For an installer the two certificates are very different cash events.
STCs: upfront
When you install a small-scale system, the number of STCs is calculated at installation using system size, zone rating and deeming period. The certificates are created through the REC Registry and sold. With a fast trader, the money arrives within days. Energy Merchants settles in 24 hours for established partners, with a first claim at 48 to 72 hours. That fits the way installers fund a job: buy equipment, install, claim, pay the distributor.
LGCs: over time
LGCs are created after generation. A 200 kW system makes roughly 260 to 300 LGCs a year, worth about $1,600 to $2,700 a year at roughly $6 to $9 per LGC (September 2026), and they normally belong to the system owner. They will not fund your next job. See the LGC vs STC difference.
What changed on 1 October 2026
Systems above 100 kW and up to 1 MW installed from 1 October 2026 can create STCs with a fixed five-year deeming period. In zone 3, a 250 kW system gives 250 x 1.382 x 5 = about 1,728 STCs, or roughly $65,700 to $69,100 at $38 to $40 each at the time of writing. That is a far bigger upfront discount than LGCs ever offered and helps customers say yes. CER applications are reported to open mid to late November 2026. See mid-scale solar STCs and solar systems just over 100 kW.
Cash cycle comparison
| Feature | STCs | LGCs |
|---|---|---|
| When created | Upfront at install | After generation |
| Who typically holds them | Owner, assigned to installer or trader | System owner |
| Installer cash timing | Days | Not relevant to your cash |
| Price risk | Spot roughly $38 to $40, clearing house cap $40 | Volatile, roughly $6 to $9 |
Protecting cash on a large job
Agree with the customer who is assigning the STCs, confirm the amount before quoting and check how your trader handles a big claim. See installer cash flow and STCs and payment within 24 hours.
A note on contracts
Check who is named on the assignment form or certificate agreement, and whether the customer expects a certificate discount on the invoice. On large jobs, put the STC amount and the basis of calculation in the quote, and state that the final number depends on the CER accepting the claim. That protects you if processing takes longer than expected.
What this means for installers
Treat mid-scale solar as a new product line. Learn the rules, ask your trader how it will handle claims and show customers the discount in the quote. See pricing, how it works, start trading and the commercial solar hub.