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120-473: The plant employs a proprietary concentrating solar power (CSP) trough technology developed by Abengoa , and covers an area of 1,920 acres (780 ha). Construction was expected to create about 1,500 construction jobs with the plant employing 85 full-time workers. Solar thermal plants use substantially more water for cooling than other solar generating technologies. Nevertheless, the Sierra Club supported

240-505: A n i c a l {\displaystyle \eta _{\mathrm {mechanical} }} is at most the Carnot efficiency, which is determined by the temperature of the receiver T H {\displaystyle T_{H}} and the temperature of the heat rejection ("heat sink temperature") T 0 {\displaystyle T^{0}} , The real-world efficiencies of typical engines achieve 50% to at most 70% of

360-460: A n i c a l {\displaystyle \eta _{mechanical}} , using Carnot's principle . The mechanical energy is then converted into electrical energy by a generator. For a solar receiver with a mechanical converter ( e.g. , a turbine), the overall conversion efficiency can be defined as follows: where η o p t i c s {\displaystyle \eta _{\mathrm {optics} }} represents

480-542: A Diesel cycle , Rankine cycle , Brayton cycle , etc.). The most common cycle involves a working fluid (often water) heated and boiled under high pressure in a pressure vessel to produce high-pressure steam. This high pressure-steam is then directed to a turbine, where it rotates the turbine's blades. The rotating turbine is mechanically connected to an electric generator which converts rotary motion into electricity. Fuels such as natural gas or oil can also be burnt directly in gas turbines ( internal combustion ), skipping

600-568: A heat engine (usually a steam turbine ) connected to an electrical power generator or powers a thermochemical reaction. As of 2021, global installed capacity of concentrated solar power stood at 6.8 GW. As of 2023, the total was 8.1 GW, with the inclusion of three new CSP projects in construction in China and in Dubai in the UAE. The U.S.-based National Renewable Energy Laboratory (NREL), which maintains

720-451: A steam drum , and the furnace with its steam generating tubes and superheater coils. Necessary safety valves are located at suitable points to protect against excessive boiler pressure. The air and flue gas path equipment include: forced draft (FD) fan , air preheater (AP), boiler furnace, induced draft (ID) fan, fly ash collectors ( electrostatic precipitator or baghouse ), and the flue-gas stack . The boiler feed water used in

840-435: A vacuum of about −95 kPa (−28 inHg) relative to atmospheric pressure. The large decrease in volume that occurs when water vapor condenses to liquid creates the vacuum that generally increases the efficiency of the turbines. The limiting factor is the temperature of the cooling water and that, in turn, is limited by the prevailing average climatic conditions at the power station's location (it may be possible to lower

960-542: A Greek scientist, Dr. Ioannis Sakkas, curious about whether Archimedes could really have destroyed the Roman fleet in 212 BC, lined up nearly 60 Greek sailors, each holding an oblong mirror tipped to catch the sun's rays and direct them at a tar-covered plywood silhouette 49 m (160 ft) away. The ship caught fire after a few minutes; however, historians continue to doubt the Archimedes story. In 1866, Auguste Mouchout used

1080-445: A container that would diminish heat transfer. A parabolic trough consists of a linear parabolic reflector that concentrates light onto a receiver positioned along the reflector's focal line. The receiver is a tube positioned at the longitudinal focal line of the parabolic mirror and filled with a working fluid. The reflector follows the sun during the daylight hours by tracking along a single axis. A working fluid (e.g. molten salt )

1200-399: A dispatchable form of solar energy. As such, it is increasingly seen as competing with natural gas and PV with batteries for flexible, dispatchable power. CSP is used to produce electricity (sometimes called solar thermoelectricity, usually generated through steam ). Concentrated solar technology systems use mirrors or lenses with tracking systems to focus a large area of sunlight onto

1320-660: A gas turbine, in the form of hot exhaust gas, can be used to raise steam by passing this gas through a heat recovery steam generator (HRSG). The steam is then used to drive a steam turbine in a combined cycle plant that improves overall efficiency. Power stations burning coal, fuel oil , or natural gas are often called fossil fuel power stations . Some biomass -fueled thermal power stations have appeared also. Non-nuclear thermal power stations, particularly fossil-fueled plants, which do not use cogeneration are sometimes referred to as conventional power stations . Commercial electric utility power stations are usually constructed on

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1440-442: A gas turbine. The steam generating boiler has to produce steam at the high purity, pressure and temperature required for the steam turbine that drives the electrical generator. Geothermal plants do not need boilers because they use naturally occurring steam sources. Heat exchangers may be used where the geothermal steam is very corrosive or contains excessive suspended solids. A fossil fuel steam generator includes an economizer ,

1560-410: A generator on a common shaft. There is usually a high-pressure turbine at one end, followed by an intermediate-pressure turbine, and finally one, two, or three low-pressure turbines, and the shaft that connects to the generator. As steam moves through the system and loses pressure and thermal energy, it expands in volume, requiring increasing diameter and longer blades at each succeeding stage to extract

1680-486: A global database of CSP plants, counts 6.6 GW of operational capacity and another 1.5 GW under construction. As a thermal energy generating power station, CSP has more in common with thermal power stations such as coal, gas, or geothermal. A CSP plant can incorporate thermal energy storage , which stores energy either in the form of sensible heat or as latent heat (for example, using molten salt ), which enables these plants to continue supplying electricity whenever it

1800-480: A large scale and designed for continuous operation. Virtually all electric power stations use three-phase electrical generators to produce alternating current (AC) electric power at a frequency of 50 Hz or 60 Hz . Large companies or institutions may have their own power stations to supply heating or electricity to their facilities, especially if steam is created anyway for other purposes. Steam-driven power stations have been used to drive most ships in most of

