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132-815: The seawater greenhouse concept was first researched and developed in 1991 by Charlie Paton's company Light Works Ltd, which is now known as the Seawater Greenhouse Ltd. Charlie Paton and Philip Davies worked on the first pilot project commenced in 1992, on the Canary Island of Tenerife . A prototype seawater greenhouse was assembled in the UK and constructed on the site in Tenerife covering an area of 360 m. The temperate crops successfully cultivated included tomatoes, spinach, dwarf peas, peppers, artichokes, French beans, and lettuce. The second pilot design

264-647: A World Heritage Site in Tenerife . Mount Teide is the highest peak in Spain and the 3rd tallest volcano in the world , measured from its base on the ocean floor. The islands have warm summers and winters warm enough for the climate to be technically tropical at sea level. The amount of precipitation and the level of maritime moderation vary depending on location and elevation. The archipelago includes green areas as well as semi-desert. The islands' high mountains are ideal for astronomical observation, because they lie above

396-444: A biosphere reserve by UNESCO . Geologically it is one of the oldest of the archipelago. The insular capital is San Sebastian de La Gomera . Garajonay National Park is located on the island. Lanzarote is the easternmost island and one of the oldest of the archipelago, and it has shown evidence of recent volcanic activity. It has a surface of 845.94 km (326.62 sq mi), and a population of 149,183 inhabitants, including

528-418: A fixed mirror distributed focus solar power system . The main reason for its development was to eliminate the cost of moving a large mirror to track the sun as with parabolic dish systems. A fixed parabolic mirror creates a variously shaped image of the sun as it moves across the sky. Only when the mirror is pointed directly at the sun does the light focus on one point. That is why parabolic dish systems track

660-437: A stippling pattern and one or two anti-reflective coatings to further enhance transparency . The absorber coating is typically a selective coating, where selective stands for having the special optical property to combine high absorption in the visible part of the electromagnetic spectrum coupled to low emittance in the infrared one. This creates a selective surface , which reduces black body energy emission from

792-681: A 2024 study by the University of Las Palmas de Gran Canaria, there is archaeological evidence that the Romans were the first to colonise the islands, during the period from the 1st century BCE to the 1st century CE. There was no overlap with the occupation by the people who were inhabiting the islands at the time of the Spanish conquest, who had first arrived sometime between the 1st and 3rd centuries CE. As José Farrujia describes, 'The indigenous Canarians lived mainly in natural caves, usually near

924-456: A circuit consisting of the evaporators, solar heating pipe, and condenser with an intake of seawater and an output of fresh water. The fresh water is produced by hot and relatively high humidity air which can produce sufficient distilled water for irrigation. The volume of fresh water is determined by air temperature, relative humidity, solar radiation and the airflow rate. These conditions can be modeled with appropriate meteorological data, enabling

1056-401: A condenser, fans, seawater and distilled water pipes and crops in between the two evaporators. This is shown in schematic figures 1 and 2. The process recreates the natural hydrological cycle within a controlled environment of the greenhouse by evaporating water from saline water source and regains it as freshwater by condensation. The first part of the system uses seawater, an evaporator, and

1188-522: A condenser. The front wall of the greenhouse consists of a seawater-wetted evaporator which faces the prevailing wind. These are mostly constituted of corrugated cardboard shown in Figure 3. If the wind is not prevalent enough, fans blow the outside air through the evaporator into the greenhouse. The ambient warm air exchanges the heat with the seawater which cools it down and gets it humidified. The cool and humid air creates an adequate growing environment for

1320-404: A discontinuous absorbance area. An array of evacuated tubes collectors on a roof has space between the individual tubes and a vacuum gap between each tube and its absorber inside, covering only a fraction of the installation area on a roof. If evacuated tubes are compared with flat-plate collectors on the basis of the area of roof occupied (gross area), a different conclusion might be reached than if

1452-426: A gravel bed for heat storage. Ventilation, fresh air or makeup air is required in most commercial, industrial and institutional buildings to meet code requirements. By drawing air through a properly designed unglazed transpired air collector or an air heater, the solar heated fresh air can reduce the heating load during daytime operation. Many applications are now being installed where the transpired collector preheats

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1584-410: A heat exchanger, temperatures need not be quite so high for the circulation system to be switched on, so such direct circulation panels, whether polymer or otherwise, can be more efficient, particularly at low solar irradiance levels. Some early selectively coated polymer collectors suffered from overheating when insulated, as stagnation temperatures can exceed the polymer's melting point. For example,

1716-419: A heat-transfer fluid to drive a turbine connected to an electrical generator . Flat-plate and evacuated-tube solar collectors are mainly used to collect heat for space heating, domestic hot water, or cooling with an absorption chiller . In contrast to solar hot water panels, they use a circulating fluid to displace heat to a separated reservoir. The first solar thermal collector designed for building roofs

1848-422: A high conductivity metal sheet (copper or aluminum). A dark coating is applied to the sun-facing side of the absorber assembly to increase its absorption of solar energy. A common absorber coating is black enamel paint. In higher performance solar collector designs, the transparent cover is tempered soda-lime glass having reduced iron oxide content same as for photovoltaic solar panels . The glass may also have

1980-577: A large degree of autonomy. In fact, the islands do not enjoy any special degree of autonomy, as each one of the Spanish regions is considered an autonomous community , with equal status to the European ones. Under the Law of the Sea , the only islands not granted territorial waters or an exclusive economic zone (EEZ) are those that are not fit for human habitation, or do not have an economic life of their own, which

2112-446: A life expectancy of over 25 years. . Evacuated tube collectors are the most common solar thermal technology in the world. They make use of a glass tube to surround the absorber with high vacuum and effectively resist atmospheric pressure . The vacuum that surrounds the absorber greatly reduces convection and conduction heat loss, therefore achieving greater energy conversion efficiency . The absorber can be either metallic as in

2244-527: A perforated material and is heated from the conductive properties of the material and the convective properties of the moving air. Through-pass absorbers have the most surface area which enables relatively high conductive heat transfer rates, but significant pressure drop can require greater fan power, and deterioration of certain absorber material after many years of solar radiation exposure can additionally create problems with air quality and performance. In back-pass, front-pass, and combination type configurations

