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)

movistor
Metal Oxide Varistor.

Used to protect electronic circuits from surge currents such as those produced by lightning.

multicrystalline
A semiconductor (photovoltaic) material composed of variously oriented, small, individual crystals. Sometimes referred to as polycrystalline or semicrystalline.
multijunction device
A high-efficiency photovoltaic device containing two or more cell junctions, each of which is optimized for a particular part of the solar spectrum.
multi-stage controlle, multistage controlle
A charging controller unit that allows different charging currents as the battery nears full state-of-charge.
National Electrical Code; NEC
Contains guidelines for all types of electrical installations.

The 1984 and later editions of the NEC contain Article 690, "Solar Photovoltaic Systems" which should be followed when installing a PV system.

National Electrical Manufacturers Association; NEMA
This organization sets standards for some non-electronic products like junction boxes.
nickel cadmium battery
A battery containing nickel and cadmium plates and an alkaline electrolyte.
nominal voltage
A reference voltage used to describe batteries, modules, or systems (such as, a 12-volt or 24-volt battery, module, or system).
normal operating cell temperature; NOCT
The estimated temperature of a photovoltaic module when operating under 800 watts per square meter irradiance, 20 degrees Celsius ambient temperature and wind speed of one meter per second.

NOCT is used to estimate the nominal operating temperature of a module in its working environment.

N-type semiconductor
A semiconductor produced by doping an intrinsic semiconductor with an electron-donor impurity (for example, phosphorus in silicon).
N-type silicon
Silicon material that has been doped with a material that has more electrons in its atomic structure than silicon.
N-type, N-type layer, N-type semiconductor, N-type silicon
1. A semiconductor to which an impurity has been added so the concentration of electrons is much higher than the concentration of holes; the electrical current is carried chiefly by these electrons.
2. Negative semiconductor material in which there are more electrons than holes; current is carried through it by the flow of electrons.
ohm
A measure of the electrical resistance of a material equal to the resistance of a circuit in which the potential difference of one volt produces a current of one ampere.
one-axis tracking
A system capable of rotating about one axis.
open-circuit voltage; Voc
The maximum possible voltage across a photovoltaic cell; the voltage across the cell in sunlight when no current is flowing.
—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.