Island mode
Island mode in the SpeicherCampus context: a local grid made of storage, PV and loads. Technically, the term is usually described as operation without the public grid.
What does island mode mean?
In island mode, the storage system forms its own local grid — disconnected from the public grid. The PCS then sets voltage and frequency (grid-forming), and PV systems, generators and loads work together inside this “island”.
This is more demanding than normal grid-parallel operation: the storage system must handle inrush currents on its own, keep the frequency stable, curtail PV generation inside the island and resynchronize cleanly when the grid returns.
What matters in practice
- verify the PCS’s grid-forming capability — not every system can island
- inrush currents of large motors size the island power
- PV inside the island needs curtailment logic (otherwise over-frequency)
- distinguish permanent off-grid operation from a backup-power island
Practical example
A mountain farm without a grid connection runs PV, storage and diesel as a permanent island: PV by day, battery by night, the generator only as a winter reserve. The PotisCabinet D9 coordinates the sources — the generator runs 80 % less than before.
The SpeicherCampus perspective
SpeicherCampus reviews island projects separately from standard commercial projects: load structure, inrush currents and source coordination decide the system choice here.