On this page, I have done some calculations using the SolarQuotes Solar and Battery Payback Calculator. System sizes calculated both with and without a battery (Tesla Powerwall 2) are 3kW, 6.6kW, 10kW, 15kW and 20kW.
These calculations can help you estimate possible yearly electricity bills with solar power and battery storage. See how solar could affect your electricity usage during different times of the year, find solar system payback times and see if installing batteries is the right option for you.
To complete these calculations, I have entered the postcode for Paramatta 2150 as its reasonably central to Sydney. It's safe to say that the results would be almost identical for most Sydney suburbs.
All the calculations listed below have the same default input values. For a more precise result based on your own location and needs, please click on the button below and input your own values.
Default values:- North facing solar panels.
- Solar panels mounted at 22°.
- Grid supplied electricity cost per kWh inc GST: 29c.
- Annual electricity bill: $1420.00.
- Daily electricity supply charge: 0.81c.
- Solar feed-in tariff rate per kWh: 0.16c.
- Battery type: Tesla Powerwall 2, 13.5 kWh.
3kW Solar Power Systems in Sydney
3kW Solar with 3kW String Inverter
- System installation cost: $3,000 fully installed after solar rebate.
- Your first year's savings: $957.
- 10-year savings: $10,385.
- 20-year savings: $22,114.
- IRR:33.91%.
- Payback time: 3 years and 1 month.
- Yearly self-consumption: 44% of solar used, 56% exported to the grid.
- Seasonal self consumption: Summer 50%, Autumn 41%, Winter 45%, Spring 38%.
Includes an inverter replacement at the 12-year mark. The replacement cost is $855 ($600 for the unit and $255 for 3% inflation).
3kW Solar with 3kW String Inverter and 13.5kWh Tesla Powerwall 2
- System installation cost: $19,000 fully installed after solar rebate.
- Your first year's savings: $1,171.
- 10-year savings: $13,225.
- 20-year savings: $29,677.
- IRR: 8.02%.
- Payback time: 14 years and 2 months.
- Yearly self-consumption: 81% of solar used, 19% exported to the grid.
- Seasonal self consumption without batteries: Summer 47%, Autumn 38%, Winter 42%, Spring 35%.
Includes an inverter replacement at the 12-year mark. The replacement cost is $855 ($600 for the unit and $255 for 3% inflation).
Seasonal Electricity Bills for 3kW Solar in Sydney
Summer 3kW Solar in Sydney
- Solar with batteries: $21 DEBIT.
- With solar: $63 DEBIT.
- Without solar: $358 DEBIT.
Autumn 3kW Solar in Sydney
- Solar with batteries: $64 DEBIT.
- With solar: $128 DEBIT.
- Without solar: $328 DEBIT.
Winter 3kW Solar in Sydney
- Solar with batteries: $163 DEBIT.
- With solar: $226 DEBIT.
- Without solar: $416 DEBIT.
Spring 3kW Solar in Sydney
- Solar with batteries: $1 DEBIT.
- With solar: $47 DEBIT.
- Without solar: $318 DEBIT.
| Month | kWh Produced |
|---|---|
| January | 453 kWh |
| February | 395 kWh |
| March | 357 kWh |
| April | 327 kWh |
| May | 254 kWh |
| June | 260 kWh |
| July | 278 kWh |
| August | 334 kWh |
| September | 403 kWh |
| October | 455 kWh |
| November | 440 kWh |
| December | 462 kWh |
6.6kW Solar Power Systems in Sydney
6.6kW Solar with 5kW String Inverter
- System installation cost: $6,600 fully installed after solar rebate.
- Your first year's savings: $1,782.
- 10-year savings: $18,630.
- 20-year savings: $38,005.
- IRR: 27.86%%.
- Payback time: 3 years and 8 months.
- Yearly self-consumption: 20% of solar used, 80% exported to the grid.
- Seasonal self cunsumption: Summer 25%, Autumn 20%, Winter 23%, Spring 19%.
Includes an inverter replacement at the 12-year mark. Replacement cost is $1,426 ($1,000 for the unit and $426 accounting for 3% inflation).
6.6kW Solar with 6kW String Inverter and 13.5kWh Tesla Powerwall 2
- System installation cost: $22,600 fully installed after solar rebate.
- Your first year's savings: $2,040.
- 10-year savings: $22,043.
- 20-year savings: $47,092.
- IRR: 10.33%.
- Payback time: 10 years and 3 months.
