Go Solar Power For Homes Glossary of Terms – R – Z

Posted on 2009 under Glossary of Terms | No Comment

15 Mar

Rated power = Nominal power output of an inverter; not all units can produce rated power continuously.

Rectifier = Converts AC to DC electric current, as in a battery charger or converter.

Remote systems = Off-grid energy systems.

Resistive voltage drop = The voltage developed across a cell by the current flow through the resistance of the cell.

Reverse bias = Condition where the current producing capability of a PV cell is significantly less than that of other cells in its series string. This can occur when a cell is degraded (shaded, cracked etc) or when it is poorly matched electrically with other cells in its string.

S

Schottky barrier = A cell barrier that creates an interface between a semiconductor, such as silicon, and a sheet of metal.

Self discharge = The rate at which a battery will lose its charge.

Semiconductor = Uniquely suited to the photovoltaic conversion process, the semiconductor is a material that has a limited ability to conduct electric current between a metal and an insulator. Semiconductors used in different types of solar panels might include copper indium diselenide, cadmium telluride gallium arsenide, and silicon.

Semicrystalline = See ‘Multicrystalline.’

Series connection = A way of joining photovoltaic cells or batteries by connecting positive leads to negative leads; such a configuration increases the voltage.

Series regulator = Type of battery charge regulator where the charging current is controlled by a switch, transistor, or FET connected in series with the PV module or array.

Series resistance = Parasitic resistance to current flow in a cell due to mechanisms such as resistance from the bulk of the semiconductor material, metallic contacts, and interconnections.

Shelf life of batteries = The length of time, under pre-specified conditions, that a battery can be stored and still retain its stated capacity.

Short-circuit current (Isc) = Also known as the maximum current possible, this is the current flowing freely from a photovoltaic cell through an external circuit that has no load or resistance.

Silicon (Si) = This semi-metallic chemical element with atomic number 14, is an excellent semiconductor material. In nature it is dark gray and is a common constituent of sand and quartz. Silicon is by far the most common semiconductor material used in making photovoltaic devices and computer chips.

Single-crystal silicon = Silicon material with a single crystal structure, commonly used in the production of solar photovoltaic cells.

Solar constant = The strength of sunlight. The average amount of solar radiation that reaches the earth’s upper atmosphere, equal to 1353 watts per square meter in space and about 1000 watts per square meter at sea level at the equator at solar noon.

Solar energy/solar power = radiant energy that is generated by the sun – aka power obtained by harnessing the energy from the sun’s rays

Solar noon = the time of day when the sun reaches its highest point in the sky. This time divides the daylight hours for that day exactly in half. To determine solar noon, calculate the length of the day from the time of sunset and sunrise and divide by two. Solar noon may be quite a bit different from ‘clock’ noon.

Solar Panel = a panel designed to absorb the sun’s rays as a source of energy for generating electricity or heating.

Solar spectrum = The total distribution of electromagnetic radiation emanating from the sun.

Solar thermal electric = Method of producing electricity from solar energy by using focused sunlight to heat a working fluid, which in turn drives a turbo generator.

Stand alone = An autonomous or hybrid energy (also known as off-grid) a solar electric system that is not connected to a power grid. A battery bank is most likely used to store any unused daylight production for night time power. Often found in remote regions such as mountains, ocean platforms or communication towers.

State of charge (SOC) = The available capacity remaining in the battery, expressed as a percentage of the rated capacity.

Substrate = The physical material upon which a photovoltaic cell is made.

Sulfation = A condition that afflicts unused and discharged batteries; large crystals of lead sulfate grow on the plate, instead of the usual tiny crystals, making the battery extremely difficult to recharge.

Sun Tracker = Tracking system where the Solar Panels automatically adjust their position to best capture the solar energy at any time of day. Two axis tracking follows the suns elevation and azimuth in the sky so is superior.

Superstrate = The covering on the sun side of a PV module, providing protection for the PV materials from impact and environmental degradation while allowing maximum transmission of the appropriate wavelengths of the solar spectrum.

