Off-grid solar powers a property without any grid connection — no poles, no lines, no electricity bills. For most rural and remote properties in Australia, the upfront cost ($18,000–$50,000 depending on system size) compares favourably to grid connection quotes that routinely reach $60,000–$100,000. 100UP sizes every system against worst-case winter production, not summer averages — because that's the difference between a system that works in July and one that doesn't.
Off-grid solar supplies your home with electricity without a connection to the main power grid. No poles. No lines. No electricity bills.
It’s not a new idea . Though recently the systems have changed a lot. Older setups needed separate battery chargers, regulators, and a tangle of components to make it work. Modern systems are much simpler. Most run on three or four core components, and they’re more reliable than anything available a decade ago.
Four main components do the work:
The complexity isn’t in the component count. It’s in getting the sizing right for your property and your location.
More than grid-tied solar. That’s the honest answer.
You’re not just buying panels. You’re buying energy independence. Batteries, inverters, and installation all add to the cost. And the system needs to be sized properly, or it won’t perform when you need it most.
Here’s a rough guide to installed system costs in Australia:
| Household Size | Typical System | Installed Cost (approx.) |
|---|---|---|
| 1–2 people | 5–8 kW | $18,000 – $22,000 |
| 3 people | 10 kW | $28,000 – $30,000 |
| 4 people | 15 kW | $34,000 – $38,000 |
| 5+ people | 20 kW | $46,000 – $50,000 |
Prices are approximate and after rebates. System cost varies by location, equipment quality, and battery storage required.
Worth keeping in mind: connecting a rural property to the grid typically starts at $25,000. Figures of $60,000 to $100,000 are common. Against that, an off-grid system starts to look like the rational choice.
A general guideline: start with 10 kWh per day for one person, then add 5 kWh per day for each additional person. A household of three typically needs around 20 kWh per day, which points to a 10 kW system.
That gives you a starting point. But a starting point isn’t a design.
Where the general guide falls short: it’s based on average consumption and average solar production. Most off-grid systems that fail or end up generator-dependent, were sized against averages. They work great in summer. Then July arrives.
The 100UP approach to designing Off Grid solar adds one more layer. We use a baseline of 5 kWh for the property itself, plus 5 kWh per occupant. We size that against worst-case winter production. In Ballarat, a clear June day gives you around 2.5 to 3 peak solar hours. Overcast stretches can cut that further. A system sized for that is one that runs without generator dependency when it matters most.
→ Use the off-grid sizing calculator to model your property
For larger properties, higher occupancy, or agricultural use, 20 kW systems are common. They handle more load, more battery storage, and more complex energy needs , but the sizing and design principles are the same.
→ See the 20 kW system guide or keep reading for to learn about our recent projects specs, installs and pricing
This is a 50kW off-grid solar system going in, one of the larger residential installs we’ve done.Three ground-mounted Jinko 470W panel arrays feed into three MPPT charge controllers. Power runs underground through steel conduit to the shed, where two Victron inverters and a Pylontech battery system take over from there.No grid connection. No power bills.…
12kW of Off-Grid Power Installed near Ballarat – Reliable Energy Every Winter Dereel sits just outside Ballarat. In winter, that means shorter days and consistent cloud cover to consider. Stretches of grey weather expose every weakness in an undersized system. When this property owner came to us they need to run through a real Dereel…
Off-grid makes sense when grid connection is expensive, unavailable, or simply not worth it. The numbers usually favour off-grid:
The upfront cost is real, but so is the alternative. It’s not right for everyone. If grid power is available and affordable, a hybrid solar-plus-battery system is often the better fit. We’ll tell you that upfront.
If you’re not sure, the off-grid system sizing pricing guide covers the full cost picture, what’s included, what varies, and how to compare quotes properly. Or get in touch a quick conversation usually makes it clear.
Larger properties tend to experience greater variation in power use. Family gatherings, guests, holiday periods and short-stay accommodation can all create sharp increases in demand that smaller systems struggle to handle.
A two-bedroom off-grid home can serve many roles. It might be a permanent residence, a holiday property, or somewhere that regularly hosts family and visitors. The design needs to account for how people actually live.
