astronomy

Solar furnace

Solar furnace is a astronomy topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Solar furnace rather than just read about it. In short: A solar furnace is a structure that uses concentrated solar power to produce high temperatures, usually for industry. Parabolic mirrors or heliostats concentrate light (Insolation) onto a focal point.

Key takeaways

Solar furnace belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Solar furnace to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Solar furnace from memory before moving on to harder problems.

Reference excerpt

A solar furnace is a structure that uses concentrated solar power to produce high temperatures, usually for industry. Parabolic mirrors or heliostats concentrate light (Insolation) onto a focal point. The temperature at the focal point may reach 3,500 °C (6,330 °F), and this heat can be used to generate electricity, melt steel, make hydrogen fuel or nanomaterials. The largest solar furnace is at Odeillo in the Pyrénées-Orientales in France, opened in 1970. It employs an array of plane mirrors to gather sunlight, reflecting it onto a larger curved mirror.

History The ancient Greek / Latin term heliocaminus means "solar furnace" and refers to a glass-enclosed sunroom intentionally designed to become hotter than the outside air temperature. Legendary accounts of the Siege of Syracuse (213–212 BC) tell of Archimedes' heat ray, a set of burnished brass mirrors or burning glasses supposedly used to ignite attacking ships, though modern historians doubt its veracity. On 24 September 1901, Knut C. Wideen was granted a patent for a "System for collecting and utilizing solar heat", which included a solar furnace. 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 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 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 4,000 °C (7,230 °F), depending on the process installed; for example:

about 1,000 °C (1,830 °F) 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 1,400 °C (2,550 °F) to produce hydrogen by cracking methane molecules up to 2,500 °C (4,530 °F) to test materials for extreme environment such as nuclear reactors or space vehicle atmospheric reentry up to 3,500 °C (6,330 °F) to produce nanomaterials by solar induced sublimation and controlled cooling, such as carbon nanotubes or zinc nanoparticles It has been suggested that solar furnaces could be used in space to provide energy for manufacturing purposes. Their reliance on sunny weather is a limiting factor as a source of renewable energy on Earth but could be tied to thermal energy storage 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 cookers and solar-powered barbecues, and for solar water pasteurization. A prototype Scheffler reflector is being constructed in India for use in a solar crematorium. This 50 m2 reflector will generate temperatures of 700 °C (1,292 °F) and save 200–300 kg of firewood used per cremation.

See also Solar power tower Solar thermal energy Solar thermal collector Solar furnace of Uzbekistan

References

External links Article about the Odeillo and Mont Louis solar furnaces Hochflussdichte Sonnenofen des DLR, Köln Page including an animation of a solar furnace BBC News article about the solar power station serving Seville, Spain Build a solar furnace

Illustrations

Worked examples

Example 1 — a first encounter with Solar furnace

Start with the simplest possible case. Write down what Solar furnace claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In astronomy, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Solar furnace before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Solar furnace ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Solar furnace

In research: Solar furnace appears in astronomy research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Solar furnace in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Solar furnace is common in secondary-school and first-year university syllabi. It links to neighbouring topics Heaters, Industrial furnaces, Industrial processes, so understanding it makes those chapters shorter.
In everyday life: Look for Solar furnace outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Solar furnace in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Solar furnace means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Solar furnace out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Solar furnace in simple terms?

Why does Solar furnace matter?

Because it connects several astronomy ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Solar furnace?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Solar furnace.