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Solar-only systems shut down during a blackout due to anti-islanding safety rules. With a battery and backup enabled, your home can operate in island mode, powering essential circuits. Most systems do not support full-house backup. Runtime depends on battery size, usage and sunlight, with solar able to recharge the battery during extended outages.
What Happens If You Only Have Solar Panels?
If you have a solar-only system with no battery, your system will shut down completely during a blackout. Even on a bright sunny day, your panels will not power your home.
This is due to a mandatory safety feature known as anti-islanding. It prevents your inverter from sending electricity back into the grid, which could endanger line workers repairing the fault. The shutdown is automatic and required under Australian standards. It is not a fault with your system.
What Changes If You Have a Battery Installed?
If your solar system includes a compatible battery and hybrid inverter, your home can continue operating during a blackout, provided backup functionality has been installed and enabled.
When the grid fails, the system detects the outage and automatically disconnects your home from the network. This process, often called island mode, creates a safe, independent power supply for your house. The battery begins supplying electricity, and if it is sunny, your solar panels can continue generating energy and recharge the battery during the outage.
Will Your Whole House Stay On?
In most Australian homes, the answer is no. The majority of systems are configured to power essential circuits only.
These commonly include:
• Refrigerator and freezer
• Selected lighting circuits
• Internet modem
• A few designated power outlets
High-demand appliances such as air conditioners, electric hot water systems and ovens are typically excluded from backup circuits. Whole-home backup is possible but requires a significantly larger and more expensive battery system.
How Long Will Backup Power Last?
Backup duration depends on three key factors: battery size, household usage and weather conditions. A typical 10 kWh battery can often run essential loads for a full day or longer if usage is managed carefully.
If the outage continues and there is sufficient sunlight, solar panels can recharge the battery during the day, extending operation for multiple days. However, during prolonged cloudy weather, stored energy will eventually deplete. The switchover to backup mode is usually fast, though you may notice a brief flicker as the system transitions from grid power to battery supply.
