Savings calculator · Worked example

Solar and battery for a $900 quarterly power bill in Western Sydney

For a typical household paying $900 a quarter in Western Sydney (2150), the system that pays back best is 6.65 kW solar + 29 kWh battery: $9,741 after rebates, about $3,226 saved in the first year, paid for itself in 2.9 years and $28,960 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

6.65 kW solar + 29 kWh battery

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

Price after rebates
$9,741
Saving in year one
$3,226
Pays for itself in
2.9 years
Ahead after 10 years
$28,960

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

Solar only: the lowest outlay

5.7 kW solar

12 × JA Solar DeepBlue 4.0 Pro 475W N-Type Double Glass Monofacial (JAM54D40-475/LR) + SolaX 5kW SP Hybrid Inverter (2 MPPT)

Price after rebates
$3,782
Saving in year one
$1,788
Pays for itself in
2.1 years
Ahead after 10 years
$17,644

On Tango Energy · Everyday Easy, plan checked 26 October 2026

Another battery to compare

7.6 kW solar + 17 kWh battery

16 × JA Solar DeepBlue 4.0 Pro 475W N-Type Double Glass Monofacial (JAM54D40-475/LR) + GoodWe 18kWh 10kW 1-phase

Price after rebates
$10,952
Saving in year one
$3,243
Pays for itself in
3.2 years
Ahead after 10 years
$27,758

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

How this was worked out

  • A $900 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

$600 a quarter$700 a quarter$800 a quarter$1000 a quarter$1100 a quarter$1200 a quarter

$900 in Melbourne$900 in Brisbane