Why This Matters
The federal battery rebate drops approximately 10% on January 1, 2026. For a typical 10kWh battery, that's about $340 less in your pocket.
But here's where people get caught out: the rebate rate isn't determined by when you order or pay. It's determined by a specific date that many people misunderstand.
Critical Warning
If you ordered a battery in November 2025 expecting the 2025 rebate rate, but installation slips to January 2026, you'll receive the lower 2026 rate. The order date is irrelevant.
Installation vs Commissioning: What's the Difference?
Physical Installation
When the battery is mounted, wired, and physically set up at your property.
- Battery mounted on wall or floor
- Electrical connections made
- Conduit and wiring run
- May take 1-3 days
This is NOT the date that matters for rebates
Commissioning
When the system is tested, certified as safe, and officially "switched on."
- System tested for safety
- Functionality verified
- Certificate of compliance signed
- Usually same day or shortly after install
THIS is the date that determines your rebate
The Official Definition
According to the Clean Energy Regulator, the installation date is "the date the electrical certificate of compliance (or equivalent) is signed." This certificate confirms the system has been tested as capable of storing or discharging energy.
In practice, this means the commissioning date (when testing is completed and the certificate is issued) is what matters - not when physical work started.
Which Date Determines Your Rebate Rate?
The Answer
The date on your electrical certificate of compliance - specifically the test date showing when the system was verified as capable of storing or discharging energy.
What Doesn't Matter
- Quote date - Irrelevant. A November quote doesn't lock in November rates.
- Order date - Irrelevant. Ordering before December 31 doesn't guarantee 2025 rates.
- Deposit date - Irrelevant. Paying money doesn't secure the rate.
- Physical installation start - Irrelevant. Work can begin in 2025 but certificate in 2026 = 2026 rate.
What Does Matter
- Certificate of compliance date - This is the controlling date
- The date the system is tested - Must be verified as functional
- When STCs are generated - Tied to the compliance certificate
Example
You get a quote on November 15, 2025. Physical installation happens December 28, 2025. But the electrician doesn't sign off the certificate until January 3, 2026 (maybe they're on holiday).
Result: You get the 2026 rebate rate, even though you ordered and installed in 2025.
The January 2026 Rate Drop
The federal battery rebate works through Small-scale Technology Certificates (STCs). The number of STCs per kWh drops each year:
| Year | STCs per kWh | ~Rebate per kWh | ~10kWh Battery |
|---|---|---|---|
| 2025 | 9.3 STCs | ~$372/kWh | ~$3,720 |
| 2026 | 8.4 STCs | ~$336/kWh | ~$3,360 |
| 2027 | 7.4 STCs | ~$296/kWh | ~$2,960 |
| 2028 | 6.5 STCs | ~$260/kWh | ~$2,600 |
| 2029 | 5.6 STCs | ~$224/kWh | ~$2,240 |
| 2030 | 4.7 STCs | ~$188/kWh | ~$1,880 |
The 2025 to 2026 Drop
From 9.3 to 8.4 STCs represents approximately a 9.7% reduction. For a typical 10kWh battery, that's $330 less rebate. For a 13.5kWh Tesla Powerwall, it's about $445 less.
Worth noting: the battery rebate declines more slowly than the solar panel rebate (which drops ~16.7% annually). So while timing matters, it's not as dramatic as solar.
Typical Installation Timeline
Understanding the full timeline helps you plan for the rebate you want:
Quote & Decision
Getting quotes, comparing options, making your decision
Scheduling & Supply Chain
Waiting for installer availability and equipment delivery. This is the bottleneck - most installers are booked 2-4 months out.
Physical Installation
Actual on-site work to mount and wire the battery
Commissioning
Testing, certification, and signing the compliance certificate. This date determines your rebate.
STC Processing
Installer claims STCs from Clean Energy Regulator. Rebate already applied to your invoice.
Current Wait Times (November 2025)
The Clean Energy Regulator reports: "Most installers are booked out for 2-4 months. Some are scheduling into early 2026."
If you haven't ordered yet, getting a December 2025 commissioning date will be very difficult.
What If Installation Is Delayed?
If your installation slips from 2025 into 2026, there are no extensions, exemptions, or appeals. The rules are absolute.
