rated module current
The current output of a photovoltaic module measured at standard test conditions of 1,000 w/m2 and 25 degrees Celsius cell temperature.
rated power
Rated power of the inverter; however, some units can not produce rated power continuously.
See duty rating for additional information.
reactive power
The sine of the phase angle between the current and voltage waveforms in an alternating current system.
See power factor for additional information.
recombination
The action of a free electron falling back into a hole.
Recombination processes are either radiative, where the energy of recombination results in the emission of a photon, or nonradiative, where the energy of recombination is given to a second electron which then relaxes back to its original energy by emitting phonons.
Recombination can take place in the bulk of the semiconductor, at the surfaces, in the junction region, at defects, or between interfaces.
rectifier
A device that converts alternating current to direct current.
regulator
Prevents overcharging of batteries by controlling charge cycle-usually adjustable to conform to specific battery needs.
reserve capacity
The amount of generating capacity a central power system must maintain to meet peak loads.
resistance
The property of a conductor, which opposes the flow of an electric current resulting in the generation of heat in the conducting material.
The measure of the resistance of a given conductor is the electromotive force needed for a unit current flow. The unit of resistance is ohms.
resistive voltage drop
The voltage developed across a cell by the current flow through the resistance of the cell.
reverse current protection
Any method of preventing unwanted current flow from the battery to the photovoltaic array (usually at night).
Also see blocking diode.
ribbon (photovoltaic) cells
A type of photovoltaic device made in a continuous process of pulling material from a molten bath of photovoltaic material; such as, silicon, to form a thin sheet of material.
root mean square; RMS
The square root of the average square of the instantaneous values of an ac output.
For a sine wave the root mean square value is 0.707 times the peak value. The equivalent value of alternating current, I, that will produce the same heating in a conductor with resistance, R, as a dc current of value I.
sacrificial anode, sacrificial metal, sacrificial protection
A piece of metal buried near a structure that is to be protected from corrosion.
The purposeful corrosion of a less desirable metal so that an adjacent preferred metal can be protected from corrosion.
satellite power system; SPS
Concept for providing large amounts of electricity for use on the earth from one or more satellites in geosynchronous earth orbit.
A very large array of solar cells on each satellite would provide electricity, which would be converted to microwave energy and beamed to a receiving antenna on the ground. There, it would be reconverted into electricity and distributed the same as any other centrally generated power, through a grid.
Schottky barrier
A cell barrier, or junction between a layer, established as the interface between a semiconductor; such as, silicon, and a sheet of metal characterized by hot carriers.
Named for the German physicist Walter Hans Schottky (1886-1976).
—The information for the entries in this unit were compiled primarily from data
provided in the following source:
"U.S. Department of Energy, Energy Efficiency and Renewable Energy"
consisting of definitions of many important terms having to do with electricity,
power generation, concentrating solar power (CSP), solar heating, solar lighting,
and solar electricity, also known as photovoltaic (PV).
Information was also compiled from the
Academic Press Dictionary of Science and Technology; Edited by Christopher Morris;
Academic Press; Harcourt Brace Jovanovich, Publishers; New York; 1992;
as well as,
McGraw-Hill Dictionary of Scientific and Technical Terms, 4th edition;
Sybil P. Parker, editor in chief; McGraw-Hill, Inc.; 1989.
Index of additional Scientific and Technological Topics.