1920-407: A location. Unlike solar PV plants, CSP with thermal energy storage can also be used economically around the clock to produce process steam, replacing polluting fossil fuels . CSP plants can also be integrated with solar PV for better synergy. CSP with thermal storage systems are also available using Brayton cycle generators with air instead of steam for generating electricity and/or steam round

2040-448: A mirror dish was built by Dr. R.H. Goddard , who was already well known for his research on liquid-fueled rockets and wrote an article in 1929 in which he asserted that all the previous obstacles had been addressed. Professor Giovanni Francia (1911–1980) designed and built the first concentrated-solar plant, which entered into operation in Sant'Ilario, near Genoa, Italy in 1968. This plant had

2160-687: A parabolic trough to produce steam for the first solar steam engine. The first patent for a solar collector was obtained by the Italian Alessandro Battaglia in Genoa, Italy, in 1886. Over the following years, invеntors such as John Ericsson and Frank Shuman developed concentrating solar-powered dеvices for irrigation, refrigеration, and locomоtion. In 1913 Shuman finished a 55 horsepower (41 kW) parabolic solar thermal energy station in Maadi, Egypt for irrigation. The first solar-power system using

2280-559: A set of tubes in the furnace. Here the steam picks up more energy from hot flue gases outside the tubing, and its temperature is now superheated above the saturation temperature. The superheated steam is then piped through the main steam lines to the valves before the high-pressure turbine. Nuclear-powered steam plants do not have such sections but produce steam at essentially saturated conditions. Experimental nuclear plants were equipped with fossil-fired superheaters in an attempt to improve overall plant operating cost. The condenser condenses

2400-879: A small area. The concentrated light is then used as heat or as a heat source for a conventional power plant (solar thermoelectricity). The solar concentrators used in CSP systems can often also be used to provide industrial process heating or cooling, such as in solar air conditioning . Concentrating technologies exist in four optical types, namely parabolic trough , dish , concentrating linear Fresnel reflector , and solar power tower . Parabolic trough and concentrating linear Fresnel reflectors are classified as linear focus collector types, while dish and solar tower are point focus types. Linear focus collectors achieve medium concentration factors (50 suns and over), and point focus collectors achieve high concentration factors (over 500 suns). Although simple, these solar concentrators are quite far from

2520-523: A specific type of large heat exchanger used in a pressurized water reactor (PWR) to thermally connect the primary (reactor plant) and secondary (steam plant) systems, which generates steam. In a boiling water reactor (BWR), no separate steam generator is used and water boils in the reactor core. In some industrial settings, there can also be steam-producing heat exchangers called heat recovery steam generators (HRSG) which utilize heat from some industrial process, most commonly utilizing hot exhaust from

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2640-423: A stationary stator and a spinning rotor , each containing miles of heavy copper conductor. There is generally no permanent magnet , thus preventing black starts . In operation it generates up to 21,000 amperes at 24,000 volts AC (504 MWe) as it spins at either 3,000 or 3,600 rpm , synchronized to the power grid . The rotor spins in a sealed chamber cooled with hydrogen gas, selected because it has

2760-406: A trip-out are avoided by flushing out such gases from the combustion zone before igniting the coal. The steam drum (as well as the superheater coils and headers) have air vents and drains needed for initial start up. Fossil fuel power stations often have a superheater section in the steam generating furnace. The steam passes through drying equipment inside the steam drum on to the superheater,

2880-478: A typical late 20th-century power station, superheated steam from the boiler is delivered through 14–16-inch-diameter (360–410 mm) piping at 2,400 psi (17 MPa; 160 atm) and 1,000 °F (540 °C) to the high-pressure turbine, where it falls in pressure to 600 psi (4.1 MPa; 41 atm) and to 600 °F (320 °C) in temperature through the stage. It exits via 24–26-inch-diameter (610–660 mm) cold reheat lines and passes back into

3000-429: Is also dosed with pH control agents such as ammonia or morpholine to keep the residual acidity low and thus non-corrosive. The boiler is a rectangular furnace about 50 feet (15 m) on a side and 130 feet (40 m) tall. Its walls are made of a web of high pressure steel tubes about 2.3 inches (58 mm) in diameter. Fuel such as pulverized coal is air-blown into the furnace through burners located at

3120-706: Is also notable in North Africa and the Middle East, as well as China and India. There is a notable trend towards developing countries and regions with high solar radiation with several large plants under construction in 2017. The global market was initially dominated by parabolic-trough plants, which accounted for 90% of CSP plants at one point. Since about 2010, central power tower CSP has been favored in new plants due to its higher temperature operation – up to 565 °C (1,049 °F) vs. trough's maximum of 400 °C (752 °F) – which promises greater efficiency. Among

3240-477: Is designed to provide six hours of energy storage. This allows the plant to generate about 38 percent of its rated capacity over the course of a year. Solana Generating Station's production is as follows, averaging 742 GW·h annual, yielding about 390 MW·h/acre. Maximum annual electricity production was projected at 900,000 MW·h (900 GW·h), as calculated using the project's and NREL specific capacity factors. In 2020, Solana Generating Station has averaged 82.4% of

3360-473: Is expensive and has seldom been implemented. Government regulations and international agreements are being enforced to reduce harmful emissions and promote cleaner power generation. Almost all coal-fired power stations , petroleum, nuclear , geothermal , solar thermal electric , and waste incineration plants , as well as all natural gas power stations are thermal. Natural gas is frequently burned in gas turbines as well as boilers . The waste heat from

3480-457: Is given by the Carnot efficiency , which represents a theoretical limit to the efficiency that can be achieved by any system, set by the laws of thermodynamics . Real-world systems do not achieve the Carnot efficiency. The conversion efficiency η {\displaystyle \eta } of the incident solar radiation into mechanical work depends on the thermal radiation properties of

