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102-568: The SOLAR Project consists of the Solar One , Solar Two and Solar Tres solar thermal power plants based in the Mojave Desert , United States and Andalucía, Spain. The US Department of Energy (DOE) and a consortium of US utilities built the country's first two large-scale, demonstration solar power towers in the desert near Barstow, California. Solar One/Solar Two have been scrapped since 2009. Solar Tres (later renamed Gemasolar),

204-438: A "great observatory" for gamma-ray astronomy. The Compton Gamma Ray Observatory (CGRO) was designed to take advantage of the major advances in detector technology during the 1980s, and was launched in 1991. The satellite carried four major instruments which have greatly improved the spatial and temporal resolution of gamma-ray observations. The CGRO provided large amounts of data which are being used to improve our understanding of

306-533: A 1300 m (14,000 sq. ft.) collector in Coimbatore, India used for drying marigolds. A food processing facility in Modesto, California uses parabolic troughs to produce steam used in the manufacturing process. The 5,000 m collector area is expected to provide 15 TJ per year. These collectors could be used to produce approximately 50% and more of the hot water needed for residential and commercial use in

408-456: A 24-hour period. Since peak electricity demand typically occurs between about 4 and 8 pm, many CSP power plants use 3 to 5 hours of thermal storage. With current technology, storage of heat is much cheaper and more efficient than storage of electricity. In this way, the CSP plant can produce electricity day and night. If the CSP site has predictable solar radiation, then the CSP plant becomes

510-459: A background would be expected from the interaction of cosmic rays (very energetic charged particles in space) with interstellar gas. The first true astrophysical gamma-ray sources were solar flares, which revealed the strong 2.223 MeV line predicted by Morrison. This line results from the formation of deuterium via the union of a neutron and proton; in a solar flare the neutrons appear as secondaries from interactions of high-energy ions accelerated in

612-436: A combined cycle with natural gas. The enclosed trough architecture encapsulates 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 within the glasshouse structure. A single-axis tracking system positions

714-472: A cooking container. The most common reflector geometries are flat plate, disc and parabolic trough type. These designs cook faster and at higher temperatures (up to 350 °C; 660 °F) but require direct light to function properly. The Solar Kitchen in Auroville , India uses a unique concentrating technology known as the solar bowl . Contrary to conventional tracking reflector/fixed receiver systems,

816-502: A higher energy range than space-based observatories, since their effective areas can be many orders of magnitude larger than a satellite. In April 2018, the largest catalog yet of high-energy gamma-ray sources in space was published. In a 18 May 2021 press release, China's Large High Altitude Air Shower Observatory (LHAASO) reported the detection of a dozen ultra-high-energy gamma rays with energies exceeding 1 peta-electron-volt (quadrillion electron-volts or PeV), including one at 1.4 PeV,

918-497: A next-generation gamma ray observatory which will incorporate many of these improvements and will be ten times more sensitive, is planned to be fully operational by 2025. Long before experiments could detect gamma rays emitted by cosmic sources, scientists had known that the universe should be producing them. Work by Eugene Feenberg and Henry Primakoff in 1948, Sachio Hayakawa and I.B. Hutchinson in 1952, and, especially, Philip Morrison in 1958 had led scientists to believe that

1020-425: A number of different processes which were occurring in the universe would result in gamma-ray emission. These processes included cosmic ray interactions with interstellar gas , supernova explosions, and interactions of energetic electrons with magnetic fields . However, it was not until the 1960s that our ability to actually detect these emissions came to pass. Most gamma rays coming from space are absorbed by

1122-406: A painted perforated metal solar heat absorber that also serves as the exterior wall surface of the building. Heat transfer to the air takes place on the surface of the absorber, through the metal absorber and behind the absorber. The boundary layer of solar heated air is drawn into a nearby perforation before the heat can escape by convection to the outside air. The heated air is then drawn from behind

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1224-404: A point 2.4 billion light-years from earth. The gamma-ray burst occurred as some giant stars exploded at the ends of their lives before collapsing into black holes, in the direction of the constellation Sagitta . It has been estimated that the burst released up to 18 teraelectronvolts of energy, or even a possible TeV of 251. It seemed that GRB221009A was a long gamma-ray burst, possibly triggered by

1326-515: A refrigeration device. In the United States, heating , ventilation , and air conditioning ( HVAC ) systems account for over 25% (4.75 EJ) of the energy used in commercial buildings (50% in northern cities) and nearly half (10.1 EJ) of the energy used in residential buildings. Solar heating, cooling, and ventilation technologies can be used to offset a portion of this energy. The most popular solar heating technology for heating buildings

1428-425: A reliable power plant. Reliability can further be improved by installing a back-up combustion system. The back-up system can use most of the CSP plant, which decreases the cost of the back-up system. With reliability, unused desert, no pollution, and no fuel costs, the obstacles for large deployment for CSP are cost, aesthetics, land use and similar factors for the necessary connecting high tension lines. Although only

1530-482: A small percentage of the desert is necessary to meet global electricity demand, still a large area must be covered with mirrors or lenses to obtain a significant amount of energy. An important way to decrease cost is the use of a simple design. When considering land use impacts associated with the exploration and extraction through to transportation and conversion of fossil fuels , which are used for most of our electrical power, utility-scale solar power compares as one of

