1. Relating to or derived from the sun or utilizing the energies of the sun.
2. Referring to, or proceeding from the sun; such as, "solar rays" and "solar physics".
3. Using or operated by energy derived from the sun; including "a solar heating system".
4. Determined or measured in reference to the sun, as the "solar year".
5. Describing any renewable form of energy that does not create greenhouse gas emissions or nondegradable toxic wastes.

A solar pond that consists of three main layers; the top one is near ambient temperature and has low salt content, while the bottom one is very hot and salty and is lined with a dark-colored material.

The middle (gradient) zone acts as a transparent insulator, permitting sunlight to be trapped in the bottom layer (from which useful heat is withdrawn).

This middle layer, which increases in brine density with depth, counteracts the tendency of the warmer water below to rise to the surface and lose heat in the air.

A term for variations in the appearance or energy output of the sun; usually associated with the variation of sunspots and other features over the eleven-year solar cycle.

A type of solar thermal system in which air is heated in a collector and either transferred directly to the interior space or to a storage medium.

The conception, design, and construction of buildings and communities so as to make optimal use of incoming solar radiation, as for heating and cooling, or power generation.

The horizontal angle between the sun and due south in the Northern Hemisphere, or between the sun and due north in the Southern Hemisphere.

A sudden, transient enhancement of nonthermal radio emission from the solar corona, usually associated with an active region or flare.

A well-insulated enclosure with a small opening to let in concentrated solar energy, approaching a blackbody absorber in its ability to capture solar energy.

Black body or blackbody is a theoretical object that is simultaneously a perfect absorber and emitter of radiant energy; that is, it absorbs all the radiation striking it and reflects no radiation, and whose energy distribution is dependent only on its temperature.

Any material that converts sunlight directly into electricity.

This property of materials is known as the photoelectric effect, first described in 1905 by albert Einstein in his Nobel prize-winning research.

Here on earth, silicon solar cells have brought abundant clean water, electricity, and telephone services to many in remote regions who had hitherto done without.

A solar-powered airplane that in 1981 flew across the English Channel in 5 hours and 23 minutes.

The plane had 16,000 solar cells mounted on the wings that generated 3,000 watts of power.

A power generating facility that converts solar radiation into the kinetic energy of moving air, which is then transformed into electricity by a turbine.

A collector is covered by a transparent glazing that heats up the air mass inside it; buoyancy then drives the warmer air into the chimney, where it drives a turbine.

1. A term for a city that obtains a significant amount of its total energy needs from solar energy and other renewable resources.
2. Solar City is an international cooperative program to encourage cities and urban regions to substitute renewable and sustainable forms of energy technology for conventional sources, with the long-term goal of achieving globally acceptable greenhouse gas emission levels and lower reliance on fossil fuels.

A flat black paint or another highly absorptive substance that is applied to the absorber plate of a solar collector.

The total radiant energy received vertically from the sun, per unit area per unit of time, at a position just outside the earth's atmosphere when the earth is at its average distance from the sun.

Any of various devices that convert radiant energy from the sun into thermal energy for cooking, water purification, and other household uses.

A typical version is a concave bowl-shaped dish with an inner surface that is made of reflective material; sunlight falling on the inner surface is focused onto a dark cooking pot that is hung or set in front of the cooker.

The use of the sun's radiant energy to cool a living space, by various means; such as, a pond of water on a flat roof that cools via evaporation (passive cooling), or the use of solar energy to power a cooling appliance (active cooling).

The main periodic cycle in the sun's activity that occurs over about an eleven-year period.

The period is not constant, varying between about 9.5 and 12.5 years.

During the cycle, changes occur in the sun's internal magnetic field and in its surface disturbance level.

1. A day defined as one complete rotation of the earth on its axis in relation to the sun.
2. The twenty-four-hour period between two successive transits of the sun across a given meridian on earth.

The apparent angle of the sun either north or south of the earth's equatorial plane.

The earth's rotation on its axis causes a daily change in solar declination.

A deterioration of materials which is produced by their exposures to solar energy.

The conversion of brackish water, or salt water, to useful fresh water by direct utilization of solar energy; such as, a "solar still".

The use of chemical reactions driven by solar radiation to break down contaminant molecules in the air or the water; that is, the detoxification of water through thermal chemical reactions driven by the heat generated by concentrating solar collectors.

A system that uses a mirrored dish to collect and concentrate solar radiation onto a receiver, which absorbs the heat and transfers it to a fluid within an engine.

The heat causes the fluid to expand against a piston or a turbine to produce mechanical power, which in turn can be used to run a generator or an alternator to produce electricity.

A technology employed to improve the quality of drinking water, by the use of solar radiation to destroy pathogenic micro-organisms that can cause water-borne diseases.

A technology employed to purify water by means of solar energy; for example, a solar collector is used to heat water, which evaporates and then condenses.

As the water evaporates, only the water vapor rises, leaving contaminants behind.

An economy based on the use of solar power; as well as, other renewable forms of energy that replace the use of fossil fuels.