3600-685: Is heated to 150–350 °C (302–662 °F) as it flows through the receiver and is then used as a heat source for a power generation system. Trough systems are the most developed CSP technology. The Solar Energy Generating Systems (SEGS) plants in California, some of the longest-running in the world until their 2021 closure; Acciona's Nevada Solar One near Boulder City, Nevada ; and Andasol , Europe's first commercial parabolic trough plant are representative, along with Plataforma Solar de Almería 's SSPS-DCS test facilities in Spain . The design encapsulates

3720-474: Is limited, and governed by the laws of thermodynamics . The Carnot efficiency dictates that higher efficiencies can be attained by increasing the temperature of the steam. Sub-critical pressure fossil fuel power stations can achieve 36–40% efficiency. Supercritical designs have efficiencies in the low to mid 40% range, with new "ultra critical" designs using pressures above 4,400 psi (30 MPa) and multiple stage reheat reaching 45–48% efficiency. Above

Solana Generating Station - Misplaced Pages Continue

3840-488: Is needed, day or night. This makes CSP a dispatchable form of solar. Dispatchable renewable energy is particularly valuable in places where there is already a high penetration of photovoltaics (PV), such as California , because demand for electric power peaks near sunset just as PV capacity ramps down (a phenomenon referred to as duck curve ). CSP is often compared to photovoltaic solar (PV) since they both use solar energy. While solar PV experienced huge growth during

3960-587: Is one of the few renewable electricity technologies that can generate fully dispatchable or even fully baseload power at very large scale. Therefore, it may have an important role to play in the decarbonization of power grids as a dispatchable electricity source to balance the intermittent renewables, such as wind power and PV. CSP in combination with Thermal Energy Storage (TES) is expected by some to become cheaper than PV with lithium batteries for storage durations above 4 hours per day, while NREL expects that by 2030 PV with 10-hour storage lithium batteries will cost

4080-399: Is pumped. Flat mirrors allow more reflective surface in the same amount of space than a parabolic reflector, thus capturing more of the available sunlight, and they are much cheaper than parabolic reflectors. Fresnel reflectors can be used in various size CSPs. Fresnel reflectors are sometimes regarded as a technology with a worse output than other methods. The cost efficiency of this model

4200-476: Is returned to the downcomers and the steam is passed through a series of steam separators and dryers that remove water droplets from the steam. The dry steam then flows into the superheater coils. The boiler furnace auxiliary equipment includes coal feed nozzles and igniter guns, soot blowers , water lancing, and observation ports (in the furnace walls) for observation of the furnace interior. Furnace explosions due to any accumulation of combustible gases after

4320-464: Is separated from the water inside a drum at the top of the furnace. The saturated steam is introduced into superheat pendant tubes that hang in the hottest part of the combustion gases as they exit the furnace. Here the steam is superheated to 1,000 °F (540 °C) to prepare it for the turbine. Plants that use gas turbines to heat the water for conversion into steam use boilers known as heat recovery steam generators (HRSG). The exhaust heat from

4440-456: Is sunlight and require up to four years to ramp-up to 100% operating level. Concentrating solar power Concentrated solar power ( CSP , also known as concentrating solar power , concentrated solar thermal ) systems generate solar power by using mirrors or lenses to concentrate a large area of sunlight into a receiver. Electricity is generated when the concentrated light is converted to heat ( solar thermal energy ), which drives

4560-465: Is the air-cooled condenser . The process is similar to that of a radiator and fan. Exhaust heat from the low-pressure section of a steam turbine runs through the condensing tubes, the tubes are usually finned and ambient air is pushed through the fins with the help of a large fan. The steam condenses to water to be reused in the water-steam cycle. Air-cooled condensers typically operate at a higher temperature than water-cooled versions. While saving water,

4680-419: Is used in a steam generator to produce steam to generate electricity by steam turbo generator as required. Thus solar energy which is available in daylight only is used to generate electricity round the clock on demand as a load following power plant or solar peaker plant. The thermal storage capacity is indicated in hours of power generation at nameplate capacity . Unlike solar PV or CSP without storage,

4800-438: Is what causes some to use this instead of others with higher output ratings. Some new models of Fresnel reflectors with Ray Tracing capabilities have begun to be tested and have initially proved to yield higher output than the standard version. A dish Stirling or dish engine system consists of a stand-alone parabolic reflector that concentrates light onto a receiver positioned at the reflector's focal point. The reflector tracks

4920-786: The Manhattan Elevated Railway . Each of seventeen units weighed about 500 tons and was rated 6000 kilowatts; a contemporary turbine set of similar rating would have weighed about 20% as much. The energy efficiency of a conventional thermal power station is defined as saleable energy produced as a percent of the heating value of the fuel consumed. A simple cycle gas turbine achieves energy conversion efficiencies from 20 to 35%. Typical coal-based power plants operating at steam pressures of 170 bar and 570 °C run at efficiency of 35 to 38%, with state-of-the-art fossil fuel plants at 46% efficiency. Combined-cycle systems can reach higher values. As with all heat engines, their efficiency

Solana Generating Station - Misplaced Pages Continue

5040-597: The Stefan–Boltzmann law yields: Simplifying these equations by considering perfect optics ( η O p t i c s {\displaystyle \eta _{\mathrm {Optics} }} = 1) and without considering the ultimate conversion step into electricity by a generator, collecting and reradiating areas equal and maximum absorptivity and emissivity ( α {\displaystyle \alpha } = 1, ϵ {\displaystyle \epsilon } = 1) then substituting in

5160-403: The critical point for water of 705 °F (374 °C) and 3,212 psi (22.15 MPa), there is no phase transition from water to steam, but only a gradual decrease in density . Currently most nuclear power stations must operate below the temperatures and pressures that coal-fired plants do, in order to provide more conservative safety margins within the systems that remove heat from

