11 GLOSSARY
A
Accumulator:
An installation component capable
of storing electrical energy by converting it into
chemical energy. It is made up of several batteries
connected in series or parallel.
Air mass:
Measurement of the distance light
travels through the atmosphere in its path to
the surface of the Earth.
Alternating current:
In an alternating current
(AC) the electrons, from their fixed position in
the cable (mean), oscillate from one side of
the mean to the other within the same space
or amplitude and at a determined frequency
(number of oscillations per second)
B
Battery:
Batteries or accumulators store excess
energy generated by the photovoltaic system so
it can be supplied at times when the system is
not generating power (for example at night or on
cloudy days).
Bypass diode:
A device connected in parallel to
the modules to divert the flow of current when
solar cells are shaded or a cell fails.
C
Cell efficiency:
The percentage of solar energy
(captured by a solar cell exposed to full sunlight)
which is transformed into electrical energy.
Charge regulator:
Also called the control unit or
charge controller. A component which controls
the flow of current towards the battery and from
the battery to devices in order to protect the battery
from electrical surges and discharges.
Connection to the public power grid:
A system
generating electricity may be connected to the public
power grid.
D
Direct current:
Direct current (DC) is generated
from a continuous stream of electrons (negatively
charged) always travelling in the same direction,
from the negative terminal to the positive terminal.
As the electrons set off in this direction, the gaps
or absence of electrons (positive charged particles)
move in the opposite direction, from the positive to
the negative terminal.
E
Electric intensity (Current):
Electrical magnitude
defined as the amount of electricity that passes
through a section of conductor cable in one
second. It is measured in amperes (A).
Electric tension (Voltage):
Difference in electric
potential which must exist between connection
terminals or between two live points in a system
for current to flow through said system. The unit
of measurement is the volt (V).
Electrical conductor:
Any material capable of
conducting an electric current.
Electrical installation:
Group of devices and
associated circuits for a specific purpose:
the production, conversion, transformation,
transmission, distribution or use of electrical energy.
Electrical power:
The capacity of electrical
devices to produce work (the amount of energy
consumed per unit time). The unit of measurement
is the watt (W) or kilowatt (kW).
Electricity consumption:
Number of watt hours
(Wh) or kilowatt hours (kWh) used to make an
electrical device function for a given time. Depends
on the power of the device and the amount of time
it is using electricity.
Electricity meter:
An instrument which measures
the electrical energy consumed. It may be the property
of the client or the electricity company. It measures
consumption in kWh.
G
Grounding (Earthing):
Connection to the ground
to use as a backup pathway, providing an
alternative route for the current to flow back to
the ground in an electrical circuit and arbitrarily as
a zero potential point.
I
I-V curve:
Current (I) and voltage (V) curves
show the I and V characteristics of a particular
photovoltaic module, measured under specific
radiation conditions. Essential information to
characterize photovoltaic modules.
J
Junction box:
A box integrated into the solar tile which
houses the cables used for electrical connections.
K
Kilowatt (kW):
A thousand watts (1 kW = 1.000 W)
33