1632-601: A solar collector with a cooling engine making ice cream at the 1878 Universal Exhibition in Paris . The first installation of solar thermal energy equipment occurred in the Sahara approximately in 1910 by Frank Shuman when a steam engine was run on steam produced by sunlight. Because liquid fuel engines were developed and found more convenient, the Sahara project was abandoned, only to be revisited several decades later. As of 2023,

1734-489: A total observation time of 6 hours. The supernova SN1987A in the Large Magellanic Cloud (LMC) was discovered on February 23, 1987, and its progenitor, Sanduleak -69 202 , was a blue supergiant with luminosity of 2-5 × 10 erg/s. The 847 keV and 1238 keV gamma-ray lines from Co decay have been detected. During its High Energy Astronomy Observatory program in 1977, NASA announced plans to build

1836-534: A total of 3.2 million acres. Currently, 38.2 million acres of onshore public lands and an additional 36.9 million acres of offshore exploration in the Gulf of Mexico are under lease for oil and gas development, exploration and production. During the day the sun has different positions. For low concentration systems (and low temperatures) tracking can be avoided (or limited to a few positions per year) if nonimaging optics are used. For higher concentrations, however, if

1938-475: Is Nevada Solar One plant with a capacity of 64 MW. The 150 MW Andasol solar power stations are in Spain with each site having a capacity of 50 MW. Note however, that those plants have heat storage which requires a larger field of solar collectors relative to the size of the steam turbine-generator to store heat and send heat to the steam turbine at the same time. Heat storage enables better utilization of

2040-459: Is a subfield of astronomy where scientists observe and study celestial objects and phenomena in outer space which emit cosmic electromagnetic radiation in the form of gamma rays , i.e. photons with the highest energies (above 100 keV ) at the very shortest wavelengths. Radiation below 100 keV is classified as X-rays and is the subject of X-ray astronomy . In most cases, gamma rays from solar flares and Earth's atmosphere fall in

2142-545: Is an explosion in a solar atmosphere and was originally detected visually in the Sun . Solar flares create massive amounts of radiation across the full electromagnetic spectrum from the longest wavelength, radio waves , to high energy gamma rays. The correlations of the high energy electrons energized during the flare and the gamma rays are mostly caused by nuclear combinations of high energy protons and other heavier ions. These gamma rays can be observed and allow scientists to determine

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2244-596: Is capable of storing heat for months at a time, so solar heat collected primarily in Summer can be used for all-year heating. Solar-supplied STES technology has been advanced primarily in Denmark, Germany, and Canada, and applications include individual buildings and district heating networks. Drake Landing Solar Community in Alberta, Canada has a small district system and in 2012 achieved a world record of providing 97% of

2346-601: Is even detected, and because gamma rays are difficult to focus, resulting in a very low resolution. The most recent generation of gamma-ray telescopes (2000s) have a resolution of the order of 6 arc minutes in the GeV range (seeing the Crab Nebula as a single "pixel"), compared to 0.5 arc seconds seen in the low energy X-ray (1 keV) range by the Chandra X-ray Observatory (1999), and about 1.5 arc minutes in

2448-632: Is more popular in the USA and Canada than heating with solar liquid collectors since most buildings already have a ventilation system for heating and cooling. The two main types of solar air panels are glazed and unglazed. Of the 21,000,000 square feet (2,000,000 m ) of solar thermal collectors produced in the United States in 2007, 16,000,000 square feet (1,500,000 m ) were of the low-temperature variety. Low-temperature collectors are generally installed to heat swimming pools, although they can also be used for space heating. Collectors can use air or water as

2550-586: Is not common. Solar distillation is necessary in these situations to provide people with purified water. Solar energy heats up the water in the still. The water then evaporates and condenses on the bottom of the covering glass. Dr Lin Zhao of MIT published a peer-reviewed academic journal in Joule detailing their design for a solar autoclave for the sterilisation of surgical instruments without electricity. A prototype, which incorporates inexpensive aerogel

2652-467: Is one of the oldest applications of solar energy. Modern uses include concentrating brine solutions used in leach mining and removing dissolved solids from waste streams. Altogether, evaporation ponds represent one of the largest commercial applications of solar energy in use today. Unglazed transpired collectors are perforated sun-facing walls used for preheating ventilation air. Transpired collectors can also be roof mounted for year-round use and can raise

2754-444: Is sometimes illuminated by the reflected sunbeams to create an unusual atmospheric phenomenon in the vicinity of the power tower. These beams of light were depicted in several scenes, and a painting, in the 1987 movie Bagdad Cafe , which was filmed nearby. Nevada Solar One shares a similar name to Solar One, however it is quite different. It uses a solar thermal parabolic trough system and generates 64 MW. In 1995 Solar One

2856-500: Is that the heated water can be stored until it is needed, eliminating the need for a separate energy storage system. Solar thermal power can also be converted to electricity by using the steam generated from the heated water to drive a turbine connected to a generator. However, because generating electricity this way is much more expensive than photovoltaic power plants, there are very few in use today. Augustin Mouchot demonstrated

