Australian homeowners considering rooftop solar or a home battery system are facing a significant reduction in federal government incentives from 1 January 2027. The Clean Energy Regulator (CER) confirms that the Small-scale Technology Certificate (STC) scheme, which provides an upfront discount on installation costs, will see its deeming period shorten for solar PV systems and the STC factor decrease for batteries. This change is set to reduce the federal rebate by approximately 20% for solar panels and 16% for batteries, potentially costing households hundreds of dollars if they delay installation.
For a typical 6.6kW solar PV system, this reduction could translate to around $340 less off the upfront cost, while a larger 10kW system might see a decrease of approximately $560.
What’s Changing with Your Solar Rebate?
The federal solar rebate is not a direct cash payment but an upfront discount facilitated by Small-scale Technology Certificates (STCs). These certificates are generated based on the expected renewable electricity your system will produce over a ‘deeming period’—the number of years until the Small-scale Renewable Energy Scheme (SRES) concludes in 2030.
Currently, for systems installed in 2026, the deeming period is five years. However, from 1 January 2027, this period will drop to four years, reducing the number of STCs your system can claim. This annual step-down is a scheduled part of the scheme’s phase-out towards 2030.
“The deeming period drops by one year every 1 January. The scheme is legislated to end after 2030, so each year your system is credited with one less year of generation.”
Similarly, the federal Cheaper Home Batteries Program, which also operates through STCs, will see its STC factor decrease. For eligible batteries installed in the latter half of 2026, the STC factor is 6.8 per kilowatt-hour (kWh) of usable capacity. From 1 January 2027, this factor will fall to 5.7, representing about a 16% cut in the battery rebate.
The Financial Impact on Your Installation
To illustrate the potential financial impact, consider the following estimates based on an indicative STC market value of AUD$38, which can fluctuate with market dynamics.
| System Type | Capacity (kW/kWh) | STCs (2026 Estimate) | Rebate Value (2026 @ $38/STC) | STCs (2027 Estimate) | Rebate Value (2027 @ $38/STC) | Estimated Reduction |
|---|---|---|---|---|---|---|
| Solar PV (Zone 3) | 6.6 kW | 45 STCs | ~$1,710 AUD | 36 STCs | ~$1,368 AUD | ~$342 AUD |
| Solar PV (Zone 3) | 10 kW | 68 STCs | ~$2,584 AUD | 54 STCs | ~$2,052 AUD | ~$532 AUD |
| Home Battery | 10 kWh | 68 STCs (factor 6.8) | ~$2,584 AUD | 57 STCs (factor 5.7) | ~$2,166 AUD | ~$418 AUD |
| Home Battery | 13.5 kWh | 91.8 STCs (factor 6.8) | ~$3,488 AUD | 76.95 STCs (factor 5.7) | ~$2,924 AUD | ~$564 AUD |
Note: STC calculations are indicative and depend on specific system components, installer pricing, and the exact postcode zone rating. Zone 3 applies to major population centres like Sydney, Brisbane, and Canberra.
The Urgency: Installation Date is Key
It is crucial for homeowners planning a solar or battery installation to understand that the rebate amount is determined by the system’s installation and certification date, not the date the contract is signed. To secure the higher 2026 rebate rates, your system must be fully installed and commissioned before 31 December 2026. Installers often experience increased demand towards the end of the year, so acting promptly is advisable to ensure your project is completed in time.
This annual reduction means that for every year you delay, the federal incentive for new solar installations diminishes. For a comprehensive overview of available support, refer to our guide on Your 2026 Guide: Claim Up To $15,000 in Energy Rebates Across Australia.
Maximising Your Solar Savings in 2026
Beyond the federal STC scheme, various state-based incentives and competitive electricity plans can further reduce the cost of solar ownership and maximise your return on investment. Choosing the right solar panels can also significantly impact your system’s efficiency and long-term savings. For more information on selecting components, see our article on Best Solar Panels in Australia 2026: Get Up to 25% Efficiency & Max. $15,000 in Rebates.
With feed-in tariffs remaining low in many regions, installing a home battery alongside your solar PV system becomes increasingly attractive for optimising self-consumption and reducing reliance on the grid during peak times. Evaluating your electricity plan to complement your solar setup is also vital for maximising savings. Consider reviewing Solar Households: Slash Your 2026 Bills by $1,000+ with These Electricity Plans.
If you have been contemplating an investment in solar energy or battery storage, the impending rebate reduction on 1 January 2027 serves as a clear financial incentive to act sooner rather than later. Obtain quotes from reputable installers now to ensure your system can be installed and certified before the deadline.
The Road Ahead for Renewable Energy Incentives
The Small-scale Renewable Energy Scheme is designed to gradually phase out, with the deeming period reducing annually until the scheme’s conclusion at the end of 2030. While the incentives are shrinking, the fundamental economic case for solar in Australia remains strong, driven by falling technology costs and rising electricity prices. The federal government’s ongoing support, even if diminishing, continues to make renewable energy more accessible for households and businesses across the country.
For businesses, a separate but related change came into effect on 1 October 2026, expanding SRES eligibility to solar PV systems between 100 kW and 1 MW, which now receive a fixed five-year deeming period for STC creation. This aims to provide upfront cost reductions for larger commercial installations, but it does not alter the scheduled annual reduction for smaller, residential systems.