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)

intrinsic semiconductor
An undoped semiconductor.
inverter
A device that converts direct current electricity to alternating current either for stand-alone systems or to supply power to an electricity grid.
ion
An electrically charged atom, or group of atoms, that has lost or gained electrons.

A loss makes the resulting particle positively charged; a gain makes the particle negatively charged.

irradiance
The direct, diffuse, and reflected solar radiation that strikes a surface.

Usually expressed in kilowatts per square meter. Irradiance multiplied by time equals insolation.

ISPRA guidelines
Guidelines for the assessment of photovoltaic power plants, published by the Joint Research Center of the Commission of the European Communities, Ispra, Italy.
I-Type semiconductor
Semiconductor material that is left intrinsic, or undoped so that the concentration of charge carriers is characteristic of the material itself rather than of added impurities.
I-V curve
A graphical presentation of the current versus the voltage from a photovoltaic device as the load is increased from the short circuit (no load) condition to the open circuit (maximum voltage) condition.

The shape of the curve characterizes cell performance.

joule, J
1. A metric unit of energy or work; one joule per second equals one watt or 0.737 foot-pounds; one Btu equals 1,055 joules.
2. An SI unit of work and energy, replacing the calorie (one joule equals 4.2 calories).
junction
A region of transition between semiconductor layers; such as, a p/n junction, which goes from a region that has a high concentration of acceptors (p-type) to one that has a high concentration of donors (n-type).
junction box
A photovoltaic (PV) generator junction box is an enclosure on the module where PV strings are electrically connected and where protection devices can be located, if necessary.
junction diode
A semiconductor device with a junction and a built-in potential that passes current better in one direction than the other. All solar cells are junction diodes.
kilowatt; kW
A standard unit of electrical power equal to 1000 watts, or to the energy consumption at a rate of 1000 joules per second.
kilowatt-hour, kilowatt hour; kWh
A quantity of 1,000 thousand watts acting over a period of one hour.

The kWh is a unit of energy. One kWh=3600 kJ.

langley; L
Unit of solar irradiance.

One gram calorie per square centimeter. One L = 85.93 kwh/m2.

lattice
The regular periodic arrangement of atoms or molecules in a crystal of semiconductor material.
—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.