A solar furnace is a structure that uses

concentrated solar power Concentrated solar power (CSP, also known as concentrating solar power, concentrated solar thermal) systems generate solar power by using mirrors or lenses to concentrate a large area of sunlight into a receiver. Electricity is generated when ...

to produce high temperatures, usually for industry.

Parabolic mirror A parabolic (or paraboloid or paraboloidal) reflector (or dish or mirror) is a reflective surface used to collect or project energy such as light, sound, or radio waves. Its shape is part of a circular paraboloid, that is, the surface generated ...

s or

heliostat A heliostat (from ''helios'', the Greek word for ''sun'', and ''stat'', as in stationary) is a device that includes a mirror, usually a plane mirror, which turns so as to keep reflecting sunlight toward a predetermined target, compensating ...

s concentrate

light Light or visible light is electromagnetic radiation that can be perceived by the human eye. Visible light is usually defined as having wavelengths in the range of 400–700 nanometres (nm), corresponding to frequencies of 750–420 tera ...

(

Insolation Solar irradiance is the power per unit area (surface power density) received from the Sun in the form of electromagnetic radiation in the wavelength range of the measuring instrument. Solar irradiance is measured in watts per square metre (W/m ...

) onto a focal point. The temperature at the focal point may reach , and this heat can be used to generate

electricity Electricity is the set of physical phenomena associated with the presence and motion of matter that has a property of electric charge. Electricity is related to magnetism, both being part of the phenomenon of electromagnetism, as described ...

, melt

steel Steel is an alloy made up of iron with added carbon to improve its strength and fracture resistance compared to other forms of iron. Many other elements may be present or added. Stainless steels that are corrosion- and oxidation-resistant ty ...

, make

hydrogen fuel Hydrogen fuel refers to hydrogen which is burned as fuel with oxygen. It is zero-carbon, provided that it is created in a process that does not involve carbon. It can be used in fuel cells or internal combustion engines (see HICEV). Regarding hydr ...

nanomaterials * Nanomaterials describe, in principle, materials of which a single unit is sized (in at least one dimension) between 1 and 100 nm (the usual definition of nanoscale). Nanomaterials research takes a materials science-based approach to nan ...

. The largest solar furnace is at

Odeillo Font-Romeu-Odeillo-Via (; ca, Font-romeu, Odelló i Vià), or simply Odeillo, is a commune in the Pyrénées-Orientales and Cerdagne near the Spanish border in the south of France. It comprises the villages of Odeillo and Via, as well as Font-Ro ...

in the

Pyrénées-Orientales Pyrénées-Orientales (; ca, Pirineus Orientals ; oc, Pirenèus Orientals ; ), also known as Northern Catalonia, is a department of the region of Occitania, Southern France, adjacent to the northern Spanish frontier and the Mediterranean Sea. ...

France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of Overseas France, overseas regions and territories in the Americas and the Atlantic Ocean, Atlantic, Pacific Ocean, Pac ...

, opened in 1970. It employs an array of plane mirrors to gather sunlight, reflecting it onto a larger curved mirror.

History

The

ancient Greek Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic peri ...

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...

term ''heliocaminus'' literally means "solar furnace" and refers to a

glass Glass is a non-crystalline, often transparent, amorphous solid that has widespread practical, technological, and decorative use in, for example, window panes, tableware, and optics. Glass is most often formed by rapid cooling (quenching) of ...

-enclosed

sunroom A sunroom, also frequently called a solarium (and sometimes a "Florida room", "garden conservatory", "garden room", "patio room", "sun parlor", "sun porch", "three season room" or "winter garden"), is a room that permits abundant daylight and v ...

intentionally designed to become hotter than the outside air temperature. During the

Second Punic War The Second Punic War (218 to 201 BC) was the second of three wars fought between Carthage and Rome, the two main powers of the western Mediterranean in the 3rd century BC. For 17 years the two states struggled for supremacy, primarily in Ital ...