- Yearly self-consumption: 40% of solar used, 60% exported to the grid.
- Seasonal self consumption without batteries: Summer 25%, Autumn 20%, Winter 23%, Spring 19%.
Includes an inverter replacement at the 12-year mark. Replacement cost is $1,426 ($1,000 for the unit and $426 accounting for 3% inflation).
Seasonal Electricity Bills for 6.6kW Solar in Sydney
Summer 6.6kW Solar in Sydney
- Solar with batteries: $220 CREDIT.
- With solar: $180 CREDIT.
- Without solar: $358 DEBIT.
Autumn 6.6kW Solar in Sydney
- Solar with batteries: $115 CREDIT.
- With solar: $53 CREDIT.
- Without solar: $328 DEBIT.
Winter 6.6kW Solar in Sydney
- Solar with batteries: $44 CREDIT.
- With solar: $56 DEBIT.
- Without solar: $416 DEBIT.
Spring 6.6kW Solar in Sydney
- Solar with batteries: $241 CREDIT.
- With solar: $197 CREDIT.
- Without solar: $318 DEBIT.
| Month | kWh Produced |
|---|---|
| January | 974 kWh |
| February | 847 kWh |
| March | 779 kWh |
| April | 718 kWh |
| May | 560 kWh |
| June | 572 kWh |
| July | 611 kWh |
| August | 735 kWh |
| September | 875 kWh |
| October | 984 kWh |
| November | 949 kWh |
| December | 992 kWh |
10kW Solar Power Systems in Sydney
10kW Solar with 9kW String Inverter
- System installation cost: $10,000 fully installed after solar rebate.
- Your first year's savings: $2,602.
- 10-year savings: $26,822.
- 20-year savings: $53,245.
- IRR: 26.35%.
- Payback time: 3 years and 10 months.
- Yearly self-consumption: 13% of solar used, 87% exported to the grid.
- Seasonal self consumption: Summer 15%, Autumn 12%, Winter 13%, Spring 11%.
Includes an inverter replacement at the 12-year mark. Replacement cost is $2,566 ($1,800 for the unit and $766 accounting for 3% inflation).
10kW Solar with 9kW String Inverter and 13.5kWh Tesla Powerwall 2
- System installation cost: $26,000 fully installed after solar rebate.
- Your first year's savings: $2,860.
- 10-year savings: $30,243.
- 20-year savings: $62,351.
- IRR: 11.91%.
- Payback time: 8 years and 9 months.
- Yearly self-consumption: 26% of solar used, 74% exported to the grid.
- Seasonal self consumption without batteries: Summer 16%, Autumn 13%, Winter 14%, Spring 12%.
Includes an inverter replacement at the 12-year mark. Replacement cost is $2,566 ($1,800 for the unit and $766 accounting for 3% inflation).
Seasonal Electricity Bills for 10kW Solar in Sydney
Summer 10kW Solar in Sydney
- Solar with batteries: $468 CREDIT.
- With solar: $431 CREDIT.
- Without solar: $358 DEBIT.
Autumn 10kW Solar in Sydney
- Solar with batteries: $286 CREDIT.
- With solar: $225 CREDIT.
- Without solar: $328 DEBIT.
Winter 10kW Solar in Sydney
- Solar with batteries: $202 CREDIT.
- With solar: $103 CREDIT.
- Without solar: $416 DEBIT.
Spring 10kW Solar in Sydney
- Solar with batteries: $484 CREDIT.
- With solar: $442 CREDIT.
- Without solar: $318 DEBIT.
| Month | kWh Produced |
|---|---|
| January | 1,509 kWh |
| February | 1,316 kWh |
| March | 1,191 kWh |
| April | 1,089 kWh |
| May | 847 kWh |
| June | 866 kWh |
| July | 925 kWh |
| August | 1,115 kWh |
| September | 1,344 kWh |
| October | 1,516 kWh |
| November | 1,467 kWh |
| December | 1,539 kWh |
15kW Solar Power Systems in Sydney
15kW Solar with 13kW String Inverter
- System installation cost: $15,000 fully installed after solar rebate.
- Your first year's savings: $3,789.
- 10-year savings: $38,726.
- 20-year savings: $75,996.
- IRR: 25.33%.
- Payback time: 4 years and 0 months.
- Yearly self-consumption: 9% of solar used, 91% exported to the grid.
- Seasonal self cunsumption: Summer 10%, Autumn 8%, Winter 9%, Spring 8%.
