The STC price has a short and instructive history. It began as an unsettled market, found a ceiling, and for most of the last decade has traded in a narrow band just beneath it. If you have only ever quoted solar jobs in the last few years, that stability can look like a law of nature. It is not. It is the result of a particular scheme design, and knowing how it works tells you when to expect calm and when to expect noise.
This article walks through the shape of the price history, not a tick-by-tick chart. For an exact figure on a given day, use the Clean Energy Regulator (CER) or a trader’s published rate. We do not reproduce figures we cannot verify, and every number below is either a scheme rule or flagged as approximate.
The ceiling that anchors everything
The most important fact is the STC Clearing House. The CER allows certificate holders to sell at a fixed $40 per STC, ex GST. Because holders can always do that, nobody should accept less than $40 in the long run unless they are buying speed or certainty. That makes $40 a ceiling for the market price.
The catch is the queue. Clearing house sales are processed in order, and when supply is heavy the wait can stretch to many months. So the market price sits below $40 by an amount that reflects how much faster and more reliable a trader’s payment is than waiting in line. Our explainer on the STC price and the clearing house and what an STC is worth cover the gap in more detail.
Phase one: the early scheme
When the Small-scale Renewable Energy Scheme began, rooftop solar demand surged and the market was learning how to price a certificate. Prices moved a great deal as supply outran what the market expected, and the long deeming period (15 years of expected generation for early installs) meant a very large volume of certificates per system. Many installers who started in that period remember it as a time when the rate you were quoted in the morning might not be the rate you were paid.
We will not give a chart of those years here, because we cannot verify one in this article. The CER’s Quarterly Carbon Market Report is the authoritative source.
Phase two: settling under the ceiling
As the scheme matured, three things steadied the market:
- The Small-scale Technology Percentage. The CER sets an annual percentage for liable entities, based on expected generation, which gives demand a published anchor.
- Shorter deeming. The deeming period shrinks each year, so each system creates fewer certificates and the supply per install falls.
- A known ceiling. With $40 as a hard limit, price risk is capped on one side.
Through the 2020s the market has typically traded in the high $30s, with brief dips when supply was heavy or demand was thin. At the time of writing the spot market has been roughly $38 to $40.
Phase three: batteries change the supply picture
From 1 July 2025 the Cheaper Home Batteries Program began issuing STCs for batteries as well as solar. That added a new source of certificates, and traders had to plan for the volume. For 2026 installs the factor is 6.8 STCs per kWh of usable capacity, stepping down to 5.7 on 1 January 2027 and 5.2 on 1 July 2027 (the factor now steps every six months to 2030).
So far the price has held near the top of its range. That does not mean it must. A big supply shock or a change to targets could move it. Our battery STC pages cover the mechanics of the program itself.
What the pattern tells you
| Period | Pattern | Lesson for installers |
|---|---|---|
| Early scheme | Wide swings | Never quote on yesterday’s rate without a lock |
| Mature scheme | Narrow band under $40 | Rate differences between traders matter more than market moves |
| Battery era | Higher volume, so far stable | Watch supply, but do not assume a fall |
The second row is the one most installers live in. In a market that moves by a dollar or two, the difference between a trader paying you $38.50 and one paying $37.20 on a 45-STC job is $58. Over 40 jobs a month, that is $2,340. Meanwhile the market itself may not move by that much in a quarter.
Why a rate lock matters more than a forecast
If the price barely moves, the risk is not that the market moves against you after you sell. The risk is the gap between the rate you saw and the rate you got. A trader that fixes the rate when you lodge a complete claim removes that gap. Ask every trader exactly when the rate becomes fixed. Our certificate trader checklist lists the other questions.
From the desk: Keep your own log of the rate you were offered and the rate you were paid, job by job, for three months. Most installers have never compared the two. If the paid rate is regularly below the offered rate, you have found a hidden fee, and it costs you more than any market dip.
Reading the next move
History does not forecast, but it does show what moves the price: supply surges, changes to the percentage, policy changes to the scheme, and shifts in how fast traders can get certificates through the registry. We set out the factors, and three honest scenarios, in STC price forecast. For the pricing mechanics, see STC pricing explained.
Why long-run charts can mislead
A line chart of the STC price is tempting, but it hides the thing that matters on a given job: what you were actually paid. Traders quote a headline rate, then subtract fees, apply delays, or reset the rate on settlement. Two installers selling the same 45 certificates on the same day can bank different amounts. Price history tells you the market’s range. Your own remittance records tell you your real price. Use the first to sanity-check offers, and the second to judge whether the trader behind them is delivering.
It also helps to separate three numbers that people use interchangeably: the clearing house price ($40), the spot market price (just under it), and the rate card price you are offered. The gap between the last two is where trader margin, risk and service live, and it is the only gap you can negotiate.
What to do next
- Check today’s published rate on the pricing page and note it with the date
- Start the rate log described above, using your last 20 jobs
- Read what changes in January 2027 before you quote jobs for next year
- If you want a rate locked on lodgement, see how STC trading works