2958-787: Is the building integrated transpired solar air collection system which connects to the building's HVAC equipment. According to Solar Energy Industries Association over 500,000 m (5,000,000 square feet) of these panels are in operation in North America as of 2015. In Europe, since the mid-1990s about 125 large solar-thermal district heating plants have been constructed, each with over 500 m (5400 ft ) of solar collectors. The largest are about 10,000 m (2½ acres), with capacities of 7 MW-thermal and solar heat costs around 4 Eurocents/kWh without subsidies. 40 of them have nominal capacities of 1 MW-thermal or more. The Solar District Heating program (SDH) has participation from 14 European Nations and

3060-402: Is the most obvious application, but solar cooling can be achieved for a building or for district cooling by using a heat-driven absorption or adsorption chiller (heat pump). There is a productive coincidence that the greater the driving heat from insolation, the greater the cooling output. In 1878, Auguste Mouchout pioneered solar cooling by making ice using a solar steam engine attached to

3162-426: Is three times larger than Solar Two with 2,493 heliostats, each with a reflective surface of 96 m. The total reflective area will be 240,000 m (2.6 million ft). They will be made of a highly reflective glass with metal back to cut costs by about 45%. A larger molten nitrate salt storage tank will be used giving the plant the ability to store 600 MWh, allowing the plant to run 24/7 during

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3264-546: Is to reduce the plant's collector size and total land use per unit power generated, reducing the environmental impacts of a power plant as well as its expense. As the temperature increases, different forms of conversion become practical. Up to 600 °C (1100 °F), steam turbines , standard technology, have an efficiency up to 41%. Above 600 °C (1100 °F), gas turbines can be more efficient. Higher temperatures are problematic because different materials and techniques are needed. One proposal for very high temperatures

3366-609: Is to use liquid fluoride salts operating between 700 °C (1300 °F) to 800 °C (1500 °F) , using multi-stage turbine systems to achieve 50% or more thermal efficiencies. The higher operating temperatures permit the plant to use higher-temperature dry heat exchangers for its thermal exhaust, reducing the plant's water use – critical in the deserts where large solar plants are practical. High temperatures also make heat storage more efficient, because more watt-hours are stored per unit of fluid. Commercial concentrating solar thermal power (CSP) plants were first developed in

3468-484: Is uncovered during the day allowing sunlight to warm the water bladder and store heat for evening use. When cooling is a concern the covered bladder draws heat from the building's interior during the day and is uncovered at night to radiate heat to the cooler atmosphere. The Skytherm house in Atascadero, California uses a prototype roof pond for heating and cooling. Solar space heating with solar air heat collectors

3570-542: The High Energy Stereoscopic System (H.E.S.S.), which explores extreme astrophysical environments like the vicinity of black holes in active galactic nuclei . Studying gamma rays provides valuable insights into extreme astrophysical environments, as observed by the H.E.S.S. Observatory. Ongoing research aims to expand our understanding of gamma-ray sources, such as blazars, and their implications for cosmology. As GeV gamma rays are important in

3672-536: The Solar Two tower was demolished. The mothballed site was levelled and returned to vacant land by Southern California Edison. All heliostats and other hardware were removed. Due to the success of Solar Two, a commercial power plant, originally called Solar Tres Power Tower, now known as Gemasolar Thermosolar Plant built in Spain by Torresol Energy using Solar One and Solar Two's technology for commercial electrical production of 15 MW. Solar Tres

3774-596: The United States . It is called the Solar Energy Generating Systems (SEGS) system. Other CSP designs lack this kind of long experience and therefore it can currently be said that the parabolic trough design is the most thoroughly proven CSP technology. The SEGS is a collection of nine plants with a total capacity of 354 MW and has been the world's largest solar power plant, both thermal and non-thermal, for many years. A newer plant

3876-725: The 1970s, satellite observatories found several gamma-ray sources, among which a very strong source called Geminga was later identified as a pulsar in proximity. The Compton Gamma Ray Observatory (launched in 1991) revealed numerous gamma-ray sources in space. Today, both ground-based observatories like the VERITAS array and space-based telescopes like the Fermi Gamma-ray Space Telescope (launched in 2008) contribute significantly to gamma-ray astronomy. This interdisciplinary field involves collaboration among physicists, astrophysicists, and engineers in projects like

3978-431: The 1980s. The world’s largest solar thermal power plants are now the 370 MW Ivanpah Solar Power Facility , commissioned in 2014, and the 354 MW SEGS CSP installation, both located in the Mojave Desert of California, where several other solar projects have been realized as well. The principal advantage of CSP is the ability to efficiently add thermal storage, allowing the dispatching of electricity over up to

4080-594: The Earth's atmosphere, so gamma-ray astronomy could not develop until it was possible to get detectors above all or most of the atmosphere using balloons and spacecraft. The first gamma-ray telescope carried into orbit, on the Explorer 11 satellite in 1961, picked up fewer than 100 cosmic gamma-ray photons. They appeared to come from all directions in the Universe, implying some sort of uniform "gamma-ray background". Such

