Savings calculator · Worked example

Solar and battery for a $400 quarterly power bill in Western Sydney

For a typical household paying $400 a quarter in Western Sydney (2150), the system that pays back best is 9.5 kW solar: $5,408 after rebates, about $1,240 saved in the first year, paid for itself in 4.2 years and $8,203 ahead after ten. Worked out 26 October 2026 on current prices, rebates and electricity plans.

Work it out for your own bill

The three worth comparing

Best over ten years

9.5 kW solar

20 × JA Solar DeepBlue 4.0 Pro 475W N-Type Double Glass Monofacial (JAM54D40-475/LR) + SolaX 7.5kW SP Hybrid Inverter (2 MPPT)

Price after rebates
$5,408
Saving in year one
$1,240
Pays for itself in
4.2 years
Ahead after 10 years
$8,203

On GloBird Energy · SOLARPLUS Residential (Flexible Rate)-Endeavour, plan checked 26 October 2026

Solar only: the lowest outlay

9.98 kW solar

21 × JA Solar DeepBlue 4.0 Pro 475W N-Type Double Glass Monofacial (JAM54D40-475/LR) + SolaX 7.5kW SP Hybrid Inverter (2 MPPT)

Price after rebates
$5,628
Saving in year one
$1,260
Pays for itself in
4.3 years
Ahead after 10 years
$8,202

On GloBird Energy · SOLARPLUS Residential (Flexible Rate)-Endeavour, plan checked 26 October 2026

Another battery to compare

2.85 kW solar + 29 kWh battery

6 × JA Solar DeepBlue 4.0 Pro 475W N-Type Double Glass Monofacial (JAM54D40-475/LR) + ESY 30.7kWh 6kW 1-phase

Price after rebates
$8,184
Saving in year one
$1,227
Pays for itself in
6 years
Ahead after 10 years
$6,513

On Kogan Energy · Kogan Energy with free FIRST, plan checked 26 October 2026

How this was worked out

  • A $400 quarterly bill, turned into daily use at typical NSW rates for postcode 2150.
  • A typical household's day: no answers about pools, air conditioning or an electric car. Yours can change the answer, so the calculator asks.
  • Every system size the roof and the grid connection allow, with and without each battery we install, priced after the federal battery rebate and solar STCs.
  • Each system on the retail plan that saves it the most, from every plan published for the postcode.
  • Installed by Sunbridge Energy NSW. An estimate, not a quote: a site inspection and your real bill give exact figures.

Other bills

$300 a quarter$500 a quarter$600 a quarter$700 a quarter

$400 in Melbourne$400 in Brisbane