Thermal electric = Electric energy derived from heat energy, usually by heating a working fluid, which drives a turbo generator.

Thermophotovoltaic (TPV) device = A device that converts secondary thermal radiation, re-emitted by an absorber or heat source, into electricity.

Thick-crystalline materials = Cut from ribbons or ingots, this type of semiconductor material is usually about 200-400 microns thick.

Thin film = Commonly called amorphous film, this is a layer of semiconductor material, such as copper indium diselenide, cadmium telluride, gallium arsenide, or amorphous silicon, a few microns or less in thickness, used to make photovoltaic cells.

Thin film panel = It is a solar photovoltaic module that has been constructed with sequential layers of thin film semiconductor materials usually only micrometers thick. Currently, thin-film technologies account for around 12 percent of all solar modules sold worldwide. This share is expected to increase, since thin-film technologies offer less costs through less materials used. A solar panel that is thin and flexible. The term can refer to either amorphous photovoltaic solar panels, which use silicon as their semiconductor, or panels that use other semiconductors like cadmium telluride and copper indium gallium diselenide.

Tilt = the angle a solar panel makes against the horizon. The ideal tilt for a location will mean that the panels absorb as much sunlight as possible.

Tilt angle = The angle of inclination of a module measured from the horizontal.

Total internal reflection = The trapping of light by refraction and reflection at critical angles inside a semiconductor device so that it cannot escape the device and must eventually be absorbed by the semiconductor.

Tracking array = A PV array that follows the path of the sun to maximize the solar radiation landing on the PV surface. The two most common orientations are (1) one axis where the array tracks the sun east to west and (2) two-axis tracking where the array points directly at the sun at all times. Tracking arrays use both the direct and diffuse sunlight. Two-axis tracking arrays capture the maximum possible daily energy. Typically, a single axis tracker will give you 15% to 25% more power per day, and dual axis tracking will add about 5% to that. These results depend on the time of the year and the array location’s latitude.

Tracking panels = solar panels that can change the direction they face to follow the sun’s movements.

Transformer = Steps AC voltage up or down, depending on the application.

Trickle charge = A charge at a low rate, balancing through self-discharge losses, to maintain a cell or battery in a fully charged condition.

Two-axis tracking = A system capable of rotating independently about two axes (e.g., vertical and horizontal) and following the sun for maximum efficiency of the solar array.

Utility-interactive inverter = An inverter that only functions when connected to the grid. It uses the prevailing line-voltage frequency on the utility line as a control parameter to ensure that the PV system’s output is fully synchronized with the utility power.

VAC = AC electrical volts

VDC = DC electrical volts

Voc = Term for open-circuit voltage

Volt (V) = A unit of measure of the force, or ‘push,’ given to the electrons in an electric circuit. One volt produces one ampere of current when acting on a resistance of one ohm.

Vmp – aka voltage at maximum power = The voltage at which maximum power is available from a module.

Wafer = A thin sheet of semiconductor material made by mechanically sawing it from a single-crystal or multi-crystal ingot or casting.

Watt (W) = The unit of electric power equal to amps times volts, or amount of work (J) done in a unit of time. One ampere of current flowing at a potential of one volt produces one watt of power.

Watt-hour (Wh) = A unit of energy equal to one watt of power being used for one hour. See ‘Kilowatt-hour.

Waveform = The shape of the curve graphically representing the change in the ac signal voltage and current amplitude, with respect to time.

X,Y,Z

There are no terms in the glossary starting with X, Y or Z. This therefore is the end of the GSolarPowerForHomesDotCom Glossary of Terms. Hope you continue to find it useful for many years.

Sam Deane,
your solar power for homes guide,
at www dot go solar power for homes dot com

Visit Our
Homes & Gardens Solar Store!

Don’t forget to subscribe to our RSS Feed!

Info via: solar4power.com, homesolarpowersystems.org, sunwize.com and sunrunhome.com

Pic via: stock.xchng

This Trackback by Sam Deane, unless otherwise expressly stated, is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 United States License.