4182-572: The Earth’s atmosphere, necessitating balloon-borne detectors and artificial satellites in space. Early experiments in the 1950s and 1960s used balloons to carry instruments to access altitudes where the atmospheric absorption of gamma rays is low, followed by the launch of the first gamma-ray satellites: SAS 2 (1972) and COS-B (1975). These were defense satellites originally designed to detect gamma rays from secret nuclear testing, but they luckily discovered puzzling gamma-ray bursts coming from deep space. In

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4284-480: The European Commission, and is working toward technical and market development, and holds annual conferences. Glazed solar collectors are designed primarily for space heating. They recirculate building air through a solar air panel where the air is heated and then directed back into the building. These solar space heating systems require at least two penetrations into the building and only perform when

4386-662: The Fermi team released its second catalog of gamma-ray sources detected by the satellite's Large Area Telescope (LAT), which produced an inventory of 1,873 objects shining with the highest-energy form of light. 57% of the sources are blazars . Over half of the sources are active galaxies , their central black holes created gamma-ray emissions detected by the LAT. One third of the sources have not been detected in other wavelengths. Ground-based gamma-ray observatories include HAWC , MAGIC , HESS , and VERITAS . Ground-based observatories probe

4488-575: The MeV range, but it's now known that solar flares can also produce gamma rays in the GeV range, contrary to previous beliefs. Much of the detected gamma radiation stems from collisions between hydrogen gas and cosmic rays within our galaxy . These gamma rays, originating from diverse mechanisms such as electron-positron annihilation , the inverse Compton effect and in some cases gamma decay , occur in regions of extreme temperature, density, and magnetic fields, reflecting violent astrophysical processes like

4590-453: The Trombe wall radiates stored heat. Solar roof ponds for solar heating and cooling were developed by Harold Hay in the 1960s. A basic system consists of a roof-mounted water bladder with a movable insulating cover. This system can control heat exchange between interior and exterior environments by covering and uncovering the bladder between night and day. When heating is a concern the bladder

4692-772: The US reduces a households' operating costs by $ 6 per person per month. Solar water heating can reduce CO 2 emissions of a family of four by 1 ton/year (if replacing natural gas) or 3 ton/year (if replacing electricity). Medium-temperature installations can use any of several designs: common designs are pressurized glycol, drain back, batch systems and newer low pressure freeze tolerant systems using polymer pipes containing water with photovoltaic pumping. European and International standards are being reviewed to accommodate innovations in design and operation of medium temperature collectors. Operational innovations include "permanently wetted collector" operation. This innovation reduces or even eliminates

4794-664: The USA. Modern Cherenkov telescope experiments like H.E.S.S. , VERITAS , MAGIC , and CANGAROO III can detect the Crab Nebula in a few minutes. The most energetic photons (up to 16 TeV ) observed from an extragalactic object originate from the blazar , Markarian 501 (Mrk 501). These measurements were done by the High-Energy-Gamma-Ray Astronomy ( HEGRA ) air Cherenkov telescopes. Gamma-ray astronomy observations are still limited by non-gamma-ray backgrounds at lower energies, and, at higher energy, by

4896-514: The United States. In the United States, a typical system costs $ 4000–$ 6000 retail ($ 1400 to $ 2200 wholesale for the materials) and 30% of the system qualifies for a federal tax credit + additional state credit exists in about half of the states. Labor for a simple open loop system in southern climates can take 3–5 hours for the installation and 4–6 hours in Northern areas. Northern system require more collector area and more complex plumbing to protect

4998-409: The absorber plate into the building's ventilation system. A Trombe wall is a passive solar heating and ventilation system consisting of an air channel sandwiched between a window and a sun-facing thermal mass. During the ventilation cycle, sunlight stores heat in the thermal mass and warms the air channel causing circulation through vents at the top and bottom of the wall. During the heating cycle

5100-478: The air in the solar collector is warmer than the building room temperature. Most glazed collectors are used in the residential sector. Unglazed solar collectors are primarily used to pre-heat make-up ventilation air in commercial, industrial and institutional buildings with a high ventilation load. They turn building walls or sections of walls into low cost, high performance, unglazed solar collectors. Also called, "transpired solar panels" or " solar wall ", they employ

5202-697: The atmosphere that can be observed on the ground, both directly by radiation counters and optically via the Cherenkov light which the ultra-relativistic shower particles emit. The Imaging Atmospheric Cherenkov Telescope technique currently achieves the highest sensitivity. Gamma radiation in the TeV range emanating from the Crab Nebula was first detected in 1989 by the Fred Lawrence Whipple Observatory at Mt. Hopkins , in Arizona in

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5304-415: The collector from freezing. With this incentive, the payback time for a typical household is four to nine years, depending on the state. Similar subsidies exist in parts of Europe. A crew of one solar plumber and two assistants with minimal training can install a system per day. Thermosiphon installation have negligible maintenance costs (costs rise if antifreeze and mains power are used for circulation) and in