(218–202 BC), the

Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...

scientist A scientist is a person who conducts Scientific method, scientific research to advance knowledge in an Branches of science, area of the natural sciences. In classical antiquity, there was no real ancient analog of a modern scientist. Instead, ...

Archimedes Archimedes of Syracuse (;; ) was a Greek mathematician, physicist, engineer, astronomer, and inventor from the ancient city of Syracuse in Sicily. Although few details of his life are known, he is regarded as one of the leading scientists ...

is said to have repelled the attacking

Roman Roman or Romans most often refers to: *Rome, the capital city of Italy *Ancient Rome, Roman civilization from 8th century BC to 5th century AD *Roman people, the people of ancient Rome *''Epistle to the Romans'', shortened to ''Romans'', a letter ...

ships by setting them on fire with a " burning glass" that may have been an array of mirrors. There have been several real-world tests to evaluate the validity of this myth over the centuries, including a test by

Comte de Buffon Georges-Louis Leclerc, Comte de Buffon (; 7 September 1707 – 16 April 1788) was a French naturalist, mathematician, cosmologist, and encyclopédiste. His works influenced the next two generations of naturalists, including two prominent F ...

(circa 1747), documented in the paper titled "Invention De Miroirs Ardens, Pour Brusler a Une Grande Distance", and an experiment by John Scott, which was documented in an 1867 paper.Greek scientist Dr. Ioannis Sakkas, curious about whether Archimedes could really have used a "burning glass" to destroy the Roman fleet in 212 BC, lined up nearly 60 Greek sailors, each holding an oblong mirror tipped to catch the sun’s rays and direct them at a wooden ship 160 feet away. The ship caught fire at once. Sakkas said after the experiment there was no doubt in his mind the great inventor could have used bronze mirrors to scuttle the Romans. However, accounting for battle conditions makes such a weapon impractical, with modern tests refuting such claims. An experiment was carried out by a group at the

Massachusetts Institute of Technology The Massachusetts Institute of Technology (MIT) is a private land-grant research university in Cambridge, Massachusetts. Established in 1861, MIT has played a key role in the development of modern technology and science, and is one of the ...

in 2005. It concluded that although the theory was sound for stationary objects, the mirrors would not likely have been able to concentrate sufficient

solar energy Solar energy is radiant light and heat from the Sun that is harnessed using a range of technologies such as solar power to generate electricity, solar thermal energy (including solar water heating), and solar architecture. It is an essenti ...

to set a ship on fire under battle conditions. Similar experiments were conducted on the popular science-based TV show ''

MythBusters ''MythBusters'' is a science entertainment television program, developed by Peter Rees and produced by Australia's Beyond Television Productions. The series premiered on the Discovery Channel on January 23, 2003. It was broadcast internatio ...

'' in

2004 2004 was designated as an International Year of Rice by the United Nations, and the International Year to Commemorate the Struggle Against Slavery and its Abolition (by UNESCO). Events January * January 3 – Flash Airlines Flight 6 ...

2006 File:2006 Events Collage V1.png, From top left, clockwise: The 2006 Winter Olympics open in Turin; Twitter is founded and launched by Jack Dorsey; The Nintendo Wii is released; Montenegro 2006 Montenegrin independence referendum, votes to declare ...

, and

2010 File:2010 Events Collage New.png, From top left, clockwise: The 2010 Chile earthquake was one of the strongest recorded in history; The Eruption of Eyjafjallajökull in Iceland disrupts air travel in Europe; A scene from the opening ceremony of ...

, arriving at similar results based on the premise of the controversial myth. However, an episode of '' Richard Hammond's Engineering Connections'' relating to the

Keck Observatory The W. M. Keck Observatory is an astronomical observatory with two telescopes at an elevation of 4,145 meters (13,600 ft) near the summit of Mauna Kea in the U.S. state of Hawaii. Both telescopes have aperture primary mirrors, and when comp ...

