Batteries and STC prices are linked because battery certificates are STCs. They go into the same market, to the same buyers, against the same $40 ceiling.
What the program does
From 1 July 2025 eligible batteries between 5 and 100 kWh usable, with up to 50 kWh counted, create STCs for the installer to assign. The factor, the certificates per kWh, steps down: 9.3 for July to December 2025, 8.4 for January to April 2026, 6.8 for May to December 2026 (at the time of writing), then 5.7 on 1 January 2027 and 5.2 on 1 July 2027, continuing down to 2030. Since 1 May 2026 the first 14 kWh counts at 100% of the factor, 14 to 28 kWh at 60% and 28 to 50 kWh at 15%. See battery STCs.
Why it matters for price
A battery of 10 kWh at a factor of 6.8 creates around 68 certificates, comparable to a mid-sized solar system. At high uptake, the program creates a large number of extra STCs in a market whose demand, the liable entities’ obligation, was set with solar and heat pumps in mind. The program budget was expanded from $2.3 billion to $7.2 billion, as reported, which signals expectations of continued uptake.
What oversupply looks like
- Spot drifts below the ceiling. At the time of writing it has been roughly $38 to $40.
- The Clearing House queue grows. Certificates sit unsold at $40 while buyers wait. This is the “surplus in the queue” that market updates describe in 2026.
- Traders widen margins or slow payment. They bear the price risk of holding certificates.
What limits it
The declining factor schedule means each battery creates fewer certificates each half-year. The tiered cap on large batteries trims volume above 14 kWh. And the 2030 end date caps the horizon. See how the battery factor falls.
What this means for installers
Price effects from batteries are measured in cents, not dollars, but on a 68-certificate battery cents add up. Quote from a locked rate, send claims with complete photos, and watch settlement time. Our pricing page shows the daily rate for battery certificates, and the battery submission guide lists what a clean claim needs. See also the Cheaper Home Batteries installer guide and STC price below $40.