A method of producing electricity from solar energy by using focused sunlight to heat a working fluid, which in turn drives a turbo-generator.

A statement of the amount of energy received from the sun in terms of some conventional energy unit; such as, kilowatt-hours, barrels of oil, tons of coal, etc.; used to describe the relative ability of solar energy to fulfill contemporary energy requirements as compared to fossil fuel sources.

1. Useful energy that is immediately derived from the sun; for example, a system that collects and uses the heat of the sun to warm a building or to generate electricity.
2. In the larger sense, any energy source that can be ultimately traced to the action of the sun.

A general term for any power source that is driven by solar energy; such as, a system of solar panels used to power an electric propulsion system.

A surface or feature of a building that is specifically designed and built to gain solar energy for heat and power; such as through the use of silicon solar panels.

A window glazing coating, usually tinted gray or bronze, used to reduce building cooling loads, glare, and fabric fading.

A region of exceptionally high temperature and brightness that suddenly develops in the solar chromosphere near a sunspot. It is often associated with magnetic field activities.

1. A term for the use of "solar energy" rather than a "conventional fuel" as an energy source; for example, to produce electricity.
2. The use of a solar energy system to provide high-temperature process heat for the production of storable and transportable fuels; such as, the production of hydrogen from the thermal dissociation of water.

A large-scale solar collector that is capable of creating highly concentrated solar energy (typically by means of an array of large curved mirrors) in order to produce extremely high temperatures at a localized site; such as, the Odello solar furnace (the world's largest solar furnace located in the eastern Pyrenees region of France).

It generates temperature in the range of 800-2500 degrees centigrade, and is used for research on solar materials and solar energy conversion.

The amount of energy that a building absorbs due to solar energy striking its exterior and conducting to the interior, or by passing through windows and being absorbed by materials in the building.

A stand-alone electrical power supply system for single buildings by means of solar energy, typically used to operate small appliances in rural areas without electrification.

The use of solar thermal technologies to produce hot air, water, or steam for industrial purposes, generally at temperatures below 250 degrees centigrade.

The fulgent power output of the sun or any other star: Tom and the other astronomers used highly technical telescopes to study the changes or variations of the solar luminosity during the phases of the calendar year.

The precise moment of the day that divides the daylight hours for that day exactly in half.

The local time of day when the sun crosses the observer's meridian.

1. Solar One was an early solar power plant operating from 1982 to 1986 in Barstow, California.

It was composed of a solar receiver located on top of a tower surrounded by a field of reflectors.

2. Solar Two uses advanced molten-salt technology to overcome energy storage problems that lowered the efficiency of Solar One.

An individual unit in a solar collector; such as, a device that collects solar energy from incident radiation.

Typically a sun-oriented box with a transparent cover, containing water tubes or air baffles under a blackened heat-absorbent pane.

A solar energy device having a parabola-shaped (curve formed) reflector (trough) that focuses the sun's direct beam radiation onto a linear receiver located at the focus of the parabola.

A heat transfer fluid is heated as it circulates through the receiver, with the captured energy used to generate steam for power generation or for process heat.

A small artificial lake used to collect solar energy, which can then be removed from the pond in the form of useful heat, or an external heat exchanger, or a heat exchanger placed on the bottom of the pond, which converts the thermal energy into electricity.

A proposed system to supply power from space for use on the earth.

The SPS system, or solar power satellite system, would have a huge array of solar cells that would generate electrical power to be beamed to earth in the form of microwave energy sent to a central receiver.

An energy conversion system that uses a large field of independently adjustable mirrors (heliostats) to focus solar rays on a near single point on the top of a fixed tower (receiver).

The use of solar energy to partially heat a substance; such as, domestic drinking water, prior to heating it to a higher desired temperature with conventional fuel.

All the constituents that make up the total electromagnetic radiation emitted y the sun; about 99 percent of solar radiation is contained in a wavelength region from about 300 nanometers (ultraviolet) to 3,000 nanometers (near-infrared).

The amount of solar insolation that a given site receives, usually measured in kilowatt hours per square meter per day.

A device used to desalinate or distill water by means of solar energy; that is, sunlight heats the water within a receptacle (still) by means of a greenhouse effect.

A large-scale solar flare that affects the earth's magnetic field.

The conversion of the radiant energy from the sun into heat, which can then be used for such purposes as space and hot water heating, industrial process heat, or power generation.

Solar thermal energy can be used for such applications as, space heating, air conditioning, hot water, industrial process heat, drying, distillation and desalination, and electrical power.

The vertical movement of water due to gravitational attraction between the sun and the earth.

The solar tide generating force is only about three-sevenths of the lunar tide, due to the closer distance of the moon to the earth.

1. Local time as measured by an instrument; such as, a sundial.
2. A system of measurement based on the position of the earth in relation to the sun.

An economy in which direct solar energy would be the primary energy source and hydrogen the secondary energy carrier.

Power from wind or photovoltaic systems would drive photo-electrolytic hydrogen production.