2376-399: A pilot facility. The bowl had a diameter of 65 ft (20 m), tilted at a 15° angle to optimize the cost/yield relation (33° would have maximized yield). The rim of the hemisphere was "trimmed" to 60°, creating a maximum aperture of 3,318 square feet (308.3 m ). This pilot bowl produced electricity at a rate of 10 kW peak. A 15-metre (49 ft) diameter Auroville solar bowl

2508-503: A protective metal or plastic case also used for fixing to supports. Glass-metal evacuated tubes are made with flat or curved metal absorber sheets same as those of flat plates. These sheets are joined to pipes or heat pipes to make "fins" and placed inside a single borosilicate glass tube. An anti-reflective coating can be deposited on the inner and outer surfaces of such tubes to improve transparency. Both selective and anti-reflective coating (inner tube surface) will not degrade until

2640-456: A shading system which retains core evaporative cooling elements. The Sahara Forest Project (SFP) combines the seawater greenhouse technology and concentrated solar power and constructed pilot projects in Jordan and Qatar. The seawater greenhouse evaporates 50 m of seawater and harvests 5 m of fresh water per hectare per day. The solar power production capacity through PV panels produces 39 kW on

2772-427: A site occupied from 1,600 years ago up until the 1960s, round stone houses, complex burial sites, and associated artefacts have been found. Across the islands are thousands of Libyco-Berber alphabet inscriptions scattered and they have been extensively documented by many linguists. The social structure of indigenous Canarians encompassed "a system of matrilineal descent in most of the islands, in which inheritance

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2904-439: A thermal one-way valve due to their heat pipes. This gives them an inherent maximum operating temperature that acts as a safety feature. Evacuated tubes collectors can also be provided with low concentrating reflectors at the back of the tubes realising a CPC collector. A longstanding argument exists between proponents of these two technologies. Some of this can be related to the structure of evacuated tube collectors which have

3036-620: A transpired collector with a lower air outlet position and perforated cavity framing to perpetrate increased air turbulence behind the perforated absorber for increased performance. This cutaway view shows the MatrixAir transpired solar collector components and air flow. The lower air inlet mitigates the intake of heated air to the HVAC system during summer operation. The extensive monitoring by Natural Resources Canada and NREL has shown that transpired solar collector systems reduce between 10-50% of

3168-442: A volcanic ridge on La Palma, in 2021 . The Teide volcano on Tenerife is the highest mountain in Spain, and the third tallest volcano on Earth on a volcanic ocean island. All the islands except La Gomera have been active in the last million years. Four of them, Lanzarote, Tenerife, La Palma and El Hierro, have historical records of eruptions since European discovery. The islands rise from Jurassic oceanic crust associated with

3300-501: Is La Graciosa , which administratively is dependent on Lanzarote. The archipelago includes many smaller islands and islets, including Alegranza , Isla de Lobos , Montaña Clara , Roque del Oeste , and Roque del Este . It includes a number of rocks, including Garachico and Anaga . In ancient times, the island chain was often referred to as "the Fortunate Isles". The Canary Islands are the southernmost region of Spain , and

3432-513: Is 1,560 km (600 sq mi). Roque Nublo 1,813 metres (5,948 feet) and Pico de las Nieves ("Peak of Snow") 1,949 metres (6,394 feet) are located in the center of the island. On the south of the island are the Maspalomas Dunes (Gran Canaria). La Gomera (informally known as 'Isla Colombina') has an area of 369.76 km (142.77 sq mi) and is the second least populous island with 21,136 inhabitants. It has been declared

3564-546: Is a renewable energy heating technology used to heat or condition air for buildings or process heat applications. It is typically the most cost-effective of all the solar technologies, especially in large scale applications, and it addresses the largest usage of building energy in heating climates, which is space heating and industrial process heating. They are either glazed or unglazed. Unglazed air collectors heat ambient (outside) air instead of recirculated building air. Transpired solar collectors are usually wall-mounted to capture

3696-409: Is expected so that they do not crack. Many metal collectors are installed as part of a sealed heat exchanger system. Rather than having potable water flow directly through the collectors, a mixture of water and antifreeze such as propylene glycol is used. A heat exchange fluid protects against freeze damage down to a locally determined risk temperature that depends on the proportion of propylene glycol in

3828-403: Is in residential buildings where the demand for hot water has a large impact on energy bills. This generally means a situation with a large family or a situation in which the hot water demand is excessive due to frequent laundry washing. Commercial applications include laundromats, car washes, military laundry facilities and eating establishments. The technology can also be used for space heating if

3960-496: Is mostly concentrated in the two capital islands: around 43% on the island of Tenerife and 40% on the island of Gran Canaria. The Canary Islands, especially Tenerife, Gran Canaria, Fuerteventura, and Lanzarote, are a major tourist destination, with over 16 million visitors in 2023. This is due to their beaches, subtropical climate , and important natural attractions, especially Maspalomas in Gran Canaria and Mount Teide ,

4092-719: Is no unambiguous evidence that the two designs differ in long-term reliability. However, evacuated tube technology (especially for newer variants with glass-metal seals and heat pipes) still needs to demonstrate competitive lifetimes. The modularity of evacuated tubes can be advantageous in terms of extensibility and maintenance, for example, if the vacuum in one heat pipe tube is lost it can be easily be replaced with minimal effort. In most climates, flat plate collectors will generally be more cost-effective than evacuated tubes. However, evacuated tube collectors are well-suited to cold ambient temperatures and work well in situations of low solar irradiance, providing heat more consistently throughout

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4224-722: Is not the case of the Canary Islands. There are some pro-independence political parties, like the National Congress of the Canaries (CNC) and the Popular Front of the Canary Islands . Their popular support is almost insignificant, with no presence in either the autonomous parliament or the cabildos insulares . In a 2012 study by the Centro de Investigaciones Sociológicas , when asked about national identity,

4356-464: Is now western Morocco in the early first century  AD . That same naval force was subsequently sent on an exploration of the Canary Islands, using Mogador as their mission base. The names given by Romans to the individual islands were Ninguaria or Nivaria (Tenerife), Canaria (Gran Canaria), Pluvialia or Invale (Lanzarote), Ombrion (La Palma), Planasia (Fuerteventura), Iunonia or Junonia (El Hierro) and Capraria (La Gomera). From