5280-761: The larger CSP projects are the Ivanpah Solar Power Facility (392 MW) in the United States, which uses solar power tower technology without thermal energy storage, and the Ouarzazate Solar Power Station in Morocco, which combines trough and tower technologies for a total of 510 MW with several hours of energy storage. On purely generation cost, bulk power from CSP today is much more expensive than solar PV or Wind power, however, PV and Wind power are intermittent sources . Comparing cost on

5400-552: The steam boiler is a means of transferring heat energy from the burning fuel to the mechanical energy of the spinning steam turbine . The total feed water consists of recirculated condensate water and purified makeup water . Because the metallic materials it contacts are subject to corrosion at high temperatures and pressures, the makeup water is highly purified before use. A system of water softeners and ion exchange demineralizes produces water so pure that it coincidentally becomes an electrical insulator , with conductivity in

5520-409: The vapor pressure of water is much less than atmospheric pressure, the condenser generally works under vacuum . Thus leaks of non-condensible air into the closed loop must be prevented. Typically the cooling water causes the steam to condense at a temperature of about 25 °C (77 °F) and that creates an absolute pressure in the condenser of about 2–7  kPa (0.59–2.07  inHg ), i.e.

5640-531: The 18th century, with notable improvements being made by James Watt . When the first commercially developed central electrical power stations were established in 1882 at Pearl Street Station in New York and Holborn Viaduct power station in London, reciprocating steam engines were used. The development of the steam turbine in 1884 provided larger and more efficient machine designs for central generating stations. By 1892

5760-418: The 2010s due to falling prices, solar CSP growth has been slow due to technical difficulties and high prices. In 2017, CSP represented less than 2% of worldwide installed capacity of solar electricity plants. However, CSP can more easily store energy during the night, making it more competitive with dispatchable generators and baseload plants. The DEWA project in Dubai, under construction in 2019, held

5880-606: The 2010s. With a learning rate estimated at around 20% cost reduction of every doubling in capacity, the costs were approaching the upper end of the fossil fuel cost range at the beginning of the 2020s, driven by support schemes in several countries, including Spain, the US, Morocco, South Africa, China, and the UAE: CSP deployment has slowed down considerably in OECD countries, as most of the above-mentioned markets have cancelled their support, but CSP

6000-743: The 20th century . Shipboard power stations usually directly couple the turbine to the ship's propellers through gearboxes. Power stations in such ships also provide steam to smaller turbines driving electric generators to supply electricity. Nuclear marine propulsion is, with few exceptions, used only in naval vessels. There have been many turbo-electric ships in which a steam-driven turbine drives an electric generator which powers an electric motor for propulsion . Cogeneration plants, often called combined heat and power (CHP) facilities, produce both electric power and heat for process heat or space heating, such as steam and hot water. The reciprocating steam engine has been used to produce mechanical power since

6120-472: The Carnot efficiency due to losses such as heat loss and windage in the moving parts. For a solar flux I {\displaystyle I} (e.g. I = 1000 W / m 2 {\displaystyle I=1000\,\mathrm {W/m^{2}} } ) concentrated C {\displaystyle C} times with an efficiency η O p t i c s {\displaystyle \eta _{Optics}} on

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6240-464: The Enclosed Trough design, states its technology can produce heat for Enhanced Oil Recovery (EOR) for about $ 5 per 290 kWh (1,000,000 BTU) in sunny regions, compared to between $ 10 and $ 12 for other conventional solar thermal technologies. A solar power tower consists of an array of dual-axis tracking reflectors ( heliostats ) that concentrate sunlight on a central receiver atop a tower;

6360-606: The Solana plant, because it was built on private land, and was projected to use "75 to 85 percent less water than the current agricultural use." Arizona Public Service (APS) has contracted to purchase 100% of the power output generated from Solana, to meet the Arizona Corporation Commission 's (ACC) mandate that the state's regulated utilities provide 15% of their electricity from renewable energy sources by 2025. APS will pay about 14 cents per kWh. The Solana plant

6480-698: The Sun along two axes. The working fluid in the receiver is heated to 250–700 °C (482–1,292 °F) and then used by a Stirling engine to generate power. Parabolic-dish systems provide high solar-to-electric efficiency (between 31% and 32%), and their modular nature provides scalability. The Stirling Energy Systems (SES), United Sun Systems (USS) and Science Applications International Corporation (SAIC) dishes at UNLV , and Australian National University 's Big Dish in Canberra , Australia are representative of this technology. A world record for solar to electric efficiency

6600-498: The United States are about 90 percent efficient in converting the energy of falling water into electricity while the efficiency of a wind turbine is limited by Betz's law , to about 59.3%, and actual wind turbines show lower efficiency. The direct cost of electric energy produced by a thermal power station is the result of cost of fuel, capital cost for the plant, operator labour, maintenance, and such factors as ash handling and disposal. Indirect social or environmental costs, such as

6720-486: The air in the air preheater for better economy. Secondary air is mixed with the coal/primary air flow in the burners. The induced draft fan assists the FD fan by drawing out combustible gases from the furnace, maintaining slightly below atmospheric pressure in the furnace to avoid leakage of combustion products from the boiler casing. A steam turbine generator consists of a series of steam turbines interconnected to each other and

6840-506: The architecture of today's power tower plants, with a solar receiver in the center of a field of solar collectors. The plant was able to produce 1 MW with superheated steam at 100 bar and 500 °C. The 10 MW Solar One power tower was developed in Southern California in 1981. Solar One was converted into Solar Two in 1995, implementing a new design with a molten salt mixture (60% sodium nitrate, 40% potassium nitrate) as

6960-400: The atmosphere, or once-through cooling (OTC) water from a river, lake or ocean. In the United States, about two-thirds of power plants use OTC systems, which often have significant adverse environmental impacts. The impacts include thermal pollution and killing large numbers of fish and other aquatic species at cooling water intakes . The heat absorbed by the circulating cooling water in

