Calculator

STC calculator

Postcode, system size, install year. The number of certificates, the maths behind it, and what they are worth at today's rate.

PostcodeZone (auto from postcode, or pick)System size (kW)Install yearSTC price ($)

—STCs

FormulakW × zone rating × years

Zone—

Value at your price—

Rounded down to whole certificates, as the Clean Energy Regulator does. Indicative only: eligibility, the 100 kW cap and the registry's calculator decide the final count. Today's rate is $38.50 per STC.

How the STC count is worked out

Small-scale Technology Certificates are deemed up front for the remaining life of the scheme. Three inputs decide the number: the system's rated capacity in kilowatts, the zone rating for the postcode, and the deeming period for the year of installation.

STCs = kW × zone rating × deeming years, rounded down.

Zone ratings

Zone	Rating	Typical areas
1	1.622	Inland and northern Australia, e.g. Alice Springs
2	1.536	Darwin and parts of the north
3	1.382	Sydney, Brisbane, Perth, Adelaide, Canberra, Cairns, Townsville and most regional centres
4	1.185	Melbourne, Geelong, Hobart, Launceston and the southern coast

Postcode decides the zone, not the nearest city. The calculator uses the Clean Energy Regulator's postcode zone table (137 ranges).

Deeming period

The scheme ends on 31 December 2030, so the deeming period is 5 years for 2026 installs, 4 for 2027, 3 for 2028, 2 for 2029 and 1 for 2030. Every January the same system earns fewer certificates, which is why December installs are worth lodging before the year turns. See the deeming guide.

Capital cities, 6.6 kW, 2026

City	Zone	STCs
Sydney	3	45
Melbourne	4	39
Brisbane	3	45
Perth	3	45
Adelaide	3	45
Hobart	4	39
Canberra	3	45
Darwin	2	50
Alice Springs	1	53
Cairns	3	45
Townsville	3	45
Gold Coast	3	45
Newcastle	3	45
Geelong	4	39
Wollongong	3	45
Launceston	4	39

From the desk: quote the STC count on the proposal as "estimated", and recalculate on the day of installation. A December quote installed in January loses a deeming year.

What the certificates are worth

Multiply the count by the buy price. Energy Merchants publishes its rate every trading morning, locks it when a complete claim is lodged, charges no fees and settles within 24 hours for established partners. For battery certificates use the battery STC calculator.

Questions

Calculator questions

How many STCs does a 6.6 kW system get in 2026?

In zone 3 (Sydney, Brisbane, Perth, Adelaide, Canberra): 6.6 × 1.382 × 5 = 45.6, so 45 STCs. In zone 4 (Melbourne, Hobart): 6.6 × 1.185 × 5 = 39.1, so 39. In 2027 the deeming period drops to 4 years, so the same systems earn 36 and 31.

Which zone is my postcode in?

Type your postcode into the calculator; it uses the Clean Energy Regulator postcode zone table. Zone 1 is the sunniest (inland and northern Australia), zone 4 the least (Melbourne, Hobart and the southern coast). Most capitals are zone 3.

Why does the calculator round down?

The Clean Energy Regulator rounds the result down to a whole number of certificates. A result of 45.6 is 45 STCs, not 46.

Is the dollar value what I will actually be paid?

It is the number of certificates multiplied by the price you enter. Energy Merchants publishes its buy price daily and pays that price on every certificate with no fees, so for our partners the figure is the amount settled. Other buyers may deduct fees.

What is the 100 kW cap?

Systems over 100 kW are not small-scale and create LGCs instead of STCs. The calculator caps the input at 100 kW.

Turn the number into money, tomorrow.

Trade your STCs with Energy Merchants: published rate, zero fees, 24-hour settlement.

Start trading Talk to the desk