4488-425: Is placed inside the inner tube at atmospheric pressure. Glass-glass tubes have a very reliable seal, but the two layers of glass reduce the amount of sunlight that reaches the absorber. The selective coating can be deposited on the inner borosilicate tube (high vacuum side) to avoid this, but heat has then to flow through the poorly conducting glass thickness of the inner tube in this case. Moreover, moisture may enter

4620-584: Is retained in their depiction on the islands' coat-of-arms. Other theories speculate that the name comes from the Nukkari Berber tribe living in the Moroccan Atlas, named in Roman sources as Canarii , though Pliny again mentions the relation of this term with dogs. The name of the islands is not derived from the canary bird ; rather, the birds are named after the islands. From west to east,

4752-471: Is the highest peak of Spain and a World Heritage Site . Tenerife is the site of the worst air disaster in the history of aviation, in which 583 people were killed in the collision of two Boeing 747s on 27 March 1977. Graciosa Island or commonly La Graciosa is a volcanic island in the Canary Islands of Spain, located 2 km (1.2 mi) north of the island of Lanzarote across the Strait of El Río. It

4884-517: Is the oldest of the islands being more eroded. Its highest point is the Peak of the Bramble, at a height of 807 metres (2,648 feet). Its capital is Puerto del Rosario . Gran Canaria has 846,717 inhabitants. The capital, Las Palmas de Gran Canaria , with 377,203 inhabitants, is the most populous city and shares the status of capital of the Canaries with Santa Cruz de Tenerife. Gran Canaria's surface area

5016-712: Is the second largest in the archipelago and located 100 km (62 mi) from the African coast. The islands form the Macaronesia ecoregion with the Azores , Cape Verde , Madeira , and the Savage Isles . The Canary Islands is the largest and most populated archipelago of the Macaronesia region. The archipelago has seven large and several smaller islands, all of which are volcanic in origin. According to

5148-578: Is usually counterbalanced. The receiver may consist of pipes carrying fluid for thermal transfer or photovoltaic cells for direct conversion of light to electricity. The solar bowl design resulted from a project of the Electrical Engineering Department of the Texas Technical University, headed by Edwin O'Hair, to develop a 5 MWe power plant. A solar bowl was built for the town of Crosbyton, Texas as

5280-564: The Canary hotspot . The Canary Islands is the only place in Spain where volcanic eruptions have been recorded during the Modern Era , with some volcanoes still active (El Hierro, 2011). Volcanic islands such as those in the Canary chain often have steep ocean cliffs caused by catastrophic debris avalanches and landslides . The island chain's most recent eruption occurred at Cumbre Vieja ,

5412-560: The Civil Guard are based in the territory. Before the arrival of humans, the Canaries were inhabited by prehistoric animals including the giant lizard ( Gallotia goliath ), the Tenerife and Gran Canaria giant rats , and giant tortoises, Geochelone burchardi and Geochelone vulcanica . Although the original settlement of what are now called the Canary Islands is not entirely clear, linguistic, genetic, and archaeological analyses indicate that indigenous peoples were living on

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5544-689: The Phoenicians , the Greeks , and the Carthaginians . King Juba II , Caesar Augustus 's Numidian protégé, is credited with discovering the islands for the Western world. According to Pliny the Elder , Juba found the islands uninhabited, but found "a small temple of stone" and "some traces of buildings". Juba dispatched a naval contingent to re-open the dye production facility at Mogador in what

5676-569: The Roques de Anaga , Garachico and Fasnia in Tenerife, and Salmor and Bonanza in El Hierro. El Hierro, the westernmost island, covers 268.71 km (103.75 sq mi). It is the second smallest of the major islands, and the least populous with 10,798 inhabitants. The whole island was declared a Reserve of the Biosphere in 2000. Its capital is Valverde . Also known as Ferro, it was once

5808-541: The Spanish Senate . Of these, 11 seats are directly elected, 3 for Gran Canaria, 3 for Tenerife, and 1 each for Lanzarote (including La Graciosa), Fuerteventura, La Palma, La Gomera and El Hierro. The other 3 are appointed by the regional legislature. The Autonomous Community of the Canary Islands has two provinces ( provincias ), Las Palmas and Santa Cruz de Tenerife , whose capitals, Las Palmas de Gran Canaria and Santa Cruz de Tenerife , are capitals of

5940-480: The dragon tree , Dracaena draco are endemic, as noted by Sabin Berthelot and Philip Barker Webb in their work, L'Histoire Naturelle des Îles Canaries (1835–50). The climate is warm subtropical / tropical and generally arid , moderated by the sea and in summer by the trade winds . There are a number of microclimates and the classifications range mainly from semi-desert to desert . The majority of

6072-559: The temperature inversion layer. As a result, the archipelago has two professional astronomical observatories: the Teide Observatory on Tenerife, and Roque de los Muchachos Observatory on La Palma. In 1927, the Province of Canary Islands was split into two provinces. In 1982, the autonomous community of the Canary Islands was established. The cities of Santa Cruz de Tenerife and Las Palmas de Gran Canaria are, jointly,

6204-721: The 14th century onward, numerous visits were made by sailors from Majorca , Portugal , and Genoa . Lancelotto Malocello settled on Lanzarote in 1312. The Majorcans established a mission with a bishop in the islands that lasted from 1350 to 1400. In 1402, the Castilian colonisation of the islands began with the expedition of the French explorers Jean de Béthencourt and Gadifer de la Salle , nobles and vassals of Henry III of Castile , to Lanzarote. From there, they went on to conquer Fuerteventura (1405) and El Hierro. These invasions were "brutal cultural and military clashes between

6336-459: The 3 hectares area with 1350 m growing area. The greenhouses are 15 degrees cooler than the outside temperatures which enables the production up to 130,000 of kg of vegetables per year and up to 20,000 liters of fresh water per day. Additionally, the project includes revegetation by soil reclamation of nitrogen-fixing and salt-removing desert plants by repurposed waste products from agriculture and saltwater evaporation. A seawater greenhouse uses

6468-400: The African coast, the influence of the current diminishes, and the islands become increasingly arid. Fuerteventura and Lanzarote , the islands which are closest to the African mainland, are effectively desert or semi-desert. Gran Canaria is known as a "continent in miniature" for its diverse landscapes like Maspalomas and Roque Nublo . The north of Tenerife lies under the influence of

