C
Cadmium Telluride (CdTe)
A polycrystalline thin-film photovoltaic material.
Cathode
The negative electrode in an electrochemical cell. Also, the negative terminal of a diode.
Cathodic protection
A method of preventing oxidation (rusting) of exposed metal structures, such as bridges and pipelines, by imposing between the structure and the ground a small electrical voltage that opposes the flow of electrons and that is greater than the voltage present during oxidation.
Cell
The basic unit of a photovoltaic panel or battery
Cell junction
The area of immediate contact between two layers (positive and negative) of a photovoltaic cell. The junction lies at the centre of the cell barrier or depletion zone.
Charge controller
The basic unit of a photovoltaic panel or battery
Charge controller
An electronic device which regulates the voltage applied to the battery system from the PV array. Essential for ensuring that batteries obtain maximum state of charge and longest life.
Cogeneration
The production of electricity and another form of useful energy (such as heat or steam) used for industrial, commercial, heating, or cooling purposes.
Concentrator
A PV module that uses optical elements to increase the amount of sunlight incident on a PV cell. Concentrating arrays must track the sun and use only the direct sunlight because the diffuse portion cannot be focused onto the PV cells. Efficiency is increased, but lifespan is usually decreased due to the high heat.
Concentrator (module, array, or collector)
An arrangement of photovoltaic cells that includes a lens to concentrate sunlight onto small-area cells. Concentrators can increase the power flux of sunlight hundreds of times.
Conversion efficiency (cell or module)
The ratio of the electric energy produced by a photovoltaic device (under one-sun conditions) to the energy from sunlight incident upon the cell.
Converter with Forced Commutation
Inverter whose output voltage form and frequency is produced by an oscillator electronic circuit, which allows the machine to work as a generator on an insulated grid.
Converter with Natural Commutation
Inverter whose output voltage frequency is set by the electric grid: it can function only if connected to electric grid.
Copper Indium Diselenide [CuInSe2]
Semiconductor polycrystalline compound used to produce PV cells.
It is usually indicated with the conventional acronym CIS.
Cosine
In a AC line, voltage and current are not always in phase; on the contrary, some phase displacement can occur, due to the inductive and capacitative effects of the loads. When the cosine of the phase angle between V and I (cos j) is equal to 1, there is no phase displacement; on the other side, when it is equal to 0, voltage and current are wattless (j = 90°), so that there is no transfer of power. Values between 0 and 1 indicate more or less marked displacements.
Crystalline silicon
Type of silicon having monocrystalline or polycrystalline structure.
Current, I [A]
The flow of electric charge in a conductor between two points with potential difference (voltage).
Current at maximum power (Imp)
The current at which maximum power is available from a module.
Cycle life
Number of discharge-charge cycles that a battery can tolerate under specified conditions before it fails to meet specified criteria as to performance (e.g., capacity decreases to 80-percent of the nominal capacity).
Czochralski (Process -)
A method of growing large size, high quality semiconductor crystal by slowly lifting a seed crystal from a molten bath of the material under careful cooling conditions.
