Island mode & black start
Grid down. Power on.
When the grid fails, COR.stor switches to its own supply automatically. Lighting, refrigeration, heating pumps and internet keep running.
- typically 20 ms switchover
- 70 kWh usable
- island- and black-start capable
02 Island mode
The building stays supplied.
In island mode the system keeps supplying the building for as long as the public grid is down — from the storage unit and, in COR.set, from the heat and power plant.
The switchover happens automatically, without you lifting a finger. The whole building is supplied within 15 or 30 kVA, not a single backup socket.
COR does not replace the grid. COR makes you less dependent on it.
Grid failure
The grid goes down.
COR.stor switches to island mode — typically within 20 ms.
Island mode
The storage unit takes over.
The building keeps running from the storage unit. Most devices carry on without a noticeable dropout.
In COR.set · heating season
The heat and power plant recharges.
When the charge level drops, the storage unit calls for the COR.gen heat and power plant by itself.
03 Black start
Restart even without the grid.
Black-start capable means the system can re-establish its own supply even when the public grid is not available.
In COR.set this also applies to the heat and power plant: COR.gen starts without the grid, and the storage unit gives the signal. During the heating season it keeps heating and recharges the storage unit as it runs. The limit is then not the battery but the pellet supply.
04 The proof
Typically 20 milliseconds switchover time.
That is how quickly COR.stor takes over when the grid fails. Most devices keep running without a noticeable dropout.
Data sheet value: typically 20 ms, maximum 80 ms, depending on the type of fault.
05 Blackout preparedness
87% expect one day. The Civil Protection Association advises ten to fourteen.
In EY’s Blackout Readiness Check (January 2026, 1,000 respondents), 87 per cent of Austrians assume the power will be back within 24 hours; more than half expect no more than five hours. The Austrian Civil Protection Association recommends stocking up for ten to fourteen days. One household in five has made no preparations at all.
On 28 April 2025, 55 million people on the Iberian Peninsula lost power. It took more than twelve hours to bring the grid back — triggered by a local fault that cascaded.
COR.stor bridges the gap — switchover typically in 20 milliseconds — and keeps the whole property running within 15 or 30 kVA: light, refrigeration, heating pumps, internet. No generator set, no diesel, no noise.
Sources: EY Blackout Readiness Check, 13 Jan 2026 · ENTSO-E final report on the Iberian Peninsula outage of 28 Apr 2025 · Austrian Civil Protection Association, Blackout guide
06 Self-test
How long does your storage unit last?
Choose what should keep running during an outage. The calculation runs against 70 kWh of usable capacity, less conversion losses.
Your home runs for
12.9 dayswith a fully charged battery
4.9 kWh/day
Civil Protection Association recommends: 10–14 days
Recommendation met.
Guide values for an average household, not a guarantee. Conversion losses of 10% and a system base load of 0.5 kWh per day are included. Yield from a PV system is not counted — with sunshine the storage unit lasts longer. Actual consumption depends on appliances, building and use.