SMA Solar Technology AG
Symbol
Explanation
Battery
Lead-acid battery
Lithium-ion battery
Utility grid
SMA Energy Meter
Off-grid system
Battery-backup system
Grid disconnection
Grounding device
1.5
Explanation of Used Terms
Term
Explanation
Off-grid system
Off-grid systems are self-sufficient utility grids. The Sunny Island forms the stand-alone grid
and regulates the balance between the energy that is fed in and the energy that is used.
Battery-backup sys-
In the event of grid failure, a battery-backup system supplies loads with energy and a PV sys-
tem
tem disconnected from the utility grid with voltage.
SMA Flexible Stor-
The Sunny Island uses the connected battery for the intermediate storage of excess PV en-
age System
ergy in the SMA Flexible Storage System.
Grid disconnection
The functional group grid disconnection is part of the automatic transfer switch of the battery-
backup system and disconnects the battery-backup grid from the utility grid in the event of
grid failure.
Grounding device
In the case of all-pole disconnection, the functional group grounding device is part of the au-
tomatic transfer switch of the battery-backup system and enables protection against indirect
contact with live components.
Quick Reference Guide
1 Information on this Document
Symbol
Explanation
PV array
Existing protective devices (e.g. in the
SMA Flexible Storage System)
AC loads
Generator
Existing house distribution board with
protective devices (e.g. in the battery-
backup system)
Grid-connection point with energy me-
ter of electric utility company
SMA Flexible Storage System
Grid disconnection with all-pole discon-
nection
Grid disconnection without all-pole dis-
connection
SI44M-60H-80H-12-IS-xx-12
5