If the government will always sell you an STC for $40, why would anyone sell for less? The short answer is that the Clearing House is slow and capped, and the market pays for speed.
How the Clearing House sets the ceiling
The Clean Energy Regulator runs the STC Clearing House. Liable entities, mostly electricity retailers, can buy certificates from it at $40 each. Because the regulator will supply any quantity at that price, the market can never sustainably trade above it. That is the ceiling. See spot versus Clearing House.
Why the market trades under it
Time. The Clearing House sells to buyers in the order requests were placed, and buyers there wait for certificates to come off the queue. Open-market buyers can have certificates sooner. A buyer who needs certificates now pays closer to $40; one who is relaxed pays less.
Cost. Registry transfers, compliance checks and administration have a price.
Risk. Some certificates face questions later, through audit or validation.
Supply. When certificate creation outruns what liable entities need, the surplus pushes spot down, and the Clearing House queue grows. At the time of writing, STC spot has been roughly $38 to $40, the 2026 small-scale technology percentage is reported at about 11.67%, and battery certificates are adding supply, see oversupply and battery certificates.
What the gap tells you
- Under 50 cents. The market is balanced.
- A dollar or more. Supply is heavy or buyers are cautious.
- Wide and persistent. Often a sign of a surplus that will take quarters to clear.
Why your rate is lower again
Spot is the market’s price between wholesale parties. The rate a trader pays you reflects its margin and your settlement terms. It can be well under spot with slow payment or close to it with fast, and fees can hide the difference. Read how traders earn their margin.
What this means for installers
Use the ceiling to sense-check any quote: nobody should be offering above $40. Then compare net dollars after all deductions. Energy Merchants publishes its daily buy rate on the pricing page, with no fees and locking on lodgement of a complete claim. The STC trading overview explains how a claim becomes cash, and what an STC is worth turns the rate into dollars per system.