5406-775: The community's all-year space heating needs from the sun. STES thermal storage mediums include deep aquifers; native rock surrounding clusters of small-diameter, heat exchanger equipped boreholes; large, shallow, lined pits that are filled with gravel and top-insulated; and large, insulated and buried surface water tanks. Centralized district heating round the clock is also feasible with concentrated solar thermal (CST) storage plant. Interseasonal storage. Solar heat (or heat from other sources) can be effectively stored between opposing seasons in aquifers , underground geological strata, large specially constructed pits, and large tanks that are insulated and covered with earth. Short-term storage. Thermal mass materials store solar energy during

5508-488: The day and release this energy during cooler periods. Common thermal mass materials include stone, concrete, and water. The proportion and placement of thermal mass should consider several factors such as climate, daylighting, and shading conditions. When properly incorporated, thermal mass can passively maintain comfortable temperatures while reducing energy consumption. Worldwide, by 2011 there were about 750 cooling systems with solar-driven heat pumps, and annual market growth

5610-573: The decay of neutral pions . They provide insights into extreme events like supernovae , hypernovae , and the behavior of matter in environments such as pulsars and blazars . A huge number of gamma ray emitting high-energy systems like black holes , stellar coronas , neutron stars , white dwarf stars, remnants of supernova, clusters of galaxies, including the Crab Nebula and the Vela pulsar (the most powerful source so far), have been identified, alongside an overall diffuse gamma-ray background along

5712-423: The direct solar radiation onto a glass tube containing a fluid (also called a receiver, absorber or collector) running the length of the trough, positioned at the focal point of the reflectors. The trough is parabolic along one axis and linear in the orthogonal axis. For change of the daily position of the sun perpendicular to the receiver, the trough tilts east to west so that the direct radiation remains focused on

5814-611: The ease of cooking and are able to reach temperatures of 450-650 °C (850 °F to 1200 °F). Built in 1999 by the Brahma Kumaris , the world's largest Scheffler reflector system in Abu Road, Rajasthan India is capable of cooking up to 35,000 meals a day. By early 2008, over 2000 large cookers of the Scheffler design had been built worldwide. Solar stills can be used to make drinking water in areas where clean water

5916-478: The energy to be stored in large tanks for future use such as night time—Solar Two had sufficient capacity to continue running for up to three hours after the sun had set. Solar Two was decommissioned in 1999. In 2001, the University of California, Davis, received funding to convert it into an air Cherenkov telescope for measuring gamma rays hitting the atmosphere . The first astronomical observations were in

6018-479: The explosions of massive stars ( supernovas and hypernovas ) in distant galaxies. As of 2021, Swift remains operational. Currently the (other) main space-based gamma-ray observatories are INTEGRAL (International Gamma-Ray Astrophysics Laboratory), Fermi , and AGILE (Astro-rivelatore Gamma a Immagini Leggero). In November 2010, using the Fermi Gamma-ray Space Telescope , two gigantic gamma-ray bubbles, spanning about 25,000 light-years across, were detected at

6120-557: The extraction of meaningful insights from vast datasets, leading to discoveries of new gamma-ray sources, identification of specific gamma-ray signatures, and improved modeling of gamma-ray emission mechanisms. Future missions may include space telescopes and lunar gamma-ray observatories (taking advantage of the Moon 's lack of atmosphere and stable environment for prolonged observations), enabling observations in previously inaccessible regions. The ground-based Cherenkov Telescope Array project,

6222-635: The fall of 2004, and the last were in November 2005 This project was named C.A.C.T.U.S. The facility was operated by the University of California, Davis but owned by Southern California Edison . Solar Two's three primary participants were Southern California Edison (SCE), the Los Angeles Department of Water and Power (LADWP), and the U.S. Department of Energy (DOE). On November 25, 2009, after 10 years of not producing any energy,

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6324-534: The field of gamma-ray astronomy took great leaps forward with the SAS-2 (1972) and the Cos-B (1975–1982) satellites. These two satellites provided an exciting view into the high-energy universe (sometimes called the 'violent' universe, because the kinds of events in space that produce gamma rays tend to be high-speed collisions and similar processes). They confirmed the earlier findings of the gamma-ray background, produced

6426-593: The first commercial plant of the project, was opened in Spain in 2011. Solar One was a pilot solar-thermal project built in the Mojave Desert just east of Barstow , CA , USA. It was the first test of a large-scale thermal solar power tower plant. Solar One was designed by the Department of Energy (DOE) (led by Sandia National Laboratories in Livermore, California ), Southern California Edison, LA Dept of Water and Power, and California Energy Commission. It

6528-555: The first detailed map of the sky at gamma-ray wavelengths, and detected a number of point sources. However the resolution of the instruments was insufficient to identify most of these point sources with specific visible stars or stellar systems. A discovery in gamma-ray astronomy came in the late 1960s and early 1970s from a constellation of military defense satellites. Detectors on board the Vela satellite series, designed to detect flashes of gamma rays from nuclear bomb blasts, began to record bursts of gamma rays from deep space rather than

6630-550: The flare process. These first gamma-ray line observations were from OSO 3 , OSO 7 , and the Solar Maximum Mission , the latter spacecraft launched in 1980. The solar observations inspired theoretical work by Reuven Ramaty and others. Significant gamma-ray emission from our galaxy was first detected in 1967 by the detector aboard the OSO 3 satellite. It detected 621 events attributable to cosmic gamma rays. However,

