How long does a battery take to pay back in Melbourne?
Updated 6 November 2026
Short answer: for most Melbourne homes with solar, a 13.5 kWh battery pays back in about 9–11 years. On a Midday Power Saver plan it can be closer to 6–8 years, because the battery can fill up free in the middle of the day.
The tables below are worked out with our calculator. For each daily usage we show the battery size with the shortest payback. Assumptions: 34c/kWh usage rate, 3.3c feed-in, a third of use in the daytime, prices after the May–December 2026 rebate.
With 6.6 kW solar, standard plan
| Daily use | Best-payback size | Saving / year | Price after rebate | Payback |
|---|---|---|---|---|
| 10 kWh | 10 kWh | $583 | $8,484 | 14.6 yrs |
| 15 kWh | 10 kWh | $807 | $8,484 | 10.5 yrs |
| 20 kWh | 13.5 kWh | $1,089 | $9,791 | 9 yrs |
| 25 kWh | 13.5 kWh | $1,089 | $9,791 | 9 yrs |
| 30 kWh | 13.5 kWh | $1,070 | $9,791 | 9.2 yrs |
| 40 kWh | 10 kWh | $787 | $8,484 | 10.8 yrs |
With 6.6 kW solar, Midday Power Saver plan
| Daily use | Best-payback size | Saving / year | Price after rebate | Payback |
|---|---|---|---|---|
| 10 kWh | 10 kWh | $807 | $8,484 | 10.5 yrs |
| 15 kWh | 10 kWh | $1,117 | $8,484 | 7.6 yrs |
| 20 kWh | 13.5 kWh | $1,508 | $9,791 | 6.5 yrs |
| 25 kWh | 20 kWh | $2,017 | $12,822 | 6.4 yrs |
| 30 kWh | 20 kWh | $2,228 | $12,822 | 5.8 yrs |
| 40 kWh | 20 kWh | $2,184 | $12,822 | 5.9 yrs |
No solar, Midday Power Saver plan (battery charges free 11am–2pm)
| Daily use | Best-payback size | Saving / year | Price after rebate | Payback |
|---|---|---|---|---|
| 10 kWh | 10 kWh | $807 | $8,484 | 10.5 yrs |
| 15 kWh | 10 kWh | $1,117 | $8,484 | 7.6 yrs |
| 20 kWh | 13.5 kWh | $1,508 | $9,791 | 6.5 yrs |
| 25 kWh | 20 kWh | $2,017 | $12,822 | 6.4 yrs |
| 30 kWh | 20 kWh | $2,211 | $12,822 | 5.8 yrs |
| 40 kWh | 20 kWh | $2,055 | $12,822 | 6.2 yrs |
What makes payback faster
- Using most of your power in the evening and overnight.
- A Midday Power Saver plan, so the battery is full every day even in winter.
- Charging an electric car from the battery or in the free hours.
- Staying at or under 14 kWh, where the rebate is highest.
What makes it slower
- Someone home all day using solar directly.
- A small solar system and no free midday plan.
- Buying a 30–50 kWh battery for a home that only uses 15–20 kWh a day.
Questions people ask
How much does a battery save per year in Melbourne?
A home using 20 kWh a day with 6.6 kW of solar saves about $1,089 a year with a 13.5 kWh battery on a standard plan. Without solar but on a Midday Power Saver plan the same battery saves about $1,508.
What size battery do I need for 20 kWh a day?
Usually 13.5 kWh. Above 14 kWh the rebate drops and most homes using 20 kWh a day cannot use the extra storage every night unless they also charge an electric car.