6600-717: The Canaries , are a Spanish region, autonomous community and archipelago in the Atlantic Ocean . At their closest point to the African mainland, they are 100 kilometres (62 miles) west of Morocco . They are the southernmost of the autonomous communities of Spain . The islands have a population of 2.2 million people and are the most populous special territory of the European Union . The seven main islands are from largest to smallest in area, Tenerife , Fuerteventura , Gran Canaria , Lanzarote , La Palma , La Gomera , and El Hierro . The only other populated island

6732-481: The Canary Island's territorial waters as being Moroccan coast and Morocco has authorised gas and oil exploration in what the Canary Islands states to be Canarian territorial waters and Western Sahara waters. Morocco's official position is that international laws regarding territorial limits do not authorise Spain to claim seabed boundaries based on the territory of the Canaries, since the Canary Islands enjoy

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6864-536: The Canary Islands are El Hierro , La Palma , La Gomera , Tenerife , Gran Canaria , Fuerteventura , Lanzarote , and La Graciosa . North of Lanzarote are the islets of Montaña Clara , Alegranza , Roque del Este and Roque del Oeste , belonging to the Chinijo Archipelago . Northeast of Fuerteventura is the islet of Lobos . There are a series of small adjacent rocks in the Canary Islands:

6996-561: The Canary Islands at least 2,000 years ago, possibly 3,000, and that they shared a common origin with the Berbers on the nearby North African coast. Reaching the islands may have taken place using several small boats, landing on the easternmost islands Lanzarote and Fuerteventura. These groups came to be known collectively as the Guanches , although Guanches had been the name for only the indigenous inhabitants of Tenerife. According to

7128-520: The Canary Islands have a hot desert climate ( BWh ) and a hot semi-desert climate ( BSh ) within the Köppen system, caused partly due to the cool Canary Current . A subtropical humid climate, which is very influenced by the ocean, is in the middle of the islands of La Gomera , Tenerife and La Palma , where laurisilva cloud forests grow. The seven major islands, one minor island, and several small islets were originally volcanic islands, formed by

7260-578: The Canary Islands: Solar thermal collector A solar thermal collector collects heat by absorbing sunlight . The term "solar collector" commonly refers to a device for solar hot water heating , but may refer to large power generating installations such as solar parabolic troughs and solar towers or non- water heating devices such as solar cookers or solar air heaters . Solar thermal collectors are either non-concentrating or concentrating. In non-concentrating collectors,

7392-631: The Teide National Park was declared one of the 12 Treasures of Spain . The regional executive body, the Parliament of the Canary Islands , is presided over by Fernando Clavijo Batlle ( Canarian Coalition ), the current President of the Canary Islands . The members of the regional legislature, the Parliament of the Canary Islands , has 70 elected legislators. The last regional election took place in May 2023. The islands have 14 seats in

7524-465: The absorber and improves performance. Piping can be laser or ultrasound welded to the absorber sheet to reduce damage to the selective coating, which is typically applied prior to joining to large coils in a roll-to-roll process . Absorber piping configurations include: A flat plate collector making use of a honeycomb structure to reduce heat loss also at the glass side too has also been made available commercially. Most flat plate collectors have

7656-455: The absorber or aperture areas were compared. The recent revision of the ISO 9806 standard states that the efficiency of solar thermal collectors should be measured in terms of gross area and this might favour flat plates in respect to evacuated tube collectors in direct comparisons. Flat-plate collectors usually lose more heat to the environment than evacuated tubes because there is no insulation at

7788-462: The absorber. Non-transparent glazing materials are less expensive and decrease expected payback periods. Transpired collectors are considered "unglazed" because their collector surfaces are exposed to the elements, are often not transparent and not hermetically sealed. The term "unglazed air collector" refers to a solar air heating system that consists of a metal absorber without any glass or glazing over top. The most common type of unglazed collector on

7920-471: The adjacent islets of the Chinijo Archipelago. The capital is Arrecife , with 56,834 inhabitants. The Chinijo Archipelago includes the islands La Graciosa , Alegranza , Montaña Clara , Roque del Este and Roque del Oeste . It has a surface of 40.8 km (15.8 sq mi), and only La Graciosa is populated, with 658 inhabitants. With 29 km (11 sq mi), La Graciosa is

8052-495: The advantages of both flat plate and evacuated tube collectors combined together. They surround a large area metal sheet absorber with high vacuum inside a flat envelope made of glass and metal. They offer the highest energy conversion efficiency of any non-concentrating solar thermal collector, but require sophisticated technology for manufacturing. They should not be confused with flat plate collectors featuring low vacuum inside. The first collector making use of high vacuum insulation

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8184-469: The air is directed on either the back, the front, or on both sides of the absorber to be heated from the return to the supply ducting headers. Although passing the air on both sides of the absorber will provide a greater surface area for conductive heat transfer, issues with dust (fouling) can arise from passing air on the front side of the absorber which reduces absorber efficiency by limiting the amount of sunlight received. In cold climates, air passing next to

8316-410: The amount of captured sunlight, producing what is called the sinus effect of power output. Proponents of the solar bowl design claim the reduction in overall power output compared with tracking parabolic mirrors is offset by lower system costs. The sunlight concentrated at the focal line of a spherical reflector is collected using a tracking receiver. This receiver is pivoted around the focal line and

8448-400: The aperture area (i.e., the area that receives the solar radiation ) is roughly the same as the absorber area (i.e., the area absorbing the radiation). A common example of such a system is a metal plate that is painted a dark color to maximize the absorption of sunlight. The energy is then collected by cooling the plate with a working fluid , often water or glycol running in pipes attached to

8580-521: The autonomous community. Each of the seven major islands are ruled by an island council named a Cabildo Insular . Each island is subdivided into smaller municipalities ( municipios ). Las Palmas is divided into 34 municipalities , and Santa Cruz de Tenerife is divided into 54 municipalities . The international boundary of the Canaries is disputed in Morocco-Spain relations . In 2022 the UN declared

8712-694: The available collector area, the bulk of the water heating can be done at low temperature, lower than swimming pool temperatures where unglazed collectors are well established in the marketplace as the right choice. Because these collectors need not withstand high temperatures, they can use less expensive materials such as plastic or rubber. Many unglazed collectors are made of polypropylene and must be drained fully to avoid freeze damage when air temperatures drop below 44 °F (7 °C) on clear nights. A smaller but growing percentage of unglazed collectors are flexible meaning they can withstand water freezing solid inside their absorber. The freeze concern only needs to be

