Battery Backup: Keeping the Lights On When the Grid Fails
“I have solar panels, so if the grid goes down in a storm, my house will keep running” is one of the most common misconceptions in renewable energy. Unfortunately, that's not how it works.
Why Solar Alone Won't Keep the Lights On
By law, standard solar inverters must shut down within milliseconds of a grid outage. This safety mechanism, called anti-islanding, stops your panels feeding live electricity back into street lines where technicians might be working to fix the fault. If you want your home to stay powered during an outage, you need a battery system with blackout protection, sometimes called EPS or backup functionality, as part of our Battery Storage: The Complete Guide. Not all backup is created equal, so here's what to consider if you're designing a system for the border region.
The Three Levels of Blackout Backup
Essential loads only (partial backup*): the most common, cost-effective approach. Your switchboard is re-wired to isolate a handful of critical circuits, such as the fridge, basic lighting, wifi router, phone chargers and a power point for a medical device, when the grid drops out.
Whole-home backup (full isolation): your entire switchboard is isolated from the street, so your whole house keeps running off stored battery power. The catch: a large ducted electric heating system running at full output through a winter blackout can draw more power than many standard batteries can sustain for long, potentially draining a 10 to 13kWh battery in under an hour, so this option needs careful energy management and often multiple battery units.
Black start capability: if an outage runs for multiple days and the battery drains to zero, black start lets the system restart the solar panels independently of the grid once the sun rises, recharging the battery and creating a self-sustaining loop during prolonged outages
*Partial Backup isn't included as standard on our default residential packages, it's quoted as an optional extra. Headline and entry-level system pricing is based on the system before backup is added, so if blackout protection matters to you, make sure it's specifically included in your quote.
Check the Changeover Speed
Before assuming your chosen battery will act like an uninterrupted power supply for sensitive equipment, it's worth checking the changeover switch speed for your specific system. Most modern battery backup systems switch over in well under a second, often within milliseconds, so you likely won't notice more than a flicker. That's a genuine advantage over older backup sources like standby generators, which typically take much longer to detect an outage and kick in. Ask CBR for the exact changeover spec of the system you're considering.
Where This Leaves You
Blackout backup isn't just for remote, off-grid properties anymore. If you're in an area prone to seasonal storms or grid instability, adding partial or full backup to your system offers real peace of mind. Talk to your CBR design specialist about which appliances are genuinely essential when the power goes out. See our complete range of battery storage options, check how location affects installation cost, or ask our team about blackout backup for your property, or drop us an email at info@cbrsolar.com.