7080-433: The boiler, where the steam is reheated in special reheat pendant tubes back to 1,000 °F (540 °C). The hot reheat steam is conducted to the intermediate-pressure turbine, where it falls in both temperature and pressure and exits directly to the long-bladed low-pressure turbines and finally exits to the condenser. The generator, typically about 30 feet (9 m) long and 12 feet (3.7 m) in diameter, contains

7200-424: The clock. These CSP plants are equipped with gas turbines to generate electricity. These are also small in capacity (<0.4 MW), with flexibility to install in few acres' area. Waste heat from the power plant can also be used for process steam generation and HVAC needs. In case land availability is not a limitation, any number of these modules can be installed, up to 1000 MW with RAMS and cost advantages since

7320-443: The condenser tubes must also be removed to maintain the ability of the water to cool as it circulates. This is done by pumping the warm water from the condenser through either natural draft, forced draft or induced draft cooling towers (as seen in the adjacent image) that reduce the temperature of the water by evaporation, by about 11 to 17 °C (52 to 63 °F)—expelling waste heat to the atmosphere. The circulation flow rate of

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7440-519: The cooling water in a 500 MW unit is about 14.2 m /s (500 ft /s or 225,000 US gal/min) at full load. The condenser tubes are typically made stainless steel or other alloys to resist corrosion from either side. Nevertheless, they may become internally fouled during operation by bacteria or algae in the cooling water or by mineral scaling, all of which inhibit heat transfer and reduce thermodynamic efficiency . Many plants include an automatic cleaning system that circulates sponge rubber balls through

7560-413: The day, the average conversion efficiency achieved is not equal to these maximum efficiencies, and the net annual solar-to-electricity efficiencies are 7-20% for pilot power tower systems, and 12-25% for demonstration-scale Stirling dish systems. Conversion efficiencies are relevant only where real estate land costs are not low. The maximum conversion efficiency of any thermal to electrical energy system

7680-411: The economic value of environmental impacts, or environmental and health effects of the complete fuel cycle and plant decommissioning, are not usually assigned to generation costs for thermal stations in utility practice, but may form part of an environmental impact assessment. Those indirect costs belong to the broader concept of externalities . In the nuclear plant field, steam generator refers to

7800-496: The efficiency of conversion of heat energy into mechanical energy, and η g e n e r a t o r {\displaystyle \eta _{\mathrm {generator} }} the efficiency of converting the mechanical energy into electrical power. η r e c e i v e r {\displaystyle \eta _{\mathrm {receiver} }} is: The conversion efficiency η m e c h

7920-472: The efficiency of the cycle is reduced (resulting in more carbon dioxide per megawatt-hour of electricity). From the bottom of the condenser, powerful condensate pumps recycle the condensed steam (water) back to the water/steam cycle. Power station furnaces may have a reheater section containing tubes heated by hot flue gases outside the tubes. Exhaust steam from the high-pressure turbine is passed through these heated tubes to collect more energy before driving

8040-416: The electricity grid, gives a different conclusion. Developers are hoping that CSP with energy storage can be a cheaper alternative to PV with BESS . Research found that PV with BESS is competitive for short storage durations, while CSP with TES gains economic advantages for long storage periods. Tipping point lies at 2–10 hours depending on cost of the composing blocks: CSP, PV, TES and BESS. As early as 2011,

8160-409: The first equation gives Thermal power station A thermal power station , also known as a thermal power plant , is a type of power station in which the heat energy generated from various fuel sources (e.g., coal , natural gas , nuclear fuel , etc.) is converted to electrical energy . The heat from the source is converted into mechanical energy using a thermodynamic power cycle (such as

8280-421: The four corners, or along one wall, or two opposite walls, and it is ignited to rapidly burn, forming a large fireball at the center. The thermal radiation of the fireball heats the water that circulates through the boiler tubes near the boiler perimeter. The water circulation rate in the boiler is three to four times the throughput. As the water in the boiler circulates it absorbs heat and changes into steam. It

8400-413: The fraction of incident light concentrated onto the receiver, η r e c e i v e r {\displaystyle \eta _{\mathrm {receiver} }} the fraction of light incident on the receiver that is converted into heat energy, η m e c h a n i c a l {\displaystyle \eta _{\mathrm {mechanical} }}

8520-403: The gas turbines is used to make superheated steam that is then used in a conventional water-steam generation cycle, as described in the gas turbine combined-cycle plants section. The water enters the boiler through a section in the convection pass called the economizer . From the economizer it passes to the steam drum and from there it goes through downcomers to inlet headers at the bottom of

8640-551: The heating value of the fuel used. Different thermodynamic cycles have varying efficiencies, with the Rankine cycle generally being more efficient than the Otto or Diesel cycles. In the Rankine cycle, the low-pressure exhaust from the turbine enters a steam condenser where it is cooled to produce hot condensate which is recycled to the heating process to generate even more high pressure steam. The design of thermal power stations depends on

8760-611: The highest known heat transfer coefficient of any gas and for its low viscosity , which reduces windage losses. This system requires special handling during startup, with air in the chamber first displaced by carbon dioxide before filling with hydrogen. This ensures that a highly explosive hydrogen– oxygen environment is not created. The power grid frequency is 60 Hz across North America and 50 Hz in Europe , Oceania , Asia ( Korea and parts of Japan are notable exceptions), and parts of Africa . The desired frequency affects

8880-590: The intended energy source. In addition to fossil and nuclear fuel , some stations use geothermal power , solar energy , biofuels , and waste incineration . Certain thermal power stations are also designed to produce heat for industrial purposes, provide district heating , or desalinate water , in addition to generating electrical power. Emerging technologies such as supercritical and ultra-supercritical thermal power stations operate at higher temperatures and pressures for increased efficiency and reduced emissions. Cogeneration or CHP (Combined Heat and Power) technology,