Common Causes of Delays
- Installer backlog - High demand exceeding capacity
- Supply chain issues - Battery or inverter not in stock
- Weather - Can't work in rain or extreme heat
- Electrician availability - For final sign-off
- Holiday periods - December/January closures
- Site complications - Unexpected electrical or structural issues
Your Options If Delayed
- Accept the lower rebate - Still significant savings, just $300-400 less
- Negotiate with installer - Some offer fixed-price guarantees covering rebate changes
- Cancel and wait - Battery prices are falling, may offset rebate drop (but uncertain)
Who Bears the Risk?
Check your contract carefully. Some installers quote "after rebate" prices that assume a specific STC rate. If installation is delayed through no fault of yours, who pays the difference? Get this in writing.
Required Documentation
Your installer must provide specific documentation proving the commissioning date. This protects both of you.
Key Documents
- Certificate of Electrical Compliance - Shows the test date (the critical date)
- Geotagged photos - Time-stamped images of installation
- Serial number photos - Proving which specific battery was installed
- Installer selfies - At setup, mid-install, and commissioning (yes, really)
- Tax invoice - Showing system details and cost
- STC assignment form - Authorizing installer to claim certificates
Photo Metadata Requirements
Photos must include embedded metadata showing date, time, and GPS location. The Clean Energy Regulator can verify this metadata to confirm when commissioning occurred. Photos without proper metadata may trigger audits or rejections.
Keep Your Documentation
Request copies of all documentation from your installer. The Regulator can request verification for up to 5 years. Having your own copies protects you.
State-Specific Date Requirements
Some state programs have additional timing requirements beyond the federal rules:
Victoria
For approved Solar Homes loan recipients: Installation must be completed within 120 days of loan approval. Final deadline December 31, 2025 - no extensions.
Tasmania
For approved Energy Saver Loan recipients: Installations must be settled by November 30, 2025. Scheme is now closed to new applications.
Western Australia
Battery must be installed (purchased and commissioned) from July 1, 2025 onwards. Rebates cannot be applied retrospectively for earlier purchases.
ACT
Solar installations approved under the old zero-interest scheme must be completed by November 1, 2025. New battery purchases under 3% scheme have no deadline.
Tips to Secure the 2025 Rebate Rate
If you want the higher 2025 rate, here's what to do:
- Act immediately
Most installers are booked 2-4 months out. If you're reading this in November 2025, getting commissioned before December 31 will be challenging.
- Get a realistic installation date in writing
Ask the installer: "What is your earliest available commissioning date?" Get this confirmed in writing.
- Confirm who bears rebate risk
If the installer quotes a price assuming 2025 STCs but delays push you to 2026, who pays the $300+ difference?
- Choose stock items
Batteries that are in stock will be installed faster than special orders. Ask what the installer has available now.
- Be flexible with dates
If the installer has a cancellation on December 23, can you accommodate? Being flexible may get you commissioned earlier.
- Understand the actual difference
For a 10kWh battery, the 2025 vs 2026 difference is ~$330. Significant, but not worth accepting a rushed, low-quality installation.
Perspective Check
The rebate drops ~10% from 2025 to 2026. But battery prices are also falling. A well-sized, well-installed battery in January 2026 will still be an excellent investment. Don't sacrifice quality for a few hundred dollars.
Frequently Asked Questions
If I order before December 31, do I get the 2025 rate?
No. The order/quote date is irrelevant. Only the commissioning date (certificate of compliance date) matters. If commissioning happens in 2026, you get 2026 rates.
Can my installer "back-date" the certificate to December 2025?
No, and don't ask them to. This would be fraud. Photos include GPS and timestamp metadata that regulators verify. Penalties apply to both installer and customer for false claims.
What if physical installation finishes in December but the electrician doesn't sign off until January?
The certificate date is what matters. If signed in January, you get January rates. Coordinate with your installer to ensure sign-off happens before year-end if that's important to you.
Is there any way to appeal or get an extension?
No. The STC system is based on objective dates with no discretionary extensions. The certificate date is the certificate date, full stop.
Does commissioning date affect state rebates too?
Yes, state programs typically have their own timing requirements. Victoria, Tasmania, WA, and ACT all have specific date cutoffs for their respective programs. Check each state's rules.
How long does commissioning take after physical installation?
Usually 1-5 days. Often same-day if the electrician is available. The risk is holiday periods (Christmas/New Year) when electricians may be unavailable for sign-off.
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