Photovoltaic Conversion Efficiency Terms +

(solar electricity technical terms applying to electricity, power generation, concentrating solar power, or CSP, solar heating, solar lighting, and solar electricity)

shunt regulator
Type of a battery charge regulator where the charging current is controlled by a switch connected in parallel with the photovoltaic (PV) generator.

Shorting the photovoltaic generator prevents overcharging of the battery.

siemen
A unit of measurement for electric conductance, equal to the conductance at which a potential of one volt forces a current of one ampere; the inverse of the ohm.
siemens process
A commercial method of making purified silicon.
Siemens, Werner von
A German inventor (1816-1892) and industrialist who made notable advances in electrical engineering; such as, the discovery of the dynamoelectric principle (which was an improved electric train) and who also co-founded what would become a leading electronics and communication company which is still in operation.
silicon; Si
A semi-metallic chemical element that makes an excellent semiconductor material for photovoltaic devices.

It crystallizes in face-centered cubic lattice like a diamond. It's commonly found in sand and quartz (as the oxide).

stand-alone system, remote system
An autonomous or hybrid photovoltaic system not connected to a grid.

It may, or may not, have storage; but most stand-alone systems require batteries or some other form of storage.

standard reporting conditions; SRC
A fixed set of conditions (including meteorological) to which the electrical performance data of a photovoltaic module are translated from the set of actual test conditions.
standard test conditions; STC
Conditions under which a module is typically tested in a laboratory.
standby current
This is the amount of current (power) used by the inverter when no load is active (lost power).

The efficiency of the inverter is lowest when the load demand is low.

stand-off mounting
Technique for mounting a photovoltaic array on a sloped roof, which involves mounting the modules a short distance above the pitched roof and tilting them to the optimum angle.
starved electrolyte cell
A battery containing little or no free fluid electrolyte.
state-of-charge; SOC
The available capacity remaining in the battery, expressed as a percentage of the rated capacity.
storage battery
A device capable of transforming energy from electric to chemical form and vice versa.

The reactions are almost completely reversible. During discharge, chemical energy is converted to electric energy and is consumed in an external circuit or apparatus.

stratification
A condition that occurs when the acid concentration varies from top to bottom in the battery electrolyte.

Periodic, controlled charging at voltages that produce gassing will mix the electrolyte.

string
A number of photovoltaic modules or panels interconnected electrically in series to produce the operating voltage required by the load.
—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.