9000-428: The intermediate and then low-pressure turbines. External fans are provided to give sufficient air for combustion. The Primary air fan takes air from the atmosphere and, first warms the air in the air preheater for better economy. Primary air then passes through the coal pulverizers, and carries the coal dust to the burners for injection into the furnace. The Secondary air fan takes air from the atmosphere and, first warms

9120-450: The local economy by creating jobs in construction, maintenance, and fuel extraction industries. On the other hand, burning of fossil fuels releases greenhouse gases (contributing to climate change) and air pollutants such as sulfur oxides and nitrogen oxides (leading to acid rain and respiratory diseases). Carbon capture and storage (CCS) technology can reduce the greenhouse gas emissions of fossil-fuel-based thermal power stations, however it

9240-417: The middle of this series of feedwater heaters, and before the second stage of pressurization, the condensate plus the makeup water flows through a deaerator that removes dissolved air from the water, further purifying and reducing its corrosiveness. The water may be dosed following this point with hydrazine , a chemical that removes the remaining oxygen in the water to below 5 parts per billion (ppb). It

9360-476: The most advanced CSP stations (with TES) against record lows of 1.32 cents per kWh for utility-scale PV (without BESS). This five-fold price difference has been maintained since 2018. Some PV-CSP plants in China have sought to operate profitably on the regional coal tariff of 5 US cents per kWh in 2021. Even though overall deployment of CSP remains limited in the early 2020s, the levelized cost of power from commercial scale plants has decreased significantly since

9480-513: The most representative demonstration plants. The Planta Solar 10 (PS10) in Sanlucar la Mayor , Spain, is the first commercial utility-scale solar power tower in the world. The 377 MW Ivanpah Solar Power Facility , located in the Mojave Desert , was the largest CSP facility in the world, and uses three power towers. Ivanpah generated only 0.652 TWh (63%) of its energy from solar means, and

9600-444: The nuclear fuel. This, in turn, limits their thermodynamic efficiency to 30–32%. Some advanced reactor designs being studied, such as the very-high-temperature reactor , Advanced Gas-cooled Reactor , and supercritical water reactor , would operate at temperatures and pressures similar to current coal plants, producing comparable thermodynamic efficiency. The energy of a thermal power station not utilized in power production must leave

9720-648: The other 0.388 TWh (37%) was generated by burning natural gas . Supercritical carbon dioxide can be used instead of steam as heat-transfer fluid for increased electricity production efficiency. However, because of the high temperatures in arid areas where solar power is usually located, it is impossible to cool down carbon dioxide below its critical temperature in the compressor inlet. Therefore, supercritical carbon dioxide blends with higher critical temperature are currently in development. Fresnel reflectors are made of many thin, flat mirror strips to concentrate sunlight onto tubes through which working fluid

9840-522: The per MW costs of these units are lower than those of larger size solar thermal stations. Centralized district heating round the clock is also feasible with concentrated solar thermal storage plants. An early plant operated in Sicily at Adrano . The US deployment of CSP plants started by 1984 with the SEGS plants. The last SEGS plant was completed in 1990. From 1991 to 2005, no CSP plants were built anywhere in

9960-630: The plant in the form of heat to the environment. This waste heat can go through a condenser and be disposed of with cooling water or in cooling towers . If the waste heat is instead used for district heating , it is called cogeneration . An important class of thermal power station is that associated with desalination facilities; these are typically found in desert countries with large supplies of natural gas , and in these plants freshwater production and electricity are equally important co-products. Other types of power stations are subject to different efficiency limitations. Most hydropower stations in

10080-498: The plant produced only 600,000 MWh in its first full year of operation, according to information from the Federal Energy Information Administration . In 2015, the output increased to 700,000 MWh. In the summer of 2017, a microburst "knocked out the plant that July." but notwithstanding that, generation reached 723,966 MWh. A CSP thermal power block is like that of a coal or gas-fired plant, except its fuel

10200-627: The plant violated air pollution standards, and in 2016, fined the plant $ 1.5 million for violations of air quality standards. According to the Phoenix New Times , "The plant’s parent company, a subsidiary of Abengoa called Atlantica Yield, downplayed the issues, and a company representative said that better times are likely ahead." According to government documents, the plant is expected to produce 900,000 MWh every year. This amount of electricity could power about 65,000 typical homes in Arizona. However,

10320-510: The power generation from solar thermal storage plants is dispatchable and self-sustainable , similar to coal/ gas-fired power plants , but without the pollution. CSP with thermal energy storage plants can also be used as cogeneration plants to supply both electricity and process steam round the clock. As of December 2018, CSP with thermal energy storage plants' generation costs have ranged between 5 c € / kWh and 7 c € / kWh, depending on good to medium solar radiation received at

10440-539: The presence or absence of other system losses; in addition to the conversion efficiency, the optical system which concentrates the sunlight will also add additional losses. Real-world systems claim a maximum conversion efficiency of 23-35% for "power tower" type systems, operating at temperatures from 250 to 565 °C, with the higher efficiency number assuming a combined cycle turbine. Dish Stirling systems, operating at temperatures of 550-750 °C, claim an efficiency of about 30%. Due to variation in sun incidence during

10560-447: The projected production value. Nearby photovoltaic power station Agua Caliente , covering a larger site area of 2400 acres, had a Loan Programs Office projected generation of only 559 GW·h (instead yielding an average real 727 GW·h production). The plant opened in 2014 and has experienced some problems since its opening. In the summer of 2017, the plant had two transformer fires. Maricopa County environmental officials questioned whether

