Battery backup power for Sale homes
How a solar battery in Sale can keep lights, the fridge and the modem running in a blackout, and why most grid-connected systems switch off instead.
A solar battery only keeps your Sale home running in a blackout if the inverter and wiring were set up for backup. Standard grid-connected systems, with or without a battery, shut down when the grid fails. A multimode or hybrid system can separate the house from the grid and run a chosen set of circuits, usually lights, the fridge and the internet modem, from stored energy and whatever the panels are making.
This page is about outage design. Choosing a battery size and the federal discount are covered on the home battery installation page. Sale Solar does not install anything itself: the independent electricians who receive enquiries through this site design and quote each backup job.
Why does my solar switch off when the power goes out?
Solar Victoria explains that standard solar systems are designed to stop during an outage. That protects the home from surges and protects people who may be working on nearby wires. An inverter still feeding power into a line that workers believe is dead would put them at serious risk.
So a household with panels on the roof can still sit in the dark during a storm. Owning a battery does not change that by itself. Many batteries sold for bill savings or for virtual power plant programs are set up to trade energy with the grid, and Solar Victoria notes that these are not customised for outage use even when the hardware has the ability.
How does islanding work?
A backup-capable system has a transfer device that disconnects the home from the grid as soon as supply drops. The battery and inverter then form a small private network inside the house. Solar Victoria calls this islanding, because the home becomes an island cut off from the grid. Power flows to your backed-up circuits but never back out to the street.
When AusNet restores supply, the system reconnects and goes back to normal operation. Switchover times differ between products, which matters if you run a computer or anything that dislikes a brief flicker, so ask the provider what transfer time the proposed equipment has.
Backup options compared
| Setup | What happens in an outage | Suits |
|---|---|---|
| Standard grid solar, no battery | Everything stops until the grid returns | Homes that rarely lose power or have a generator |
| Battery set up for savings only | Battery and solar shut down with the grid | Households chasing lower bills, not resilience |
| Hybrid or multimode inverter, essential circuits | Chosen circuits keep running from battery and solar | Most homes wanting the fridge, lights and modem kept on |
| Hybrid or multimode, whole-home backup | Most of the house runs, within the battery and inverter limits | Larger batteries and households willing to manage their use during an outage |
| Battery plus generator inlet | Battery first, then a generator for long outages | Rural properties that want cover for longer outages |
Each step down the table needs more design work and usually more switchboard changes. Solar Victoria notes that backup configuration is done by the installer and may add to the cost.
Which circuits should be backed up?
Start with a short list. Solar Victoria’s planning questions suggest thinking about lights, the internet modem and the fridge first. Most providers wire those to a separate essential-loads board so the battery is not drained by an oven, a heat pump or an electric car charger in the first hour.
Questions to work through before you ask for quotes:
- Which rooms do you need lit at night during a blackout?
- Does anyone work from home and need the modem and a laptop running?
- Do you have a well pump, sump pump or septic system that needs power?
- Is your hot water, heating or cooking electric, and do you want any of it backed up?
- How long have past outages at your address lasted?
Solar Victoria points out that all-electric homes are hit harder by outages than homes that still use gas, because electric cooktops, heating and hot water all stop at once. As more Sale households replace gas appliances, the case for a backed-up circuit for at least one heater or a cooktop gets stronger. Whether the battery can carry those loads is a design question for the provider.
What about medical equipment?
If anyone in the house relies on powered medical equipment, get specialist advice before relying on a battery. Solar Victoria’s backup power guidance says home battery systems are typically not appropriate as the primary source for that kind of load.
Outages in Gippsland: how often does it happen?
Outages in Victoria are uncommon, but eastern Victoria is a long, mostly rural network and storms can take down lines across a wide area. During the February 2024 storms, AusNet reported about 226,000 of its customers without power across its network, about 30,000 of them in Gippsland, according to a local newspaper report quoting AusNet. If your place is on a farm out past Longford or in the hardwood timber country around Heyfield, keep your own record of past outages, because it is the best guide a provider has.
Tell the provider how often you lose supply and for how long. A house that loses power twice a year for an hour needs a different system from one that has spent two days without supply.
What does a careful provider check before quoting backup?
A provider who takes backup seriously will:
- inspect the switchboard and say whether it can take an essential-loads board or needs replacing
- confirm the existing inverter can island, or quote a hybrid replacement
- check the battery’s continuous output, not only its storage, against the loads you want running
- explain the transfer time and which appliances may restart
- install and test the system to AS/NZS 5139 for the battery and AS/NZS 4777.2 for the inverter, and organise the independent inspection and Certificate of Electrical Safety
- show you how to tell when the house is running on backup and how to shut the system down
Be wary of anyone who promises the whole home will run for days without asking about your loads.
What does battery backup cost in Sale?
A 10 kWh usable battery installed averages $7,784 to $8,284 per system nationally in a recent battery price index, after the federal discount. If your current inverter cannot island, a hybrid inverter upgrade is around $2,500 to $4,500 on a typical home system. Backup wiring and an essential-loads board are extra and depend on your switchboard. The solar only versus solar and battery guide helps if you are still deciding whether a battery is worth it at all. When you are ready, you can send a battery backup enquiry and ask for the backup work to be priced as its own line.
Next step: describe what you want kept running
When you ask for a backup power quote, list the appliances you want running during an outage and roughly how long you want them to last. Add a photo of your switchboard with the cover open, a photo of the inverter label showing the brand and model, and your battery details if you already have one. Mention your suburb, whether the house is all-electric, and how often and for how long you have lost power at this address.
Frequently asked questions
- Can I add backup to the battery I already have?
Sometimes. It depends on whether the battery and inverter support off-grid operation and whether the switchboard can be rewired for an essential-loads circuit. An electrician needs the model numbers and a look at the board to say.
- Will my solar panels keep charging the battery during a blackout?
On a system designed for backup, usually yes, so a sunny outage can last much longer than a battery alone would allow. On a standard system the panels stop along with everything else.
- How long will a battery run my fridge and lights?
That depends on the battery's usable storage, how much the backed-up appliances draw and how much sun there is. The provider should work it out from your actual loads rather than give a single figure.
- Is a generator a better choice for long outages?
A generator can run for as long as you have fuel, but it has fuel costs, noise and emissions. Some rural homes pair a battery for short outages with a generator inlet for long ones. Ask the provider whether a safe changeover can be wired in.
- Does backup stop me joining a virtual power plant?
Not always, but VPP setups are built for trading with the grid. If you want both, ask how much stored energy the system keeps in reserve for outages and whether you can change that setting.