Solar + Battery System Builder
Design an optimal system for your home in Queensland and compare solar-only vs solar + battery.
Your Home
$
Adds ~4kWh/day to your usage
Adds ~3kWh/day to your usage
$15,000
500025000
Recommended System
5kW Solar + 10kWh Battery
Net cost after rebates: $11,752
Solar Only Savings
$1,210/yr
Solar Only Payback
3.1 yrs
Solar+Battery Savings
$1,815/yr
Combined Payback
6.5 yrs
Comparison
- Annual Savings
- Net Cost
What this means
A 5kW solar system will save you about $1,210 per year with a 3.1-year payback. Adding a 10kWh battery increases savings to $1,815/year, but extends the combined payback to 6.5 years. Your estimated remaining quarterly bill drops to $0.
Next Step
Ready to make it happen?
Now that you know the numbers, we'll connect you with pre-vetted local installers — no spam, no pressure.
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Frequently Asked Questions
Do I need a battery with solar?
Not necessarily. Solar alone has a much faster payback. A battery makes more sense if you use most of your electricity in the evening, have low feed-in tariffs, or want backup power. Run the numbers with and without — this calculator does both.
What size system for a family of 4?
A typical family of 4 uses 20-25 kWh/day. A 6.6kW solar system covers this well. If you have an EV or heat pump, consider 8-10kW. For battery sizing, 10-13.5kWh covers a typical evening and overnight usage.
Can solar + battery power my whole house?
During most of the year, yes — with the right sizing. But in winter or during extended cloudy periods, you'll still draw some grid power. True off-grid requires oversized systems and significantly more battery capacity. Grid-connected with solar + battery is the sweet spot for most homes.