10680-405: The range of 0.3–1.0 microsiemens per centimeter. The makeup water in a 500 MWe plant amounts to perhaps 120 US gallons per minute (7.6 L/s) to replace water drawn off from the boiler drums for water purity management, and to also offset the small losses from steam leaks in the system. The feed water cycle begins with condensate water being pumped out of the condenser after traveling through

10800-399: The rapid decline of the price of photovoltaic systems led to projections that CSP (without TES) would no longer be economically viable. As of 2020, the least expensive utility-scale concentrated solar power stations in the United States and worldwide were five times more expensive than utility-scale photovoltaic power stations , with a projected minimum price of 7 cents per kilowatt-hour for

10920-432: The receiver contains a heat-transfer fluid, which can consist of water-steam or molten salt . Optically a solar power tower is the same as a circular Fresnel reflector. The working fluid in the receiver is heated to 500–1000 °C (773–1,273 K or 932–1,832 °F) and then used as a heat source for a power generation or energy storage system. An advantage of the solar tower is the reflectors can be adjusted instead of

11040-405: The receiver working fluid and as a storage medium. The molten salt approach proved effective, and Solar Two operated successfully until it was decommissioned in 1999. The parabolic-trough technology of the nearby Solar Energy Generating Systems (SEGS), begun in 1984, was more workable. The 354 MW SEGS was the largest solar power plant in the world until 2014. No commercial concentrated solar

11160-507: The remaining energy. The entire rotating mass may be over 200 metric tons and 100 feet (30 m) long. It is so heavy that it must be kept turning slowly even when shut down (at 3 rpm ) so that the shaft will not bow even slightly and become unbalanced. This is so important that it is one of only six functions of blackout emergency power batteries on site. (The other five being emergency lighting , communication , station alarms, generator hydrogen seal system, and turbogenerator lube oil.) For

11280-412: The same as PV with 4-hour storage used to cost in 2020. Countries with no PV cell production capability and low labour cost may reduce substantially the local CSP/PV cost gap. The efficiency of a concentrating solar power system depends on the technology used to convert the solar power to electrical energy, the operating temperature of the receiver and the heat rejection, thermal losses in the system, and

11400-686: The simultaneous production of electricity and useful heat from the same fuel source, improves the overall efficiency by using waste heat for heating purposes. Older, less efficient thermal power stations are being decommissioned or adapted to use cleaner and renewable energy sources. Thermal power stations produce 70% of the world's electricity. They often provide reliable, stable, and continuous baseload power supply essential for economic growth. They ensure energy security by maintaining grid stability, especially in regions where they complement intermittent renewable energy sources dependent on weather conditions. The operation of thermal power stations contributes to

11520-421: The solar receiver and on the heat engine ( e.g. steam turbine). Solar irradiation is first converted into heat by the solar receiver with the efficiency η R e c e i v e r {\displaystyle \eta _{Receiver}} , and subsequently the heat is converted into mechanical energy by the heat engine with the efficiency η m e c h

11640-443: The solar thermal system within a greenhouse-like glasshouse. The glasshouse creates a protected environment to withstand the elements that can negatively impact reliability and efficiency of the solar thermal system. Lightweight curved solar-reflecting mirrors are suspended from the ceiling of the glasshouse by wires. A single-axis tracking system positions the mirrors to retrieve the optimal amount of sunlight. The mirrors concentrate

11760-460: The steam from the exhaust of the turbine into liquid to allow it to be pumped. If the condenser can be made cooler, the pressure of the exhaust steam is reduced and efficiency of the cycle increases. The surface condenser is a shell and tube heat exchanger in which cooling water is circulated through the tubes. The exhaust steam from the low-pressure turbine enters the shell, where it is cooled and converted to condensate (water) by flowing over

11880-410: The steam generation step. These plants can be of the open cycle or the more efficient combined cycle type. The majority of the world's thermal power stations are driven by steam turbines, gas turbines, or a combination of the two. The efficiency of a thermal power station is determined by how effectively it converts heat energy into electrical energy, specifically the ratio of saleable electricity to

12000-420: The steam turbines. The condensate flow rate at full load in a 500 MW plant is about 6,000 US gallons per minute (400 L/s). The water is usually pressurized in two stages, and typically flows through a series of six or seven intermediate feed water heaters, heated up at each point with steam extracted from an appropriate extraction connection on the turbines and gaining temperature at each stage. Typically, in

12120-423: The sunlight and focus it on a network of stationary steel pipes, also suspended from the glasshouse structure. Water is carried throughout the length of the pipe, which is boiled to generate steam when intense solar radiation is applied. Sheltering the mirrors from the wind allows them to achieve higher temperature rates and prevents dust from building up on the mirrors. GlassPoint Solar , the company that created

12240-499: The support scheme. Where not bound in other countries, the manufacturers have adopted up to 200 MW size for a single unit, with a cost soft point around 125 MW for a single unit. Due to the success of Solar Two, a commercial power plant, called Solar Tres Power Tower , was built in Spain in 2011, later renamed Gemasolar Thermosolar Plant. Gemasolar's results paved the way for further plants of its type. Ivanpah Solar Power Facility

12360-423: The system solar receiver with a collecting area A {\displaystyle A} and an absorptivity α {\displaystyle \alpha } : For simplicity's sake, one can assume that the losses are only radiative ones (a fair assumption for high temperatures), thus for a reradiating area A and an emissivity ϵ {\displaystyle \epsilon } applying

12480-433: The temperature beyond the turbine limits during winter, causing excessive condensation in the turbine). Plants operating in hot climates may have to reduce output if their source of condenser cooling water becomes warmer; unfortunately this usually coincides with periods of high electrical demand for air conditioning . The condenser generally uses either circulating cooling water from a cooling tower to reject waste heat to

