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)

maintenance-free battery, maintenance free battery
A sealed battery to which water cannot be added to maintain electrolyte level.
majority carrier
Current carriers (either free electrons or holes) that are in excess in a specific layer of a semiconductor material (electrons in the n-layer, holes in the p-layer) of a cell.
maximum power point tracker; MPPT
Means of a power conditioning unit that automatically operates the photovoltaic generator at its maximum power point under all conditions.
maximum power point; MPP
The point on the current-voltage (I-V) curve of a module under illumination, where the product of current and voltage is maximum.

For a typical silicon cell, this is at about 0.45 volts.

maximum power tracking
Operating a photovoltaic array at the peak power point of the array's I-V curve where maximum power is obtained. Also called "peak power tracking".
megawatt; MW
A 1,000 kilowatts, or one million watts; standard measure of electric power plant generating capacity.
megawatt-hour, megawatt hour
One thousand kilowatt-hours or one million watt-hours.
microgroove
A small groove scribed into the surface of a solar cell, which is filled with metal for contacts.
minority carrier
A current carrier, either an electron or a hole, that is in the minority in a specific layer of a semiconductor material; the diffusion of minority carriers under the action of the cell junction voltage is the current in a photovoltaic device.
minority carrier lifetime
The average time a minority carrier exists before recombination.
modified sine wave
A waveform that has at least three states (for example, positive, off, and negative).

It has less harmonic content than a square wave.

modified sine wave
A waveform that has at least three states (such as, positive, off, and negative).

It has less harmonic content than a square wave.

modularity
The use of multiple inverters connected in parallel to service different loads.
module derate factor
A factor that lowers the photovoltaic module current to account for field operating conditions such as dirt accumulation on the module.
monolithic
Fabricated as a single structure.
—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.