SMA S Technical Description page 177

SMA Solar Technology AG Glossary
Slave
A configuration setting which assigns a subordinate role in a cluster to a Sunny Island or Sunny
Backup inverter. Thus, this device is relieved of control tasks and monitoring tasks, which must (or may)
only be performed by one device in a cluster (-> master). Slave devices accept the configuration
settings, present firmware, and start/stop commands from the master, and report these events, as well
as warnings and error messages.
SOC
State of Charge: the charge level of the batteries, see Charge level. If, for example, 25 Ah are taken
from a 100-Ah battery, the charge level (SOC) is then 75 %.
SOH
State of Health: describes the relationship between the present capacity and the battery's nominal
value, given as a percentage.
Solar Cell
An electronic component which generates electrical energy when irradiated with sunlight. Since the
voltage produced by a single solar cell is very small (approx. 0.5 V), several solar cells are combined
to form a solar module. The most common semiconductor material presently used for solar cells is
silicon, which is manufactured in different forms (monocrystalline, polycrystalline, amorphous). In
addition to vastly different mechanical variations, which are usually designed to increase the level of
efficiency, completely new materials are currently being tested (cadmium telluride, cadmium indium
sulphide, titanium dioxide and many others).
Solar Energy
"Sun energy", this means energy from sunlight or other solar irradiation (heat and/or UV radiation).
Solar Module
Electrical connection of several solar cells encapsulated in a housing to protect the sensitive cells from
mechanical stress and environmental influences.
Stand-Alone Grid System
An energy generation system which is completely independent of any external power sources.
String
Describes a group of solar modules connected in series. A PV system usually consists of a number of
strings, which avoids excessive yield losses caused by variations in shadowing on different modules.
String Inverter
An inverter concept which avoids the disadvantages of the central inverter concept. The PV generator
is split into individual strings, each of which is connected to the external grid by means of its own string
inverter. This greatly simplifies installation and reduces the yield losses which can be caused by
manufacturing deviations or variations in shadowing on the solar modules.
Sub Cluster (Extension Cluster)
Cluster in a multicluster system which is subordinate to a main cluster, and thus does not lead the entire
system.
Technical Description SBU2200-TEN083320 177