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)

annual solar savings
The annual solar savings of a solar building is the energy savings attributable to a solar feature relative to the energy requirements of a non-solar building.
The positive electrode in an electrochemical cell (battery).

Also, the earth or ground in a cathodic protection system or the positive terminal of a diode.

antireflection coating
A thin coating of a material applied to a solar cell surface that reduces the light reflection and increases light transmission.
array current
The electrical current produced by a photovoltaic array when it is exposed to sunlight.
array operating voltage
The voltage produced by a photovoltaic array when exposed to sunlight and connected to a load.
autonomous system
A hybrid photovoltaic system not connected to a grid.
The quality or condition of a photovoltaic system being available to provide power to a load.

Usually measured in hours per year. One minus availability equals downtime.

azimuth angle
The angle between true south and the point on the horizon directly below the sun.
balance of system
Represents all components and costs other than the photovoltaic modules/array.

It includes design costs, land, site preparation, system installation, support structures, power conditioning, operation and maintenance costs, indirect storage, and related costs.

band gap
In a semiconductor, the energy difference between the highest valence band and the lowest conduction band.
band gap energy; Eg
The amount of energy (in electron volts) required to free an outer shell electron from its orbit about the nucleus to a free state, and thus promote it from the valence to the conduction level.
barrier energy
1. The energy given up by an electron in penetrating the cell barrier.
2. A measure of the electrostatic potential of the barrier.
base load
The average amount of electric power that a utility must supply in any period.
Two or more electrochemical cells enclosed in a container and electrically interconnected in an appropriate series/parallel arrangement to provide the required operating voltage and current levels.

Under common usage, the term "battery" also applies to a single cell if it constitutes the entire electrochemical storage system.

battery available capacity
The total maximum charge, expressed in ampere-hours, that can be withdrawn from a cell or battery under a specific set of operating conditions including discharge rate, temperature, initial state of charge, age, and cut-off voltage.
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.