From 1 October 2026, the commercial solar rebate threshold increases 10x, from 100 kW to 1,000 kW.
If your business previously stopped at around 99 kW because going bigger meant leaving the STC scheme, the calculation has changed.
From 1 October 2026, eligible commercial solar systems above 100 kW and up to 1,000 kW can access Small-scale Technology Certificates (STCs) through the expanded Small-scale Renewable Energy Scheme. The previous threshold was 100 kW.
For businesses with higher daytime energy use, this creates more room to size a commercial solar system around what the site actually needs while still accessing eligible STC support.
For one 199.5 kW commercial system we recently assessed, the indicative project cost was around $233,000 before incentives. Combining federal STCs with Victoria’s commercial solar incentive brought the indicative net cost down to around $133,000.
That’s a real FutureNRG assessment. This guide covers what has changed, who may qualify and what businesses should consider when looking at a larger solar system.
What’s changing for commercial solar?
Until 30 September 2026, solar PV systems had to be 100 kW or smaller to access STCs through the Small-scale Renewable Energy Scheme.
From 1 October, the scheme expands to eligible mid-scale solar systems up to 1,000 kW. Eligible systems in the newly expanded range receive a fixed five-year STC deeming period. STC applications for these systems are expected to open in mid-to-late November 2026.
So while businesses have always been able to install larger solar systems, the upfront STC incentive can now apply to a much larger system size.
That is the important change.
Why the old 100 kW line mattered
A 100 kW system can be substantial, but many commercial, industrial and agricultural sites have much higher daytime electricity demand.
Cold storage facilities, irrigation systems, factories, warehouses and school campuses can all have enough daytime load to support larger solar systems.
Under the previous SRES rules, moving above 100 kW meant leaving the STC pathway. That could influence businesses to keep projects around the old threshold even when a larger system better matched the site’s energy needs.
The new 1,000 kW threshold gives businesses much more room to assess system size around electricity use, available space, network capacity and project economics.
Is your business eligible?
For the newly expanded part of the SRES, there are a few practical requirements to consider:
- The solar PV system must fall within the expanded mid-scale range, above 100 kW and up to 1,000 kW.
- The eligible mid-scale system must be installed from 1 October 2026.
- The system must meet relevant SRES design, installation and compliance requirements.
- The designer and installer must hold the required Solar Accreditation Australia accreditation.
- Solar panels and inverters must meet the applicable approved-product requirements.
- Network connection, electrical and other relevant approvals still apply.
Already have solar installed? The Clean Energy Regulator is still publishing further guidance covering existing systems, extensions and upgrades. So if you are considering adding capacity to an existing system, get the site assessed before building an incentive calculation around it.
How much roof space will you need?
It depends on the system, roof layout and equipment.
As a current Victorian Government guide, a 100 kW commercial solar system typically requires around 450 m² to 600 m² of clear roof area. Larger systems need to be assessed against usable roof or ground space, structural suitability, orientation and site conditions.
A real example: 199.5 kW before and after incentives
Here’s a project we recently assessed:
Every site is different. Actual project costs and available incentives depend on system design, energy use, network requirements, certificate values, VEU eligibility and installation conditions.
Combine federal and Victorian solar incentives
Victorian businesses may have another incentive available through the Victorian Energy Upgrades program.
The Commercial and Industrial Solar activity provides upfront discounts for eligible solar PV systems between 30 kW and 200 kW. The Victorian Government also confirms that eligible projects may be able to claim other renewable energy incentives alongside the VEU discount.
That overlap is particularly relevant for eligible systems between 100 kW and 200 kW, where businesses can now assess the expanded federal STC support alongside the Victorian incentive.
In the right applications, we’ve modelled payback periods under five years, with some projects getting close to three years once available incentives are included.
Actual payback depends on the site’s electricity use, system design, installation cost, certificate values and available incentives.
A bigger rebate doesn’t remove every hurdle
Larger commercial solar systems still need proper technical and network planning. System design needs to consider daytime electricity use, roof or ground space, network capacity, export limits and future energy demand.
For Victorian C&I projects, the VEU requirements also include connection to the relevant distribution network and compliance with the applicable network connection contract. The expanded STC threshold can improve the upfront economics. The system still needs to be properly sized around how your business uses energy.
Is now the time to look again?
It may be worth reassessing commercial solar if:
- You use significant electricity during the day
- You previously installed around 99 kW to stay within the old STC threshold
- You considered a larger system before but decided the numbers did not stack up
- Your business has grown and your electricity demand has increased
- You are planning a commercial solar project from October 2026 onwards
With the threshold increasing from 100 kW to 1,000 kW, the numbers for a larger system may look different now.
Get your site assessed
We can put together an initial assessment for your site at no cost.
That covers system sizing, available incentives, estimated energy savings and indicative payback based on your business and current scheme requirements.
Whether you’re in metro Melbourne or regional Victoria, we can assess what commercial solar could look like for your site.
Get your free commercial solar assessment or learn more about our commercial solar systems.
FAQs
What is an STC?
A Small-scale Technology Certificate, or STC, is created when an eligible renewable energy system is installed. The certificates have a financial value and are commonly assigned to an installer or agent in exchange for an upfront reduction in the cost of the system.
Is the increase to 1,000 kW confirmed?
Yes. The regulations have been amended to expand SRES eligibility for solar PV systems from 100 kW to 1,000 kW. The changes apply to eligible mid-scale solar systems installed from 1 October 2026.
When can STCs be claimed for systems above 100 kW?
The changes apply to eligible systems installed from 1 October 2026. Applications for mid-scale STCs are expected to open in mid-to-late November 2026.
Can I combine the federal and Victorian solar incentives?
Eligible Victorian projects may be able to access both federal renewable energy incentives and the Victorian Energy Upgrades discount, provided the project meets the requirements of each scheme.
The VEU Commercial and Industrial Solar activity covers eligible systems between 30 kW and 200 kW.
I already have a 99 kW system. Is it worth expanding?
It may be worth reassessing if your business has enough electricity demand to use additional solar.
The expanded SRES includes provisions for upgrades to existing systems, but the number of STCs available depends on the specific installation and the capacity being added. FutureNRG can assess the existing system before you plan around a particular rebate amount.
How much roof space do I need for commercial solar?
It depends on the system size, panels, roof layout and site conditions. As a guide, the Victorian Government estimates that a 100 kW system typically requires around 450 m² to 600 m² of clear roof area.