8844-477: The bird Serinus canaria (canary) and the Phoenix canariensis palm. Four of Spain's thirteen national parks are located in the Canary Islands, more than any other autonomous community. Two of these have been declared UNESCO World Heritage Sites and the other two are part of Biosphere Reserves . The parks are: Teide National Park is the oldest and largest national park in the Canary Islands and one of

8976-462: The building envelope or from the outdoor environment and passing it through the collector where the air warms via conduction from the absorber and is then supplied to the living or working space by either passive means or with the assistance of a fan. A pioneering figure of this type of system was George Löf, who built a solar-heated air system in 1945 for a house in Boulder, Colorado. He later included

9108-486: The building is located off-grid or if utility power is subject to frequent outages. Solar water heating systems are most likely to be cost effective for facilities with water heating systems that are expensive to operate, or with operations such as laundries or kitchens that require large quantities of hot water. Unglazed liquid collectors are commonly used to heat water for swimming pools but can also be applied to large-scale water pre-heating. When loads are large relative to

9240-406: The capitals of the islands. Those cities are also, respectively, the capitals of the provinces of Santa Cruz de Tenerife and Las Palmas . Las Palmas de Gran Canaria has been the largest city in the Canaries since 1768, except for a brief period in the 1910s. Between the 1833 territorial division of Spain and 1927, Santa Cruz de Tenerife was the sole capital of the Canary Islands. In 1927, it

9372-418: The case of flat plate collectors or being a second concentric glass tube ("Sydney Tube"). Heat transfer fluid can flow in and out of each tube or being in contact with a heat pipe reaching inside the tube. For the latter, heat pipes transfer heat to the fluid in a heat exchanger called a "manifold" placed transversely with respect to the tubes. The manifold is wrapped in insulation ( glass wool ) and covered by

9504-412: The coast, 300 to 500 metres (1,000 to 1,600 ft) above sea level. These caves were sometimes isolated but more commonly formed settlements, with burial caves nearby'. Archaeological work has uncovered a rich culture visible through artefacts of ceramics , human figures, fishing, hunting and farming tools, plant fibre clothing and vessels, as well as cave paintings. At Lomo de los Gatos on Gran Canaria,

9636-434: The costs of this alternative dramatically compared to the higher temperature collector types. When heating hot water, we are actually heating cold to warm and warm to hot. We can heat cold to warm as efficiently with unglazed collectors, just as we can heat warm to hot with high-temperature collectors. A simple solar air collector consists of an absorber material, sometimes having a selective surface, to capture radiation from

9768-604: The crop's irrigation demand. The third pilot seawater greenhouse, which is 864 m, is near Muscat in Oman which produces 0.3 to 0.6 m of freshwater per day. This project was created as a collaboration between Sultan Qaboos University. It provides an opportunity to develop a sustainable horticultural sector on the Batinah coast. These projects have enabled the validation of a thermodynamic simulation model which, given appropriate meteorological data, accurately predicts and quantifies how

9900-408: The crops. The remaining evaporatively-cooled seawater is collected and pumped to the condenser as a coolant. The second part of the system has another evaporator. The seawater flows from the first evaporator which preheats it and thereafter flows through the solar thermal collector on the roof to heat it up sufficiently before it flows to the second evaporator. The seawater, or coolant, flows through

10032-559: The design and process to be optimized for any suitable location. The technique is applicable to sites in arid regions near the sea. The distance and elevation from the sea must be evaluated considering the energy required to pump water to the site. There are numerous suitable locations on the coasts; others are below sea level, such as the Dead Sea and the Qattara Depression , where hydro schemes have been proposed to exploit

10164-495: The desired output temperature is near the ambient temperature (that is, when it is warm outside). As the ambient temperature gets cooler, these collectors become less effective. A solar bowl is a type of solar thermal collector that operates similarly to a parabolic dish , but instead of using a tracking parabolic mirror with a fixed receiver, it has a fixed spherical mirror with a tracking receiver. This reduces efficiency but makes it cheaper to build and operate. Designers call it

10296-623: The environment and produce the most freshwater. The study found that a pipe array gave the best results: an air temperature decrease of 1 °C, a mean radiant temperature decrease of 7.5 °C, and a freshwater production increase of 63%. This can be implemented to improve seawater greenhouses in hot arid regions such as the second pilot design in the United Arab Emirates. In 2018, Paton and Davis researched brine utilization for cooling and salt production in wind-driven seawater greenhouses to design and model it. The brine disposed by

10428-443: The exterior panels. This heated ventilation air is drawn under negative pressure into the building's ventilation system where it is then distributed via conventional means or using a solar ducting system. Hot air that may enter an HVAC system connected to a transpired collector that has air outlets positioned along the top of the collector, particularly if the collector is west facing. To counter this problem, Matrix Energy has patented

10560-512: The field of ' solar co-generation ', solar thermal technologies are paired with photovoltaics (PV) to increase the efficiency of the system by taking heat away from the PV collectors, cooling the PV panels to improve their electrical performance while simultaneously warming air for space heating. Space heating for residential and commercial applications can be done through the use of solar air heating panels. This configuration operates by drawing air from

10692-440: The fresh air entering a heat recovery ventilator to reduce the defrost time of HRV's. The higher your ventilation and temperature the better your payback time will be. Solar air heat is also used in process applications such as drying laundry, crops ( i.e . tea, corn, coffee) and other drying applications. Air heated through a solar collector and then passed over a medium to be dried can provide an efficient means by which to reduce

10824-567: The front or back of the absorber plate while scrubbing heat directly from it. Heated air can then be distributed directly for applications such as space heating and drying or may be stored for later use. Payback for glazed solar air heating panels can be less than 9–15 years depending on the fuel being replaced. Unglazed systems, or transpired air systems have been used to heat make-up or ventilation air in commercial, industrial, agriculture and process applications. They consist of an absorber plate which air passes across or through as it scrubs heat from

10956-467: The glass side. Evacuated tube collectors intrinsically have a lower absorber to gross area ratio (typically 60–80% less) than flat plates because tubes have to be spaced apart. Although several European companies manufacture evacuated tube collectors (mainly glass-metal type), the evacuated tube market is dominated by manufacturers in China, with some companies having track records of 15–30 years or more. There

