5,500 | 42 (average) | Coal |
| 19 | Gravelines | 24°12'46?N 120°28'52?E | 5,460 | 38.5 (average) | Nuclear |
| 20 | Churchill Falls | 53°31'43?N 63°57'57?W | 5,428 | 35 | Hydro |
Cardinal direction  A compass rose showing the four cardinal directions, the four intercardinal directions, plus eight further divisions. How to Determine Directions to North, South, East, and West |
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What is a Megawatt and a Megawatt-Hour? A megawatt is a unit for measuring power that is equivalent to one million watts. One megawatt is equivalent to the energy produced by 10 automobile engines. A megawatt hour (Mwh) is equal to 1,000 Kilowatt hours (Kwh). It is equal to 1,000 kilowatts of electricity used continuously for one hour. It is about equivalent to the amount of electricity used by about 330 homes during one hour. Most power stations contain one or more generators, a rotating machine that converts mechanical power into electrical power. The relative motion between a magnetic field and a conductor creates an electrical current. The energy source harnessed to turn the generator varies widely. Fossil-fuel power stations Hydroelectric power station Nuclear power plants Solar Wind Marine Osmosis Biomass What Is the meaning of 210 MW unit of a power plant? In other words what does it means of 210 or 250 or 600 MW power plant? MW stands for megawatt, which is a unit of power. A 210 MW power plant is capable of producing up to 210 MW of power, on an ongoing basis. In simple terms, that's how much power you expect the plant to be able to generate at any given time. This is generally the design rating: how much it's designed to handle under normal conditions. Plants can generally be operated below their design limit (though there's a limit to how low). There are also margins of safety in the design. It's usually possible for plants to operate at higher power than their design, but that would risk damaging equipment and possibly create safety hazards, so they're usually prohibited from doing so. What is the difference between electricity generation capacity and electricity generation? Capacity is the maximum electric output a generator can produce under specific conditions. Nameplate capacity is determined by the generator's manufacturer and indicates the maximum output a generator can produce without exceeding design thermal limits. Net summer capacity and net winter capacity are typically determined by a performance test and indicate the maximum load a generator can support at the point of interconnection during the respective season. There are two primary factors that affect or determine the difference in capacity between summer and winter months: • The temperature of cooling water for thermal power plants or the temperature of the ambient air for combustion turbines • The water flow and reservoir storage characteristics for hydropower plants Generation is the amount of electricity a generator produces over a specific period of time. For example, a generator with 1 megawatt (MW) capacity that operates at that capacity consistently for one hour will produce 1 megawatthour (mWh) of electricity. If it operates at only half that capacity for one hour, it will produce 0.5 mWh of electricity. Many generators do not operate at their full capacity all the time; they may vary their output according to conditions at the power plant, fuel costs, and/or as instructed from the electric power grid operator. Net generation is the amount of gross generation a generator produces less the electricity used to operate the power plant. These uses include fuel handling, feedwater pumps, combustion air fans, cooling water pumps, pollution control equipment, and other electricity needs. How does energy get from a power plant to your home? A power station is really a machine that extracts energy from a fuel. Some power stations burn fossil fuels such as coal, oil, or gas. Nuclear power stations produce energy by splitting apart atoms of heavy materials such as uranium and plutonium. The heat produced is used to convert water into steam at high pressure. This steam turns a windmill-like device called a turbine connected to an electricity generator. Extracting heat from a fuel takes place over a number of stages and some energy is wasted at each stage. That means power plants are not very efficient: in a typical plant running on coal, oil, or gas, only about 30–40 percent of the energy locked inside the fuel is converted to electricity and the rest is wasted. Artwork showing the steps involved in how a power plant makes electricity 1.Fuel: The energy that finds its way into your TV, computer, or toaster starts off as fuel loaded into a power plant. Some power plants run on coal, while others use oil, natural gas, or methane gas from decomposing rubbish. 2.Furnace: The fuel is burned in a giant furnace to release heat energy. 3.Boiler: In the boiler, heat from the furnace flows around pipes full of cold water. The heat boils the water and turns it into steam. 4.Turbine: The steam flows at high-pressure around a wheel that's a bit like a windmill made of tightly packed metal blades. The blades start turning as the steam flows past. Known as a steam turbine, this device is designed to convert the steam's energy into kinetic energy (the energy of something moving). For the turbine to work efficiently, heat must enter it at a really high temperature and pressure and leave at as low a temperature and pressure as possible. 5.Cooling tower: The giant, jug-shaped cooling towers you see at old power plants make the turbine more efficient. Boiling hot water from the steam turbine is cooled in a heat exchanger called a condenser. Then it's sprayed into the giant cooling towers and pumped back for reuse. Most of the water condenses on the walls of the towers and drips back down again. Only a small amount of the water used escapes as steam from the towers themselves, but huge amounts of heat and energy are lost. 6.Generator: The turbine is linked by an axle to a generator, so the generator spins around with the turbine blades. As it spins, the generator uses the kinetic energy from the turbine to make electricity. 7.Electricity cables: The electricity travels out of the generator to a transformer nearby. Left: Power plant transformers. Right: Power plant pylon transmission lines 8.Step-up transformer: Electricity loses some of its energy as it travels down wire cables, but high-voltage electricity loses less energy than low-voltage electricity. So the electricity generated in the plant is stepped-up (boosted) to a very high voltage as it leaves the power plant. 9.Pylons: Hugh metal towers carry electricity at extremely high voltages, along overhead cables, to wherever it is needed. 10.Step-down transformer: Once the electricity reaches its destination, another transformer converts the electricity back to a lower voltage safe for homes to use. 11.Homes: Electricity flows into homes through underground cables. 12.Appliances: Electricity flows all round your home to outlets on the wall. When you plug in a television or other appliance, it could be making a very indirect connection to a piece of coal hundreds of miles away! Types of Power Plants Hydro Power Plants – these plants use the kinetic energy of flowing water to rotate the turbine blades, hence converting kinetic energy into electrical energy. These types of power plants are very good for peak loads. Their main disadvantage lies in the fact that their location depends on a number of factors which are beyond the control of human beings such as the hydrological cycle of the region and so forth. If there is shortage of water it could lead to shut down of these plants. For this reason alternative arrangements such as thermal power plants need to be made to ensure uninterrupted generation of power. Six Important Components of Hydroelectric Power Hydroelectric Dam Water Reservoir Intake or Control Gates The Penstock Water Turbines Generators Generators It is in the generator where the electricity is produced. The shaft of the water turbine rotates in the generator, which produces alternating current in the coils of the generator. It is the rotation of the shaft inside the generator that produces magnetic field which is converted into electricity by electromagnetic field induction. Hence the rotation of the shaft of the turbine is crucial for the production of electricity and this is achieved by the kinetic and potential energy of water. Thus in hydroelectricity power plants potential energy of water is converted into electricity. Thermal Power Plants – as the name suggests, these power plants convert heat energy into electrical energy. The working fluid of these plants is mostly steam and they work on the Rankine cycle. A steam power plant consists of a boiler which is used to generate the steam from water, a prime mover like a steam turbine to convert the enthalpy of the steam into rotary motion of the turbine which is linked to the alternator to produce electricity. The steam is again condensed in the condenser and fed to the boiler again. Types of Nuclear Power Plants Pressurized Water Reactors Boiling Water Reactors Here are further guidelines. |