The words used for the solar STC are all over the place. Retailers say rebate, quotes say discount, forums say credit and some people ask for cash. Here is how they relate.
What an STC actually is
A Small-scale Technology Certificate is a certificate created by the Clean Energy Regulator’s registry after an eligible system is installed. One STC represents one megawatt hour of deemed renewable generation over the deeming period. Retailers are legally required to buy certificates, so STCs have a market price, which at the time of writing is roughly $38 to $40, with a $40 ceiling in the clearing house. Nobody pays a household a rebate cheque; the value comes from selling the certificates.
Why it feels like a discount
For most households, the installer or its agent creates the certificates and sells them. To make that possible you sign an assignment form that transfers the right to the STCs. In return, the installer reduces the price on your quote by the STC value, or by a slightly lower figure. So on paper you see a discount, and the “rebate” is already in the price. See how the discount appears on a quote.
When it is cash
Cash only appears if you keep the STCs and sell them yourself. You would pay the full price up front, then register, create the certificates and sell them through the market, typically ending up with cash a few weeks later. That route has paperwork and deadlines, and it rarely beats a good installer’s discount; see selling your own STCs.
A worked example: a 6.6 kW system in zone 3 earns about 45 STCs in 2026, worth about $1,710 to $1,800 at $38 to $40. Either that value is already off your quote, or you wait for cash. Use the STC calculator for your postcode.
What this means for you
- Treat the STC as part of the price, not a refund coming later.
- Check the quote states the number of STCs and the value used.
- Do not pay a deposit for a “rebate” before reading the assignment form.
- For tax treatment, see whether the solar rebate is taxable.
Read the homeowners pillar, and if you are an installer, see how STC trading works and our pricing.
Common questions
Is the discount GST-inclusive? Treat the quote as GST-inclusive and ask for a tax invoice showing the STC discount. Will the discount change if STC prices move before installation? Ask whether the installer fixed the value in the quote. Is the STC the only help? No; state schemes may add to it.