11088-431: The glazing will additionally cause greater heat loss, resulting in lower overall performance of the collector. Glazed systems usually have a transparent top sheet and insulated side and back panels to minimize heat loss to ambient air. The absorber plates in modern panels can have absorptivity of more than 93%. Glazed Solar Collectors (recirculating types that are usually used for space heating). Air typically passes along

11220-469: The hydraulic pressure to generate power, e.g., Red Sea–Dead Sea Canal . In 1996, Paton and Davies used the Simulink toolkit under MATLAB to model forced ventilation of the greenhouse in Tenerife, Cape Verde, Namibia, and Oman. The greenhouse is assisted by the prevailing wind, evaporative cooling, transpiration, solar heating, heat transfer through the walls and roof, and condensation which is analyzed in

11352-500: The indigenous population and the Castilians" lasting over a century due to formidable resistance by indigenous Canarians. Professor Mohamed Adhikari has defined the conquest of the islands as a genocide of the Guanches . Béthencourt received the title King of the Canary Islands, but still recognised King Henry III as his overlord. It was not a simple military enterprise, given the aboriginal resistance on some islands. Neither

11484-452: The island erupted . It is the second-highest island of the Canaries, with the Roque de los Muchachos at 2,423 metres (7,949 feet) as its highest point. Santa Cruz de La Palma , known to those on the island as simply "Santa Cruz", is its capital. Tenerife is, with its area of 2,034 km (785 sq mi), the most extensive island of the Canary Islands. With 904,713 inhabitants, it is

11616-424: The island of Lanzarote. It is the smallest and least populated of the main islands, with about 700 people. Tenerife is the largest and most populous island of the archipelago. Gran Canaria , with 865,070 inhabitants, is both the Canary Islands' second most populous island, and the third most populous one in Spain after Tenerife (966,354 inhabitants) and Majorca (896,038 inhabitants). The island of Fuerteventura

11748-424: The largest and most populous archipelago of Macaronesia . Because of their location, the Canary Islands have historically been considered a link between the four continents of Africa , North America , South America , and Europe . In 2023, the Canary Islands had a population of 2,236,013, with a density of 299 inhabitants per km , making it the seventh most populous autonomous community of Spain. The population

11880-408: The largest island of the Chinijo Archipelago and the smallest inhabited island of the Canaries. La Palma, with 81,863 inhabitants covering an area of 708.32 km (273.48 sq mi), is in its entirety a biosphere reserve. For long it showed no signs of volcanic activity, even though the volcano Teneguía entered into eruption last in 1971. On 19 September 2021, the volcanic Cumbre Vieja on

12012-460: The lower sun angle in the winter heating months as well as sun reflection off the snow and achieve their optimum performance and return on investment when operating at flow rates of between 4 and 8 CFM per square foot (72 to 144 m3/h.m2) of collector area. The exterior surface of a transpired solar collector consists of thousands of tiny micro-perforations that allow the boundary layer of heat to be captured and uniformly drawn into an air cavity behind

12144-549: The majority of respondents from the Canary Islands (53.8%) considered themselves Spanish and Canarian in equal measures, followed by 24% who consider themselves more Canarian than Spanish. 6.1% of the respondents considered themselves only Canarian, and 7% considered themselves only Spanish. The defense of the territory is the responsibility of the Spanish Armed Forces . Components of the Army , Navy , Air Force and

12276-457: The market is the transpired solar collector. The technology has been extensively monitored by these government agencies, and Natural Resources Canada developed the feasibility tool RETScreen™ to model the energy savings from transpired solar collectors. Since that time, several thousand transpired solar collector systems have been installed in a variety of commercial, industrial, institutional, agricultural, and process applications in countries around

12408-544: The melting point of polypropylene is 160 °C (320 °F), while the stagnation temperature of insulated thermal collectors can exceed 180 °C (356 °F) if control strategies are not used. For this reason, polypropylene is not often used in glazed selectively coated solar collectors. Increasingly, polymers such as high temperate silicones (which melt at over 250 °C (482 °F)) are being used. Some non polypropylene polymer based glazed solar collectors are matte black coated rather than selectively coated to reduce

12540-418: The mixture. The use of glycol lowers the water's heat carrying capacity marginally, while the addition of an extra heat exchanger may lower system performance at low light levels. A pool or unglazed collector is a simple form of flat-plate collector without a transparent cover. Typically, polypropylene or EPDM rubber or silicone rubber is used as an absorber. Used for pool heating, it can work quite well when

12672-417: The moist Atlantic winds and is well vegetated. The south of the island around the tourist resorts of Playa de las Américas and Los Cristianos is arid. The island rises to almost 4,000 m (13,000 ft) above sea level. At altitude, in the cool relatively wet climate, forests of the endemic pine Pinus canariensis thrive. Many of the plant species in the Canary Islands, like the Canary Island pine and

12804-403: The moisture content of the material. High temperature process heat can be produced by a solar furnace . Collectors are commonly classified by their air-ducting methods as one of three types: Collectors can also be classified by their outer surface: Offering the highest efficiency of any solar technology the through-pass configuration, air ducted onto one side of the absorber passes through

12936-499: The most common solar thermal technology in Europe . They consist of an (1) enclosure containing (2) a dark-colored absorber plate with fluid circulation passageways, and (3) a transparent cover to allow transmission of solar energy into the enclosure. The sides and back of the enclosure are typically insulated to reduce heat loss to the ambient. A heat transfer fluid is circulated through the absorber's fluid passageways to remove heat from

13068-457: The most populated island of the archipelago and Spain. Two of the islands' principal cities are located on it: the capital, Santa Cruz de Tenerife and San Cristóbal de La Laguna , a World Heritage Site. San Cristóbal de La Laguna , the second city of the island, is home to the oldest university in the Canary Islands, the University of La Laguna . Teide , with its 3,715 metres (12,188 feet)

13200-752: The need for antifreeze or heat exchangers. Hot water solar systems require heat exchangers due to contamination possibilities and in the case of unglazed collectors, the pressure difference between the solar working fluid (water) and the load (pressurized cold city water). Large-scale unglazed solar hot water heaters, like the one at the Minoru Aquatic Center in Richmond, BC operate at lower temperatures than evacuated tube or boxed and glazed collector systems. Although they require larger, more expensive heat exchangers, all other components including vented storage tanks and uninsulated plastic PVC piping reduce

