Solar Glossary: [ A-B ] [C ] [ D-F ] [ G-H ] [ I-N ] [ O-P ] [ Q-R ] [ S ] [ T-Z ]
Solar Glossary S (part 3)
- Solar Thermal Parabolic Dishes
- A solar thermal technology that uses a modular mirror system that approximates a parabola and incorporates two-axis tracking to focus the sunlight onto receivers located at the focal point of each dish. The mirror system typically is made from a number of mirror facets, either glass or polymer mirror, or can consist of a single stretched membrane using a polymer mirror. The concentrated sunlight may be used directly by a Stirling, Rankine, or Brayton cycle heat engine at the focal point of the receiver or to heat a working fluid that is piped to a central engine. The primary applications include remote electrification, water pumping, and grid-connected generation.
- Solar Thermal Systems
- Solar energy systems that collect or absorb solar energy for useful purposes. Can be used to generate high temperature heat (for electricity production and/or process heat), medium temperature heat (for process and space/water heating and electricity generation), and low temperature heat (for water and space heating and cooling).
- Solar Time
- The period marked by successive crossing of the earth's meridian by the sun; the hour angle of the sun at a point of observance (apparent time) is corrected to true (solar) time by taking into account the variation in the earth's orbit and rate of rotation. Solar time and local standard time are usually different for any specific location.
- Solar Trough Systems (see also Parabolic Trough, above)
- A type of solar thermal system where sunlight is concentrated by a curved reflector onto a pipe containing a working fluid that can be used for process heat or to produce electricity. The world's largest solar thermal electric power plants use solar trough technology. They are located in California, and have a combined electricity generating capacity of 240,000 kilowatts.
- Solar Transmittance
- The amount of solar energy that passes through a glazing material, expressed as a percentage.
- Solar Two
- Solar Two is a retrofit of the Solar One project (see above). It is demonstrating the technical feasibility and power potential of a solar power tower using advanced molten-salt technology to store energy. Solar Two retains several of the main components of Solar One, including the receiver tower, turbine, generator, and the 1,818 heliostats.
- Solenoid
- An electromechanical device composed of a coil of wire wound around a cylinder containing a bar or plunger, that when a current is applied to the coil, the electromotive force causes the plunger to move; a series of coils or wires used to produce a magnetic field.
- Solenoid Valve
- An automatic valve that is opened or closed by an electromagnet.
- Solid Fuels
- Any fuel that is in solid form, such as wood, peat, lignite, coal, and manufactured fuels such as pulverized coal, coke, charcoal, briquettes, pellets, etc.
- Solidity
- In reference to a wind energy conversion device, the ratio of rotor blade surface area to the frontal, swept area that the rotor passes through.
- Solstice
- The two times of the year when the sun is apparently farthest north and south of the earth's equator; usually occurring on or around June 21 (summer solstice in northern hemisphere, winter solstice for southern hemisphere) and December 21 (winter solstice in northern hemisphere, summer solstice for the southern hemisphere).
- Spectrum
- see Solar Spectrum above.
- Spectrally Selective Coatings
- A type of window glazing films used to block the infrared (heat) portion of the solar spectrum but admit a higher portion of visible light.
- Stagnation Temperature
- A condition that can occur in a solar collector if the working fluid does not circulate when sun is shining on the collector.
- Sun Path Diagram
- A circular projection of the sky vault onto a flat diagram used to determine solar positions and shading effects of landscape features on a solar energy system.
About the list of terms on this page.
The U.S. Department of Energy Efficiency and Renewable Energy Home Page is a great starting point for learning about renewable energy methods and sources. To assist in educating consumers, the website provides calculators and guides of all kinds to assist the consumer in saving money, saving energy and making the most of the renewable energy sources available. The solar energy terms and definitions on our glossary pages were extracted from the extensive DOE EERE glossary of terms about all aspects and forms of energy.