12600-507: The theoretical maximum concentration. For example, the parabolic-trough concentration gives about 1 ⁄ 3 of the theoretical maximum for the design acceptance angle , that is, for the same overall tolerances for the system. Approaching the theoretical maximum may be achieved by using more elaborate concentrators based on nonimaging optics . Different types of concentrators produce different peak temperatures and correspondingly varying thermodynamic efficiencies due to differences in

12720-455: The tubes as shown in the adjacent diagram. Such condensers use steam ejectors or rotary motor -driven exhausts for continuous removal of air and gases from the steam side to maintain vacuum . For best efficiency, the temperature in the condenser must be kept as low as practical in order to achieve the lowest possible pressure in the condensing steam. Since the condenser temperature can almost always be kept significantly below 100 °C where

12840-452: The tubes to scrub them clean without the need to take the system off-line. The cooling water used to condense the steam in the condenser returns to its source without having been changed other than having been warmed. If the water returns to a local water body (rather than a circulating cooling tower), it is often tempered with cool 'raw' water to prevent thermal shock when discharged into that body of water. Another form of condensing system

12960-432: The turbine was considered a better alternative to reciprocating engines; turbines offered higher speeds, more compact machinery, and stable speed regulation allowing for parallel synchronous operation of generators on a common bus. After about 1905, turbines entirely replaced reciprocating engines in almost all large central power stations. The largest reciprocating engine-generator sets ever built were completed in 1901 for

13080-400: The water walls. From these headers the water rises through the water walls of the furnace where some of it is turned into steam and the mixture of water and steam then re-enters the steam drum. This process may be driven purely by natural circulation (because the water is the downcomers is denser than the water/steam mixture in the water walls) or assisted by pumps. In the steam drum, the water

13200-412: The way that they track the sun and focus light. New innovations in CSP technology are leading systems to become more and more cost-effective. In 2023, Australia’s national science agency CSIRO tested a CSP arrangement in which tiny ceramic particles fall through the beam of concentrated solar energy, the ceramic particles capable of storing a greater amount of heat than molten salt, while not requiring

13320-593: The whole tower. Power-tower development is less advanced than trough systems, but they offer higher efficiency and better energy storage capability. Beam down tower application is also feasible with heliostats to heat the working fluid. CSP with dual towers are also used to enhance the conversion efficiency by nearly 24%. The Solar Two in Daggett , California and the CESA-1 in Plataforma Solar de Almeria Almeria, Spain, are

13440-457: The world record for lowest CSP price in 2017 at US$ 73 per MWh for its 700 MW combined trough and tower project: 600 MW of trough, 100 MW of tower with 15 hours of thermal energy storage daily. Base-load CSP tariff in the extremely dry Atacama region of Chile reached below $ 50/MWh in 2017 auctions. A legend has it that Archimedes used a "burning glass" to concentrate sunlight on the invading Roman fleet and repel them from Syracuse . In 1973

13560-400: The world until it was sold to United Sun Systems . Subsequently, larger parts of the installation have been moved to China to satisfy part of the large energy demand. In a CSP plant that includes storage, the solar energy is first used to heat molten salt or synthetic oil, which is stored providing thermal/heat energy at high temperature in insulated tanks. Later the hot molten salt (or oil)

13680-435: The world. Global installed CSP-capacity increased nearly tenfold between 2004 and 2013 and grew at an average of 50 percent per year during the last five of those years, as the number of countries with installed CSP was growing. In 2013, worldwide installed capacity increased by 36% or nearly 0.9 gigawatt (GW) to more than 3.4 GW. The record for capacity installed was reached in 2014, corresponding to 925 MW; however, it

13800-411: Was constructed at the same time but without thermal storage, using natural gas to preheat water each morning. Most concentrated solar power plants use the parabolic trough design, instead of the power tower or Fresnel systems. There have also been variations of parabolic trough systems like the integrated solar combined cycle (ISCC) which combines troughs and conventional fossil fuel heat systems. CSP

13920-609: Was constructed from 1990, when SEGS was completed, until 2006, when the Compact linear Fresnel reflector system at Liddell Power Station in Australia was built. Few other plants were built with this design, although the 5 MW Kimberlina Solar Thermal Energy Plant opened in 2009. In 2007, 75 MW Nevada Solar One was built, a trough design and the first large plant since SEGS. Between 2010 and 2013, Spain built over 40 parabolic trough systems, size constrained at no more than 50 MW by

14040-415: Was followed by a decline caused by policy changes, the global financial crisis, and the rapid decrease in price of the photovoltaic cells. Nevertheless, total capacity reached 6800 MW in 2021. Spain accounted for almost one third of the world's capacity, at 2,300 MW, despite no new capacity entering commercial operation in the country since 2013. The United States follows with 1,740 MW. Interest

14160-468: Was originally planned to open in 2011 and was estimated to cost $ 2 billion. In December 2010, Abengoa received a $ 1.45 billion loan guarantee to support construction of the plant. One of the principal advantages of concentrated solar thermal (CST) is that thermal energy storage can be provided efficiently, so that output can be provided after the sun goes down, and output can be scheduled to meet demand requirements. The Solana Generating Station

14280-402: Was originally treated as a competitor to photovoltaics, and Ivanpah was built without energy storage, although Solar Two included several hours of thermal storage. By 2015, prices for photovoltaic plants had fallen and PV commercial power was selling for 1 ⁄ 3 of contemporary CSP contracts. However, increasingly, CSP was being bid with 3 to 12 hours of thermal energy storage, making CSP

14400-694: Was set at 31.25% by SES dishes at the National Solar Thermal Test Facility (NSTTF) in New Mexico on 31 January 2008, a cold, bright day. According to its developer, Ripasso Energy, a Swedish firm, in 2015 its dish Stirling system tested in the Kalahari Desert in South Africa showed 34% efficiency. The SES installation in Maricopa, Phoenix, was the largest Stirling Dish power installation in

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