(whose reflector glass is based on the Archimedes' Mirror) did successfully use a much smaller curved mirror to burn a wooden model, although the scaled-down model was not made of the same quality of materials as in the ''MythBusters'' effort. The first modern solar furnace is believed to have been built in France in 1949 by Professor Félix Trombe. The device, the

Mont-Louis Solar Furnace The Mont-Louis Solar Furnace is an experimental solar furnace - a solar thermal energy facility that was built in 1949. It was the first facility of its kind in the world, and was a precursor of the Odeillo Solar Furnace. It provides a thermal p ...

is still in place at Mont-Louis. The Pyrenees were chosen as the site because the area experiences clear skies up to 300 days a year. The

Odeillo Solar Furnace The Odeillo solar furnace is the world's largest solar furnace. It is situated in Font-Romeu-Odeillo-Via, in the department of Pyrénées-Orientales, in the south of France. It is high and wide, and includes 63 heliostats. It was built between 1 ...

is a larger and more powerful solar furnace. It was built between 1962 and 1968, and started operating in 1969. It's currently the most powerful, based on an achievable temperature of 3500 °C. The Solar Furnace of Uzbekistan was built in Uzbekistan and opened in 1981 as a part of a Soviet Union "Sun" Complex Research Facility, being the world largest concentrator.

Uses

The rays are focused onto an area the size of a cooking pot and can reach , depending on the process installed, for example: * about for metallic receivers producing hot air for the next generation solar towers as it will be tested at the Themis plant with the Pegase project * about to produce hydrogen by cracking methane molecules * up to to test materials for extreme environment such as nuclear reactors or space vehicle atmospheric reentry * up to to produce

by solar induced sublimation and controlled cooling, such as

carbon nanotube A scanning tunneling microscopy image of a single-walled carbon nanotube Rotating single-walled zigzag carbon nanotube A carbon nanotube (CNT) is a tube made of carbon with diameters typically measured in nanometers. ''Single-wall carbon na ...

s or zinc nanoparticles It has been suggested that solar furnaces could be used in

space Space is the boundless three-dimensional extent in which objects and events have relative position and direction. In classical physics, physical space is often conceived in three linear dimensions, although modern physicists usually consider ...

to provide energy for manufacturing purposes. Their reliance on sunny weather is a limiting factor as a source of

renewable energy Renewable energy is energy that is collected from renewable resources that are naturally replenished on a human timescale. It includes sources such as sunlight, wind, the movement of water, and geothermal heat. Although most renewable energy ...

Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surfa ...

but could be tied to

thermal energy storage Thermal energy storage (TES) is achieved with widely different technologies. Depending on the specific technology, it allows excess thermal energy to be stored and used hours, days, months later, at scales ranging from the individual process, ...

systems for energy production through these periods and into the night.

Smaller-scale devices

The solar furnace principle is being used to make inexpensive

solar cooker A solar cooker is a device which uses the energy of direct sunlight to heat, cook or pasteurize drink and other food materials. Many solar cookers currently in use are relatively inexpensive, low-tech devices, although some are as powerful or as ...

s and solar-powered

barbecue Barbecue or barbeque (informally BBQ in the UK, US, and Canada, barbie in Australia and braai in South Africa) is a term used with significant regional and national variations to describe various cooking methods that use live fire and smoke t ...

s, and for solar water

pasteurization Pasteurization or pasteurisation is a process of food preservation in which packaged and non-packaged foods (such as milk and fruit juices) are treated with mild heat, usually to less than , to eliminate pathogens and extend shelf life. The ...

. A prototype Scheffler reflector is being constructed in

India India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...

for use in a solar

crematorium A crematorium or crematory is a venue for the cremation of the dead. Modern crematoria contain at least one cremator (also known as a crematory, retort or cremation chamber), a purpose-built furnace. In some countries a crematorium can also be ...

. This 50 m² reflector will generate temperatures of and displace 200–300 kg of firewood used per cremation.

References

External links

Article about the Odeillo and Mont Louis solar furnacesHochflussdichte Sonnenofen des DLR, KölnBBC News article about the solar power station serving Seville, Spain
{{Solar energy Industrial furnaces Solar thermal energy Heaters

History

Uses

Smaller-scale devices

See also

References

External links