With the increasing interest in solar energy and the growing demand for energy independence, battery storage is becoming a key component of solar energy systems. For homeowners in New South Wales (NSW) in 2025, adding a solar battery to your system can drastically improve your energy savings, offer backup power, and allow you to participate in Virtual Power Plants (VPPs) for added financial benefits.
Here is a detailed explanation of how battery storage savings are calculated, specifically in NSW in 2025.
What Do We Calculate in a Battery Estimate?
Battery Size Recommendation – based on your energy needs
Federal Government Rebate – 30% in 2025
Extra Bill Savings – how much more you save with a battery
Payback Period – how long until it pays off
VPP Incentives – potential annual credits if you join a Virtual Power Plant
What Info Do You Need to Provide?
Whether you want a battery – Yes/No
Your electricity usage patterns – Day/Night usage
Your solar system size – existing or planned
Step-by-Step Battery Savings Calculation
Recommend a Battery Size
The first step is determining the size of the battery you need based on your energy consumption and your requirement for backup power during outages.
Average daily usage – Let’s assume your household uses around 10–12 kWh of electricity per day (especially in the evening when solar power is not available).
Backup power requirement – You also want a battery that can provide sufficient power in case of blackouts.
Based on this usage, we recommend a 10 kWh battery, which can store enough energy to power essential appliances (like lights, fridge, fans) during an outage.
Examples of good battery options in the market
Sigenergy SigenStor (5kWh–48kWh, scalable)
Sungrow Battery (9.6kWh–25.6kWh, scalable)
Tesla Powerwall 3 (13.5 kWh)
Enphase IQ Battery (5kWh–15kWh, modular)
Anker SOLIX X1 (up to 13.5 kWh)
Federal Battery Rebate (Cheaper Home Batteries Program) –
Provides up to 30% in rebates on approved batteries
Available Australia-wide, including NSW
Battery Cost After Rebate
Now, let’s calculate the total out-of-pocket cost for the battery after applying the rebate.
Retail price of the battery system – $12,000 (This includes the battery, installation, and other setup costs).
Rebate applied – Subtract the applicable rebate of $3,000 from the retail price.
So, the final out-of-pocket cost for the battery would be –
Final Cost = Retail Price − Rebate = $12,000 − $3,000 = $9,000
This means you would pay $9,000 for the battery installation after the rebate.
Estimate Extra Annual Savings
Once you install a battery, your electricity consumption from the grid decreases, since you are storing solar energy during the day for use at night. This can lead to significant savings.
Grid usage reduction – With the battery in place, your grid consumption drops by 90%. In practical terms, that means you will be using mostly your own solar energy, and the battery stores extra energy for when you need it (especially at night).
Additional savings – On top of savings from your solar system (let’s assume you save around $1,400/year from solar alone), having a battery can further save you about $600–$900/year on your electricity bill, as you are using stored energy instead of purchasing from the grid.
Example:
Additional savings from battery – $600–$900
Solar savings – $1,400
Total savings – $1,400 + $800 (average battery savings) = $2,200/year
Payback Period with Battery
The payback period is the amount of time it takes to recover the cost of your battery installation through the savings you make on electricity bills.
Final cost of battery: $9,000 (after rebate)
Total annual savings: $2,200 (from solar and battery)
To calculate the payback period, simply divide the total battery cost by the total savings –
Payback Period = Final Cost/Annual Savings = $9000/ $2200 = 4 years.
Your payback period is approximately 4 years. This means that after 4 years, your battery will have paid for itself through the savings on your electricity bills. After that, you can enjoy free (or very low-cost) electricity and even start earning money through programs like VPP
Additional Potential Earnings with VPP Participation
If you participate in a Virtual Power Plant (VPP), you can earn extra income by supplying excess energy back to the grid during peak demand times.
Earnings from VPP – Depending on the VPP program, you could earn another $300–$500/year for exporting surplus energy to the grid.
Estimated total earnings from VPP – Let’s assume you earn an additional $400/year from your VPP participation.
This further reduces your payback period and increases your return on investment.
Please note – This is an approximate calculation. For an exact fee and personalized quote, feel free to contact us.
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