For solar professionals · free, no signup

STC calculator Australia: certificates and value by postcode

Enter the system size and postcode. You'll see the small-scale technology certificates (STCs) and their dollar value, with the maths shown.

Zone-aware STC deeming
STC value by postcode
STCs up to 1 MW since 1 Oct

Quoting this for a customer?

Model the whole site free: bill in, hourly load, every solar and battery size on one grid. No card.

Start free, no card

The System

Defaults are a 50 kW commercial system in Sydney, installed in 2027. The figures update as you type.

System size (kW)Up to 1 MW for installs from 1 October 2026 (100 kW before).

PostcodeSets the STC zone.

How this STC number is built

System size: 50.0 kW
Eligible capacity (first 100 kW): 50.0 kW
STC zone (postcode 2000): Zone 3 × 1.382
Deeming period (years to 2030): 4 years
Certificates: 276
Certificate price: $38.61
Estimated value: $10,656

STC value, estimate

Figures update as you type.

Standard STC rules cover systems up to 100 kW. From 100 kW to 1 MW, the mid-scale expansion covers installs from 1 October 2026.

Priced under the standard STC rules, up to 100 kW.

STC price used $38.61as at 9 Nov 2026Change

An independent estimate by Amperage, not a government tool. The final count comes from the REC Registry calculator and the registered agent. Certificate prices fluctuate.

Turn this into a sized proposal

Open Amperage with this STC estimate loaded into a project: every size and battery scenario against the real bill, and a branded proposal at the end.

For solar professionals. Free for 30 days, no card. Then $799 a month per company, or free for one project.

The maths

How STCs Are Calculated

STCs = eligible kW × the postcode's zone rating × the deeming period (years left until the scheme ends in 2030). Value is the count times the STC price. Sunnier northern zones earn more per kW.

The Factors

Each term in the figure above.

Zone rating1.622 (zone 1) to 1.185 (zone 4)

Deeming, up to 100 kWyears left to 2030

Deeming, 100 kW to 1 MWfixed 5 years (from 1 Oct 2026)

Above 1 MWLGCs on the balance

Certificatesrounded down

Over 100 kW: The New Rule

What changed on 1 October 2026.

Before 1 Oct 2026STCs to 100 kW, LGCs above

From 1 Oct 2026STCs up to 1 MW, fixed 5‑year deeming

RegulationsMid‑scale Solar, registered 17 Sep 2026

Quoted before October?Re‑run it

How The STC Rebate Works

How STCs Work

Small-scale Technology Certificates are the federal upfront discount on solar under the Small-scale Renewable Energy Scheme. For installs from 1 October 2026 they cover up to 1 MW of site capacity (100 kW before), for the power generated until the scheme ends in 2030. The certificates go to a registered agent, and the value comes back as a point of sale discount in the quote.

What Sets The Number

System size (the first 100 kW under the older rules, the whole system from 100 kW to 1 MW), the postcode zone rating (1.622 in the far north to 1.185 in the south) and the deeming period. Deeming is the years left until 2030, so the count steps down each January; the mid-scale band is a fixed five years.

A Worked Example

A 30 kW system in Sydney is Zone 3, rated 1.382. Installed in 2026 it deems five years: 30 × 1.382 × 5 is about 207 certificates, close to $8,100 off the install price at roughly $39 each. The panels and inverter must be on the Clean Energy Council lists, and a CEC-accredited installer must sign off the job.

Questions

Frequently Asked Questions

How many STCs will a solar system earn?

STCs = eligible kW × the postcode zone rating × the deeming period. For installs from 1 October 2026, a system up to 1 MW of site capacity earns certificates on the whole system: years remaining to 2030 up to 100 kW, or a fixed 5-year deeming from 100 kW to 1 MW (Mid-scale Solar Regulations, registered 17 September 2026). Before that date, only the first 100 kW earned STCs. The calculator prices the 100 kW to 1 MW band automatically.

Can a system over 100 kW claim STCs?

Yes, if it is installed from 1 October 2026. Under the mid-scale rules registered on 17 September 2026, a system above 100 kW and up to 1 MW creates upfront STCs on the whole system at a fixed 5-year deeming period. Above 1 MW the first 1 MW earns STCs and the balance earns Large-scale Generation Certificates (LGCs). Before that date, the first 100 kW earns STCs and the balance earns LGCs.

How much is an STC worth?

STC prices float beneath the $40 clearing-house cap. The calculator starts from the current market default. Change it under More options to match your quote.

What is an STC zone?

Australia has four zones, split by solar irradiance. Sunnier northern zones earn a higher multiplier per kW than cooler southern zones.

Related Calculators And Guides

All solar incentives

VEEC Calculator for VictoriaVEECs for commercial solar in Victoria.LGC Calculator for AustraliaLGC revenue above the STC line.NSW Battery Rebate Calculator (PDRS)PRCs and the upfront discount for NSW batteries.Cheaper Home Batteries CalculatorBattery STCs under the federal program.Commercial Solar CalculatorSize, incentives and savings from your spend.Solar Payback CalculatorYears to pay back, by state.Solar System Size CalculatorThe kW that fits a warehouse, office or shop.

Guides

STC, VEEC And LGC ComparedThe three commercial solar incentives side by side, and which one applies.STC 1 MW ExpansionWhat the 1 MW expansion changes for commercial solar quotes from October 2026.Incentive StackingWhich solar and battery incentives can be claimed on one system.

Then model the whole site.

Bill in, every solar and battery size on one grid, STCs and LGCs split for you, a branded proposal out. About 10 minutes to a credible estimate.

Start free, no card Book a Demo