6732-532: The heart of the Milky Way . These bubbles of high-energy radiation are suspected as erupting from a massive black hole or evidence of a burst of star formations from millions of years ago. They were discovered after scientists filtered out the "fog of background gamma-rays suffusing the sky". This discovery confirmed previous clues that a large unknown "structure" was in the center of the Milky Way. In 2011

6834-419: The heat collected is used for electric power generation. CST and CSP are not replaceable in terms of application. Unlike photovoltaic cells that convert sunlight directly into electricity, solar thermal systems convert it into heat. They use mirrors or lenses to concentrate sunlight onto a receiver, which in turn heats a water reservoir. The heated water can then be used in homes. The advantage of solar thermal

6936-430: The heat transfer fluid is stagnant. Such temperatures are too low for efficient conversion to electricity. The efficiency of heat engines increases with the temperature of the heat source. To achieve this in solar thermal energy plants, solar radiation is concentrated by mirrors or lenses to obtain higher temperatures – a technique called Concentrated Solar Power (CSP). The practical effect of high efficiencies

7038-555: The heat. High-temperature heat transfer fluid was used to carry the energy to a boiler on the ground where the steam was used to spin a series of turbines, much like a traditional power plant. In the late 1970s, a competition was held by the DoE to obtain the best heliostat design for the project. Several promising designs were selected and prototypes were built and shipped to the area for testing. Trade-offs involved simplicity of construction to minimize costs for high-volume manufacturing versus

7140-430: The high energy X-ray (100 keV) range seen by High-Energy Focusing Telescope (2005). Very energetic gamma rays, with photon energies over ~30 GeV, can also be detected by ground-based experiments. The extremely low photon fluxes at such high energies require detector effective areas that are impractically large for current space-based instruments. Such high-energy photons produce extensive showers of secondary particles in

7242-571: The high-energy processes in our Universe. CGRO was de-orbited in June 2000 as a result of the failure of one of its stabilizing gyroscopes . BeppoSAX was launched in 1996 and deorbited in 2003. It predominantly studied X-rays, but also observed gamma-ray bursts. By identifying the first non-gamma ray counterparts to gamma-ray bursts, it opened the way for their precise position determination and optical observation of their fading remnants in distant galaxies. The High Energy Transient Explorer 2 (HETE-2)

7344-533: The highest energy photon ever observed. The authors of the report have named the sources of these PeV gamma rays PeVatrons. Astronomers using the Gemini South telescope located in Chile observed flash from a Gamma-Ray Burst identified as GRB221009A , on 14 October 2022. Gamma-ray bursts are the most energetic flashes of light known to occur in the universe. Scientists of NASA estimated that the burst occurred at

7446-558: The incoming air temperature up to 22 °C (72 °F) and deliver outlet temperatures of 45-60 °C (110° to 140 °F). The short payback period of transpired collectors (3 to 12 years) make them a more cost-effective alternative to glazed collection systems. As of 2015, over 4000 systems with a combined collector area of 500,000 m (100 acres) had been installed worldwide. Representatives include an 860 m (9,300 sq. ft.) collector in Costa Rica used for drying coffee beans and

7548-451: The major results of the energy released, which is not provided by the emissions from other wavelengths. See also Magnetar#1979 discovery detection of a soft gamma repeater . Observation of gamma rays first became possible in the 1960s. Their observation is much more problematic than that of X-rays or of visible light, because gamma-rays are comparatively rare, even a "bright" source needing an observation time of several minutes before it

7650-511: The medium to transfer the heat to their destination. The sun’s free energy can also be used to heat water to fulfil domestic hot water demands, such as the hot water that comes out of taps. Solar thermal water heating systems can provide approximately 50% of a property’s annual hot water demand (depending on the size of the property, its location etc) which in turn can help homeowners make savings on their energy bills. A collection of mature technologies called seasonal thermal energy storage (STES)

7752-412: The mirrors or lenses do not move, then the focus of the mirrors or lenses changes. A tracking system that follows the position of the sun is required. The tracking system increases the cost and complexity. With this in mind, different designs can be distinguished in how they concentrate the light and track the position of the sun. Parabolic trough power plants use a curved, mirrored trough which reflects

7854-419: The mirrors to track the sun and focus its light onto a network of stationary steel pipes, also suspended from the glasshouse structure. Steam is generated directly, using oil field-quality water, as water flows from the inlet throughout the length of the pipes, without heat exchangers or intermediate working fluids. The steam produced is then fed directly to the field’s existing steam distribution network, where

7956-628: The moisture. Solar cookers use sunlight for cooking, drying and pasteurization . Solar cooking offsets fuel costs, reduces demand for fuel or firewood, and improves air quality by reducing or removing a source of smoke. The simplest type of solar cooker is the box cooker first built by Horace de Saussure in 1767. A basic box cooker consists of an insulated container with a transparent lid. These cookers can be used effectively with partially overcast skies and will typically reach temperatures of 50–100 °C (100° to 200 °F). Concentrating solar cookers use reflectors to concentrate solar energy onto

