If you build or maintain commercial solar, there is a point where the certificate you claim changes. Up to 100 kW, the system creates STCs upfront and you sell them within days. From 1 October 2026 the same is true up to 1 MW, with a fixed five-year deeming period (see mid-scale solar STCs). Above 1 MW, or for older systems above 100 kW installed before that date, the system is a power station in the eyes of the Clean Energy Regulator (CER), and it earns Large-scale Generation Certificates, one for every megawatt-hour it actually generates.
That is a different business. Certificates arrive slowly, there is no fixed clearing house price, and the buyer is usually a retailer or trader negotiating a contract. This article walks through how LGC trading works from accreditation to settlement, so you can quote commercial jobs with the certificate value understood rather than guessed.
What an LGC is, and who needs one
An LGC is one MWh of eligible renewable generation above the station’s baseline. They exist because of the Large-scale Renewable Energy Target, which obliges electricity retailers and some large users to surrender LGCs each year. Demand for LGCs is regulatory demand, and the price follows how many certificates are in the market against how many are needed.
For a solar installer, the practical rule depends on size and install date:
| System | Certificate | When you get it |
|---|---|---|
| Up to 100 kW (and within SRES rules) | STCs | Upfront, deemed over the deeming period |
| Over 100 kW to 1 MW, installed from 1 October 2026 | STCs | Upfront, fixed five-year deeming period |
| Over 1 MW, or over 100 kW installed before 1 October 2026 | LGCs | As the system generates, year by year |
For the STC side, see our guide on what an STC is worth in 2026. For the old dividing line in more detail, the answers on commercial solar over 100 kW and LGCs and LGC versus STC cover the edge cases.
The path from switch-on to first sale
LGCs do not appear on commissioning day. The sequence looks like this:
- Accredit the power station. The owner (not usually the installer) applies to the CER with technical details, the connection agreement and evidence of the system’s capacity and metering.
- Register a baseline. Most new solar stations have a zero baseline, so every MWh generated counts.
- Report generation. The owner submits electricity generation data to the CER, typically annually or more often, backed by revenue-grade metering.
- Create certificates. After the CER validates the data, LGCs are created in the registry and appear in the owner’s account.
- Transfer and settle. Certificates are transferred to a buyer under a contract, and payment follows the agreed terms.
Each step has a cost in time. Many owners find that the money is not worth the effort on a small commercial system unless someone handles it for them. That is the opening for installers: a clean, repeatable offer to manage accreditation and creation, or to refer it to a specialist.
A worked example
A 150 kW rooftop system installed before 1 October 2026 in a sunny zone might generate somewhere around 200 MWh in a year, after losses. LGC spot has been roughly $6 to $9 in September 2026.
- 200 LGCs at $7.50 is $1,500 for the year
- Over ten years, with some degradation, around $13,500 to $14,000 at that price, before any admin cost
That is real money, but it is small next to the system price and the avoided power bills, and the number moves with the market. Compare it with an upfront STC claim: a 150 kW system installed from 1 October 2026 would create 150 x 1.382 x 5 = 1,036 STCs (zone 3), claimed in the first weeks. Our answer on how much an LGC is worth shows the arithmetic for other system sizes.
Before 1 October 2026 this is why some commercial clients preferred to size to 99 kW, and it is why the CER watched for systems split to stay under the limit. With mid-scale STCs in place there is no reason to split a site that really is one 150 kW installation. It is a compliance risk, and our STC audit guide explains how those reviews begin.
How LGCs are priced and sold
There is no clearing house for LGCs. Price discovery runs through brokers, retailers and trading desks, with a published spot price and forward prices for future delivery.
You will usually see three routes:
- Spot sale. You sell what is in your account at the going price. Simple, but you take whatever the market gives that week.
- Forward contract. You agree a price now for certificates to be delivered over a period. This fixes revenue, which matters if the client has financed the system.
- Power purchase agreement bundle. The offtaker buys the electricity and the certificates together. Check who owns the LGCs in the PPA before you assume the host does.
Whichever route you take, read the contract for who pays brokerage, when payment is made after transfer, and what happens if the registry transfer fails. Our certificate trader checklist applies here with only small edits.
From the desk: Settle ownership on day one. On commercial jobs the owner, the host and the financier can all be different parties, and each assumes the LGCs belong to them. Put the certificate owner’s name in the proposal, the accreditation application and the sale contract. Disputes over who holds the certificates are far more expensive than the certificates.
What moves the price
Four things matter, and you do not need a model to track them.
Surrender demand. The annual target is fixed by legislation. Liable entities buy what they need to cover their liability.
New supply. Large wind and solar farms coming online add certificates. When supply runs ahead of the target, prices fall, which is part of the story in our piece on LGC oversupply to 2030.
Time left in the scheme. The scheme runs to 2030, so a certificate created late has fewer years of demand behind it, and forward curves reflect that.
Policy. Changes to how the government supports renewables after 2030 can shift expectations. Check the CER and the relevant department for current settings before you promise a client any long-run number.
What installers actually do with this
Most small crews will not trade LGCs themselves. The useful thing is knowing enough to set the client’s expectations:
- Tell the client at quote stage which certificates their system will create and when.
- Show the LGC revenue as a range, not a number.
- Offer a path (an accredited partner or broker) for registration and sales.
- Keep the generation metering and commissioning evidence tidy, because that is what the CER will ask for.
If your volume is in STCs, the practical alternative is to keep your commercial work inside the SRES, which now reaches 1 MW, and where you cannot, pass the LGC admin to a specialist. The STC trading page explains the upfront side, and the resources hub lists the checklists for evidence.
What to do next
- Check each commercial enquiry’s size and install date (100 kW and 1 MW, and 1 October 2026) before you quote certificates.
- Decide whether you will manage LGC accreditation or refer it, and write the answer into your proposal template.
- Get ownership of the certificates in writing at the start of every job.
- For the STC side of your book, see today’s published rates on the pricing page, and read how it works if you are new to selling certificates.