Picture this: storm clouds roll in, the power goes out, but your neighbour's house stays lit up like Christmas morning while yours is plunged into darkness. They've got solar panels on their roof, just like you do. So what gives?
The reality might surprise you. Having solar panels doesn't automatically mean you'll have power during a blackout. In fact, most standard solar systems are designed to shut down the moment the grid goes off. And even if you've got a solar battery, that doesn't guarantee you'll have backup power when you need it most.
Let's sort out the confusion around solar battery backup, what actually works during a blackout, and how to make sure you're not left in the dark when the next storm hits.
Why standard solar systems don't work in blackouts
Here's something that catches a lot of people off guard: most solar panels are connected to what's called a grid-tied system. When the sun hits your panels, they generate power that either goes straight to your appliances or gets fed back into the electricity grid.
But here's the crucial bit - when the grid goes down, your solar system automatically shuts off too. This isn't a design flaw; it's actually a safety feature. Utility workers need to know that the lines they're fixing aren't carrying electricity from someone's rooftop solar setup. It keeps them safe while they get the power back on for everyone.
So even on the sunniest day, if there's a blackout, your standard solar panels won't help you brew that desperately needed cup of coffee.
Do solar panels work at night?
While we're busting myths, let's tackle this common question: do solar panels work at night? The short answer is no - solar panels need sunlight to generate electricity. When the sun goes down, your panels stop producing power.
This is where batteries come in. A solar battery stores excess energy your panels generate during the day, so you can use that stored power when the sun's not shining. But whether that battery actually works during a blackout depends entirely on how your system is set up.
Do solar batteries work during a blackout?
Not all solar batteries are created equal when it comes to backup power. Whether your solar battery works during a blackout depends on what type of system you have:
Standard battery systems store energy and help you use more of your own solar power, but they'll shut down along with your solar panels during an outage. These are great for reducing your electricity bills but won't help during a blackout.
Backup-ready battery systems can switch into what's called 'islanding' mode during an outage. When the grid goes down, these systems automatically disconnect from the network and use your stored battery power to keep essential appliances running.
The key difference is in the inverter and how the whole system is wired. A multimode or hybrid inverter can operate independently from the grid, creating your own little power island when the mains electricity is off.
What you need for backup power
If you want your solar and battery system to work during power outages, you'll need:
The right inverter: A hybrid or multimode inverter that can operate independently from the grid.
Backup-capable battery: Not all batteries can provide backup power. Make sure yours is specifically designed for it.
Proper installation: Your electrician needs to set up the system with backup circuits and ensure it can safely disconnect from the grid during outages.
Essential loads circuit: Most backup systems can't power your entire house during an outage. Instead, they're wired to a separate circuit that covers your essentials - things like lights, fridge, modem, and maybe a few power points.
How long does backup power last?
The million-dollar question: how long will your solar battery backup actually last during a blackout?
It depends on several factors:
Your battery size matters, obviously. A larger battery stores more energy and lasts longer. But what you're powering makes an even bigger difference.
Running just your fridge, lights, and modem? A decent-sized battery could keep those going for days. Try to run your air conditioning, pool pump, and electric hot water system? You might be back in the dark within hours.
During daylight hours, if your solar panels are still producing power (and your backup system allows it), you can actually recharge your battery while using it. This extends your backup time significantly, especially on sunny days.
Planning for extended outages
If you live in an area prone to storms or bushfires, thinking about extended power outages makes sense. Here's how to make your backup power last:
Prioritise your loads: Work out what's actually essential. Your coffee machine might feel important, but your fridge and medical equipment come first.
Install a changeover switch: This lets you manually switch non-essential appliances off during an outage, preserving battery power for what matters most.
Consider a larger battery: If extended outages are common in your area, investing in more storage capacity could be worthwhile.
Have a backup plan: Even the best battery system has limits. Know where your torches are and have alternative cooking methods ready.
Does solar work in a blackout with the right setup?
Absolutely. With a properly configured backup system, your solar panels can continue charging your battery during the day while you're running on stored power. This creates a sustainable cycle where sunny days top up your battery for the next night.
The key is having a system that's designed for backup power from the start, not trying to retrofit standard equipment to work during outages.
What about costs?
Adding backup capability to your solar battery system does increase the upfront cost. You're looking at additional equipment (like a hybrid inverter if you don't already have one) and more complex installation work.
But if you regularly experience power outages, the peace of mind and avoided inconvenience can make it worthwhile. Plus, you're still getting all the regular benefits of solar and battery - reduced electricity bills and more energy independence.
Getting backup power right
If backup power is important to you, discuss it with your installer from the beginning. Trying to add backup capability to an existing standard system often costs more than doing it right the first time.
Be realistic about what you need to power during an outage. A system that can run your entire house will cost significantly more than one that covers essentials only.
And remember, even backup systems have limits. They're designed for temporary power during outages, not for going completely off-grid permanently.
Here's the thing
Most people assume that having a solar battery means they're sorted for blackouts. They're not. Unless you've specifically paid for backup capability, your battery will be about as useful as a brick when you need it most.
If you're in a storm-prone area or just hate the idea of losing power, talk to your installer about backup systems before you buy anything. It costs more upfront, but at least you'll know what you're actually getting.
Don't be the person who finds out their expensive battery system doesn't work during the one time they actually need it to.
Thinking about getting a battery? Use our Battery Compatibility Checker to find systems that work with Amber before you buy. With the federal rebate making batteries more affordable, now's the perfect time to invest in a system that does both - backup power during outages and wholesale earnings the rest of the time.