8058-593: The most land-efficient energy resources available: The federal government has dedicated nearly 2,000 times more acreage to oil and gas leases than to solar development. In 2010 the Bureau of Land Management approved nine large-scale solar projects, with a total generating capacity of 3,682 megawatts, representing approximately 40,000 acres. In contrast, in 2010, the Bureau of Land Management processed more than 5,200 applications gas and oil leases, and issued 1,308 leases, for

8160-439: The need for a reliable, two-axis tracking system that could maintain focus on the tower. Rigidity of the structure was a major concern in terms of wind load resistance and durability, but shading of the mirrors by support structures was to be avoided. The project produced 7 MW of electricity using 1,818 heliostats of 40 m (430 ft) reflective surface area each, with a total area of 72,650 m (782,000 ft). Solar One

8262-498: The number of photons that can be detected. Larger area detectors and better background suppression are essential for progress in the field. A discovery in 2012 may allow focusing gamma-ray telescopes. At photon energies greater than 700 keV, the index of refraction starts to increase again. On June 19, 1988, from Birigüi (50° 20' W, 21° 20' S) at 10:15 UTC a balloon launch occurred which carried two NaI(Tl) detectors ( 600 cm total area) to an air pressure altitude of 5.5 mb for

8364-421: The occurrence of no-flow high temperature stresses called stagnation which would otherwise reduce the life expectancy of collectors. Solar thermal energy can be useful for drying wood for construction and wood fuels such as wood chips for combustion. Solar is also used for food products such as fruits, grains, and fish. Crop drying by solar means is environmentally friendly as well as cost effective while improving

8466-464: The plane of the Milky Way galaxy. Cosmic radiation with the highest energy triggers electron-photon cascades in the atmosphere, while lower-energy gamma rays are only detectable above it. Gamma-ray bursts , like GRB 190114C , are transient phenomena challenging our understanding of high-energy astrophysical processes , ranging from microseconds to several hundred seconds. Gamma rays are difficult to detect due to their high energy and their blocking by

8568-430: The quality. The less money it takes to make a product, the less it can be sold for, pleasing both the buyers and the sellers. Technologies in solar drying include ultra low cost pumped transpired plate air collectors based on black fabrics. Solar thermal energy is helpful in the process of drying products such as wood chips and other forms of biomass by raising the temperature while allowing air to pass through and get rid of

8670-503: The receiver and becomes very hot. Common fluids are synthetic oil, molten salt and pressurized steam. The fluid containing the heat is transported to a heat engine where about a third of the heat is converted to electricity. Full-scale parabolic trough systems consist of many such troughs laid out in parallel over a large area of land. Since 1985 a solar thermal system using this principle has been in full operation in California in

8772-436: The receiver. However, seasonal changes in the angle of sunlight parallel to the trough does not require adjustment of the mirrors, since the light is simply concentrated elsewhere on the receiver. Thus the trough design does not require tracking on a second axis. The receiver may be enclosed in a glass vacuum chamber. The vacuum significantly reduces convective heat loss. A fluid (also called heat transfer fluid) passes through

8874-501: The solar bowl uses a fixed spherical reflector with a receiver which tracks the focus of light as the Sun moves across the sky. The solar bowl's receiver reaches temperature of 150 °C (300 °F) that is used to produce steam that helps cook 2,000 daily meals. Many other solar kitchens in India use another unique concentrating technology known as the Scheffler reflector. This technology

8976-434: The sources of these enigmatic high-energy flashes remain a mystery. They appear to come from far away in the Universe, and currently the most likely theory seems to be that at least some of them come from so-called hypernova explosions—supernovas creating black holes rather than neutron stars . Nuclear gamma rays were observed from the solar flares of August 4 and 7, 1972, and November 22, 1977. A solar flare

9078-614: The steam is continuously injected deep into the oil reservoir. Sheltering the mirrors from the wind allows them to achieve higher temperature rates and prevents dust from building up as a result from exposure to humidity. GlassPoint Solar , the company that created the Enclosed Trough design, states its technology can produce heat for EOR for about $ 5 per million British thermal units in sunny regions, compared to between $ 10 and $ 12 for other conventional solar thermal technologies. Gamma-ray astronomy Gamma-ray astronomy

9180-719: The steam turbine. With day and some nighttime operation of the steam-turbine Andasol 1 at 50 MW peak capacity produces more energy than Nevada Solar One at 64 MW peak capacity, due to the former plant's thermal energy storage system and larger solar field. The 280MW Solana Generating Station came online in Arizona in 2013 with 6 hours of power storage. Hassi R'Mel integrated solar combined cycle power station in Algeria and Martin Next Generation Solar Energy Center both use parabolic troughs in

9282-818: The study of extra-solar, and especially extragalactic , astronomy, new observations may complicate some prior models and findings. Future developments in gamma-ray astronomy will integrate data from gravitational wave and neutrino observatories ( Multi-messenger astronomy ), enriching our understanding of cosmic events like neutron star mergers. Technological advancements, including advanced mirror designs, better camera technologies, improved trigger systems, faster readout electronics , high-performance photon detectors like Silicon photomultipliers (SiPMs), alongside innovative data processing algorithms like time-tagging techniques and event reconstruction methods, will enhance spatial and temporal resolution . Machine learning algorithms and big data analytics will facilitate