Includes an inverter replacement at the 12-year mark. Replacement cost is $3,707 ($2,600 for the unit and $1,107 accounting for 3% inflation).
15kW Solar with 13kW String Inverter and 13.5kWh Tesla Powerwall 2
- System installation cost: $31,000 fully installed after solar rebate.
- Your first year's savings: $4,038.
- 10-year savings: $42,022.
- 20-year savings: $84,769.
- IRR: 13.55%.
- Payback time: 7 years and 6 months.
- Yearly self-consumption: 18% of solar used, 82% exported to the grid.
- Seasonal self cunsumption without batteries: Summer 10%, Autumn 8%, Winter 9%, Spring 8%.
Includes an inverter replacement at the 12-year mark. Replacement cost is $3,707 ($2,600 for the unit and $1,107 accounting for 3% inflation).
Seasonal Electricity Bills for 15kW Solar in Sydney
Summer 15kW Solar in Sydney
- Solar with batteries: $817 CREDIT.
- With solar: $777 CREDIT.
- Without solar: $358 DEBIT.
Autumn 15kW Solar in Sydney
- Solar with batteries: $536 CREDIT.
- With solar: $473 CREDIT.
- Without solar: $328 DEBIT.
Winter 15kW Solar in Sydney
- Solar with batteries: $434 CREDIT.
- With solar: $333 CREDIT.
- Without solar: $416 DEBIT.
Spring 15kW Solar in Sydney
- Solar with batteries: $830 CREDIT.
- With solar: $786 CREDIT.
- Without solar: $318 DEBIT.
| Month | kWh Produced |
|---|---|
| January | 2,264 kWh |
| February | 1,973 kWh |
| March | 1,786 kWh |
| April | 1,634 kWh |
| May | 1,271 kWh |
| June | 1,298 kWh |
| July | 1,388 kWh |
| August | 1,672 kWh |
| September | 2,016 kWh |
| October | 2,274 kWh |
| November | 2,201 kWh |
| December | 2,308 kWh |
20kW Solar Power Systems in Sydney
20kW Solar with 17kW String Inverter
- System installation cost: $20,000 fully installed after solar rebate.
- Your first year's savings: $4,977.
- 10-year savings: $50,632.
- 20-year savings: $98,748.
- IRR: 24.82%.
- Payback time: 4 years and 0 months.
- Yearly self-consumption: 7% of solar used, 93% exported to the grid.
- Seasonal self cunsumption: Summer 8%, Autumn 6%, Winter 7%, Spring 6%.
Includes an inverter replacement at the 12 year mark. Replacement cost is $4,848 ($3,400 for the unit and $1,448 for 3% inflation).
20kW Solar with 17kW String Inverter and 13.5kWh Tesla Powerwall 2
- System installation cost: $36,000 fully installed after solar rebate.
- Your first year's savings: $5,215.
- 10-year savings: $53,800.
- 20-year savings: $107,185.
- IRR: 14.82%.
- Payback time: 6 years and 10 months.
- Yearly self-consumption: 13% of solar used, 87% exported to the grid.
- Seasonal self cunsumption (without batteries): Summer 8%, Autumn 6%, Winter 7%, Spring 6%.
Includes an inverter replacement at the 12 year mark. Replacement cost is $4,848 ($3,400 for the unit and $1,448 for 3% inflation).
Seasonal Electricity Bills for 20kW Solar in Sydney
Summer 20kW Solar in Sydney
- Solar with batteries: $1,166 CREDIT.
- With solar: $1,129 CREDIT.
- Without solar: $358 DEBIT.
Autumn 20kW Solar in Sydney
- Solar with batteries: $786 CREDIT.
- With solar: $725 CREDIT.
- Without solar: $328 DEBIT.
Winter 20kW Solar in Sydney
- Solar with batteries: $667 CREDIT.
- With solar: $568 CREDIT.
- Without solar: $416 DEBIT.
Spring 20kW Solar in Sydney
- Solar with batteries: $1,176 CREDIT.
- With solar: $1,134 CREDIT.
- Without solar: $318 DEBIT.
| Month | kWh Produced |
|---|---|
| January | 3,019 kWh |
| February | 2,631 kWh |
| March | 2,381 kWh |
| April | 2,178 kWh |
| May | 1,694 kWh |
| June | 1,731 kWh |
| July | 1,850 kWh |
| August | 2,230 kWh |
| September | 2,688 kWh |
| October | 3,031 kWh |
| November | 2,934 kWh |
| December | 3,077 kWh |