13332-472: The non-evacuated area inside the inner tube and cause absorber corrosion in particular when made from dissimilar materials ( galvanic corrosion ). A Barium flash getter pump is commonly evaporated inside the high vacuum gap in between tubes to keep the internal pressure stable through time. The high temperatures that can occur inside evacuated tubes may require special design to prevent thermal shock and overheating . Some evacuated tube collectors work as

13464-519: The oldest in Spain. Located in the geographic centre of the island of Tenerife, it is the most visited national park in Spain. In 2010, it became the most visited national park in Europe and second worldwide. The park's highlight is the Teide volcano. Standing at an altitude of 3,715 metres (12,188 ft), it is the highest elevation in Spain and the third largest volcano on Earth from its base. In 2007,

13596-651: The opening of the Atlantic. Underwater magmatism began during the Cretaceous, and continued to the present day. The current islands reached the ocean's surface during the Miocene . The islands were once considered as a distinct physiographic section of the Atlas Mountains province, which is part of the larger African Alpine System division, but are now recognized as being related to a magmatic hot spot. In

13728-653: The plate. Concentrating collectors have a much larger aperture than the absorber area. The aperture is typically in the form of a mirror that is focussed on the absorber, which in most cases are the pipes carrying the working fluid. Due to the movement of the sun during the day, concentrating collectors often require some form of solar tracking system, and are sometimes referred to "active" collectors for this reason. Non-concentrating collectors are typically used in residential, industrial and commercial buildings for space heating , while concentrating collectors in concentrated solar power plants generate electricity by heating

13860-550: The position of the islands with respect to the north-east trade winds , the climate can be mild and wet or very dry. Several native species form laurisilva forests. The individual islands in the Canary archipelago tend to have distinct microclimates . Those islands such as El Hierro , La Palma and La Gomera lying to the west of the archipelago have a climate which is influenced by the moist Canary Current . They are well vegetated even at low levels and have extensive tracts of sub-tropical laurisilva forest. Travelling east toward

13992-588: The prevailing northeasterly trade winds . The name Islas Canarias is likely derived from the Latin name Canariae Insulae , meaning "Islands of the Dogs", perhaps because monk seals or sea dogs were abundant, a name that was evidently generalized from the ancient name of one of these islands, Canaria – presumably Gran Canaria. According to the historian Pliny the Elder , the island Canaria contained "vast multitudes of dogs of very large size". The connection to dogs

14124-462: The seawater desalination may disturb the ecosystem as the same amount of brine is produced as freshwater. By using the brine valoristation method of wind-driven air flow by cooling the greenhouse with seawater evaporation, salt can be produced as shown in Figure 4. This brine is the by-product of the freshwater production, but can also be the ingredient to make salt, making it into a product that can be merchandised. An additional finding of this research

14256-589: The seawater greenhouse will perform in other parts of the world. The fourth project is the commercial installation in Port Augusta , Australia, installed in 2010. It is currently a 20 hectare seawater greenhouse owned and run by Sundrop Farms which has developed it further. The fifth design was constructed in 2017 in Berbera , Somaliland. The design was researched to be simplified and inexpensive with advanced greenhouse modeling techniques. This design includes

14388-485: The solar collector. The circulation fluid in tropical and sub-tropical climates is typically water. In climates where freezing is likely, a heat transfer fluid similar to an automotive antifreeze solution may be used instead of water, or in a mixture with water. If a heat transfer fluid is used, a heat exchanger is typically employed to transfer heat from the solar collector fluid to a hot water storage tank. The most common absorber design consists of copper tubing joined to

14520-485: The stagnation temperature to 150 °C (302 °F) or less. In areas where freezing is a possibility, freeze-tolerance (the capability to freeze repeatedly without cracking) can be achieved by the use of flexible polymers. Silicone rubber pipes have been used for this purpose in UK since 1999. Conventional metal collectors are vulnerable to damage from freezing, so if they are water filled they must be carefully plumbed so they completely drain using gravity before freezing

14652-412: The study. They found that the amount of water required by the plants is reduced by 80% and 2.6-6.4 kWh electrical energy is needed for m3 of fresh water produced. In 2005, Paton and Davis Evaluated design options with thermal modeling using the United Arab Emirates model as a baseline. They studied three options:perforated screen, C-shaped air path, and pipe array, to find a better seawater circuit to cool

14784-463: The summer of 2011, a series of low-magnitude earthquakes occurred beneath El Hierro. These had a linear trend of northeast–southwest. In October a submarine eruption occurred about 2 km ( 1 + 1 ⁄ 4  mi) south of Restinga. This eruption produced gases and pumice, but no explosive activity was reported. The following table shows the highest mountains in each of the islands: The official natural symbols associated with Canary Islands are

14916-402: The sun and transfers this thermal energy to air via conduction heat transfer. This heated air is then ducted to the building space or to the process area where the heated air is used for space heating or process heating needs. Functioning in a similar manner as a conventional forced-air furnace, solar-thermal-air systems provide heat by circulating air over an energy collecting surface, absorbing

15048-552: The sun's thermal energy, and ducting air coming in contact with it. Simple and effective collectors can be made for a variety of air conditioning and process applications. Many applications can utilize solar air heat technologies to reduce the carbon footprint from the use of conventional heat sources, such as fossil fuels, to create a sustainable means to produce thermal energy. Applications such as space heating, greenhouse season extension , pre-heating ventilation makeup air, or process heat can be addressed by solar air heat devices. In

15180-402: The sun. A fixed spherical mirror focuses the light in the same place independent of the sun's position. The light, however, is not directed to one point but is distributed on a line from the surface of the mirror to one half radius (along a line that runs through the sphere center and the sun). As the sun moves across the sky, the aperture of any fixed collector changes. This causes changes in

15312-610: The surrounding environment to grow temperate crops and produce freshwater. A conventional greenhouse uses solar heat to create a warmer environment to allow adequate growing temperature, whereas the seawater greenhouse does the opposite by creating a cooler environment. The roof traps infrared heat, while allowing visible light through to promote photosynthesis . The design for cooling the microclimate primarily consists of humidification and dehumidification (HD) desalination process or multiple-effect humidification . A simple seawater greenhouse consists of two evaporative coolers (evaporators),