9384-1150: The summer. Solar thermal energy Solar thermal energy ( STE ) is a form of energy and a technology for harnessing solar energy to generate thermal energy for use in industry , and in the residential and commercial sectors. Solar thermal collectors are classified by the United States Energy Information Administration as low-, medium-, or high-temperature collectors. Low-temperature collectors are generally unglazed and used to heat swimming pools or to heat ventilation air. Medium-temperature collectors are also usually flat plates but are used for heating water or air for residential and commercial use. High-temperature collectors concentrate sunlight using mirrors or lenses and are generally used for fulfilling heat requirements up to 300 ° C (600 °F) / 20 bar (300 psi) pressure in industries, and for electric power production. Two categories include Concentrated Solar Thermal (CST) for fulfilling heat requirements in industries, and Concentrated Solar Power (CSP) when

9486-738: The technologies involved. A solar chimney (or thermal chimney) is a passive solar ventilation system composed of a hollow thermal mass connecting the interior and exterior of a building. As the chimney warms, the air inside is heated causing an updraft that pulls air through the building. These systems have been in use since Roman times and remain common in the Middle East. Solar process heating systems are designed to provide large quantities of hot water or space heating for nonresidential buildings. Evaporation ponds are shallow ponds that concentrate dissolved solids through evaporation . The use of evaporation ponds to obtain salt from sea water

9588-495: The vicinity of the Earth. Later detectors determined that these gamma-ray bursts are seen to last for fractions of a second to minutes, appearing suddenly from unexpected directions, flickering, and then fading after briefly dominating the gamma-ray sky. Studied since the mid-1980s with instruments on board a variety of satellites and space probes, including Soviet Venera spacecraft and the Pioneer Venus Orbiter ,

9690-598: The world's largest thermal solar power plant is in the United Arab Emirates . Systems for utilizing low-temperature solar thermal energy include means for heat collection; usually heat storage, either short-term or interseasonal; and distribution within a structure or a district heating network. In some cases a single feature can do more than one of these things (e.g. some kinds of solar collectors also store heat). Some systems are passive, others are active (requiring other external energy to function). Heating

9792-697: Was 40 to 70% over the prior seven years. It is a niche market because the economics are challenging, with the annual number of cooling hours a limiting factor. Respectively, the annual cooling hours are roughly 1000 in the Mediterranean, 2500 in Southeast Asia, and only 50 to 200 in Central Europe. However, system construction costs dropped about 50% between 2007 and 2011. The International Energy Agency (IEA) Solar Heating and Cooling program (IEA-SHC) task groups working on further development of

9894-559: Was completed in 1981 and was operational from 1982 to 1986. Later redesigned and renamed Solar Two, it could be seen from Interstate 40 where it covered a 51  hectare (126  acre ) site, not including the administration building or rail yard facilities shared with a neighboring plant. Solar One/Two and other nearby solar projects are plainly visible via satellite imaging software at 34°52′18″N 116°50′03″W  /  34.87167°N 116.83417°W  / 34.87167; -116.83417 . During times of high winds, blowing dust

9996-615: Was converted into Solar Two , by adding a second ring of 108 larger 95 m (1,000 ft) heliostats around the existing Solar One, totaling 1926 heliostats with a total area of 82,750 m (891,000 ft). This gave Solar Two the ability to produce 10 megawatts—enough to power an estimated 7,500 homes. Solar Two used molten salt, a combination of 60%  sodium nitrate and 40%  potassium nitrate , as an energy storage medium instead of oil or water as with Solar One. This helped in energy storage during brief interruptions in sunlight due to clouds. The molten salt also allowed

10098-401: Was first developed by Wolfgang Scheffler in 1986. A Scheffler reflector is a parabolic dish that uses single axis tracking to follow the Sun's daily course. These reflectors have a flexible reflective surface that is able to change its curvature to adjust to seasonal variations in the incident angle of sunlight. Scheffler reflectors have the advantage of having a fixed focal point which improves

10200-644: Was launched in October 2000 (on a nominally 2-year mission) and was still operational (but fading) in March 2007. The HETE-2 mission ended in March 2008. Swift , a NASA spacecraft, was launched in 2004 and carries the BAT instrument for gamma-ray burst observations. Following BeppoSAX and HETE-2, it has observed numerous X-ray and optical counterparts to bursts, leading to distance determinations and detailed optical follow-up. These have established that most bursts originate in

10302-471: Was located in Daggett , CA , about 10 miles (16 km) east of Barstow. Solar One's method of collecting energy was based on concentrating the sun's energy onto a common focal point to produce heat to run a steam turbine generator. It had hundreds of large mirror assemblies, or heliostats , that track the sun, reflecting the solar energy onto a 328 ft (100 m) tall tower where a black receiver absorbed

10404-504: Was successfully demonstrated at a hospital in Mumbai in conjunction with IIT Bombay , Indian Institute of Technology . Where temperatures below about 95 °C (200 °F) are sufficient, as for space heating, flat-plate collectors of the nonconcentrating type are generally used. Because of the relatively high heat losses through the glazing, flat plate collectors will not reach temperatures much above 200 °C (400 °F) even when

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