A tool does one sum. Solar Base does the whole job.
The STC count, the NMI, the meter alteration and the invoice, worked off one job record, with the last step left to you.
How the STC count is worked out
A solar system creates its certificates up front, for the power it is deemed to make until the Small-scale Renewable Energy Scheme ends in 2030. The count is the system's size, times the zone rating for the postcode it is installed in, times the years left in the scheme, rounded down to whole certificates.
Sunnier postcodes have higher ratings, so the same system creates more certificates in Darwin than in Hobart. Every new year takes one year off the deeming period.
STCs = kW × zone rating × deeming years, rounded down
Worked example
System24 × 550 W = 13.2 kW
Postcode3226 Ocean Grove, zone 4, rating 1.185
Installed2026: 5 deeming years
13.2 × 1.185 × 5 = 78.2178 STCs, $2,964 at $38.00
Questions installers ask
Why does the count drop every year?
The deeming period is the number of years left until the scheme ends in 2030. A system installed in 2027 gets four years where the same system installed in 2026 gets five.
Is the zone set by the install address or by my business?
The install address. The postcode where the panels go up sets the zone rating.
Does a battery on the same job add certificates?
A battery creates its own certificates under the Cheaper Home Batteries Program. Work them out with the battery STC calculator.
What price should I put in?
The price agreed with your trading agent, or the spot price on the day. The STC clearing house pays a fixed $40 ex GST, after a wait in its queue.
How long do I have to create the certificates?
Twelve months from the installation date, in the REC Registry. The Clean Energy Regulator suggests using a registered agent for any system within eight weeks of that deadline.