15444-432: The tubes may allow for snow to fall through the collector, minimizing the loss of production in some snowy conditions, though the lack of radiated heat from the tubes can also prevent effective shedding of accumulated snow. Flat plate collectors might be easier to clean. Other properties, such as appearance and ease of installation are more subjective and difficult to compare. Evacuated flat plate solar collectors provide all

15576-841: The type of collector. Different from evacuated tube collectors, they make use of non-evaporable getter (NEG) pumps to keep the internal pressure stable through time. This getter pump technology has the advantage of providing some regeneration in-situ by exposure to sunlight. Evacuated flat plate solar collectors have been studied for solar air condition and compared to compact solar concentrators. These collectors are an alternative to metal collectors. These may be wholly polymer , or they may include metal plates in front of freeze-tolerant water channels made of silicone rubber . Polymers are flexible and therefore freeze-tolerant and can employ plain water instead of antifreeze, so that they may be plumbed directly into existing water tanks instead of needing heat exchangers that lower efficiency. By dispensing with

15708-419: The vacuum is lost. A high vacuum-tight glass-metal seal is however required at one or both sides of each evacuated tube. This seal is cycled between ambient and fluid temperature each day of collector operation and might lead to failures in time. Glass-glass evacuated tubes are made with two borosilicate glass tubes fused together at one or both ends (similar a vacuum bottle or dewar flask). The absorber fin

15840-408: The water-filled piping and collector manifolds in a hard freeze condition. Unglazed solar hot water systems should be installed to "drainback" to a storage tank whenever solar radiation is insufficient. There are no thermal shock concerns with unglazed systems. Commonly used in swimming pool heating since solar energy's early beginnings, unglazed solar collectors heat swimming pool water directly without

15972-431: The westernmost known land in the world. Ancient European geographers such as Ptolemy recognised the island as the prime meridian of longitude. That remained so until the 19th century, when it was displaced by the one passing through Greenwich . Fuerteventura, with a surface of 1,660 km (640 sq mi), is the second largest island of the archipelago. It has been declared a biosphere reserve by UNESCO . It

16104-616: The world. This technology was originally used primarily in industrial applications such as manufacturing and assembly plants where there were high ventilation requirements, stratified ceiling heat, and often negative pressure in the building. With the increasing drive to install renewable energy systems on buildings, transpired solar collectors are now used across the entire building stock because of high energy production (up to 750 peak thermal Watts/square metre), high solar conversion (up to 90%) and lower capital costs when compared against solar photovoltaic and solar water heating. Solar air heating

16236-422: The year. Unglazed flat plate collectors are the preferred devices for heating swimming pool water. Unglazed collectors may be suitable in tropical or subtropical environments if domestic hot water needs to be heated by less than 20 °C (36 °F) over ambient temperature. Evacuated tube collectors have less aerodynamic drag, which may allow for a simpler installation on roofs in windy locations. The gaps between

16368-680: Was developed at CERN , while TVP SOLAR SA of Switzerland was the first company to commercialise Solar Keymark certified collectors in 2012. Evacuated flat plate solar collectors require both a glass-metal seal to join the glass plate to the rest of the metal envelope and an internal structure to support such plate against atmospheric pressure. The absorber has to be segmented or provided with suitable holes to accommodate such structure. Joining of all parts has to be high vacuum-tight and only materials with low vapour pressure can be used to prevent outgassing . Glass-metal seal technology can be based either on metallized glass or vitrified metal and defines

16500-593: Was developed from an earlier test of a 3.5-metre (11 ft) bowl in 1979–1982 by the Tata Energy Research Institute . That test showed the use of the solar bowl in the production of steam for cooking. The full-scale project to build a solar bowl and kitchen ran from 1996 and was fully operational by 2001. In locations with average available solar energy, flat plate collectors are sized approximately 1.2 to 2.4 square decimeter per liter of one day's hot water use. The main use of this technology

16632-554: Was formed by the Canary hotspot. The island is part of the Chinijo Archipelago and the Chinijo Archipelago Natural Park (Parque Natural del Archipiélago Chinijo). It is administered by the municipality of Teguise. In 2018, La Graciosa was declared as the eighth Canary Island by the Spanish Senate , though it is not recognized as such by the Canarian administration. It is administratively dependent on

16764-435: Was installed in 2000 on the coast of Al-Aryam Island , Abu Dhabi, United Arab Emirates. The design is a light steel structure, similar to a multi-span polytunnel, which relies purely on solar energy. A pipe array is installed to improve the design of the greenhouse by decreasing the temperature and increasing the freshwater production. The greenhouse has an area of 864 m and has a daily water production of 1 m, which nearly meets

16896-402: Was it politically, since the particular interests of the nobility (determined to strengthen their economic and political power through the acquisition of the islands) conflicted with those of the states, particularly Castile, which were in the midst of territorial expansion and in a process of strengthening of the crown against the nobility. Historians distinguish two periods in the conquest of

17028-611: Was ordered by decree that the capital of the Canary Islands would be shared between two cities, and this arrangement persists to the present day. The third largest city in the Canary Islands is San Cristóbal de La Laguna , another World Heritage Site on Tenerife. During the Age of Sail , the islands were the main stopover for Spanish galleons during the Spanish colonisation of the Americas , which sailed that far south in order to catch

17160-446: Was passed on via the female line. Social status and wealth were hereditary and determined the individual's position in the social pyramid, which consisted of the king, the relatives of the king, the lower nobility, villeins, plebeians, and finally executioners, butchers, embalmers, and prisoners". Their religion was animist , centring on the sun and moon, as well as natural features such as mountains. The islands may have been visited by

17292-501: Was patented by William H. Goettl and called the " Solar heat collector and radiator for building roof ". Evacuated flat-plate solar collectors are a more recent innovation and can be used for Solar Heat for Industrial Cooling (SHIC) and Solar Air Conditioning (SAC), where temperature in excess of 100 °C (212 °F) are required. These non-concentrating collectors harvest both diffuse and direct light and can make use of steam instead of water as fluid. Flat-plate collectors are

17424-405: Was the importance of the shade-net which is modelled by a thin film in the study shown in Figure 5. It not only provides cooling, but also elongates the cooling plume by containing the cold air plume from the evaporative cooling pad. Canary Island The Canary Islands ( / k ə ˈ n ɛər i / , Spanish : Canarias , Spanish: [kaˈnaɾjas] ), also known informally as

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