LGC Certificates for Commercial Solar: 2026 Guide

In short: Large-scale Generation Certificates (LGCs) are the federal incentive for solar capacity above the STC ceiling: 1 MW of site capacity for installs from 1 October 2026 (100 kW before). Unlike the upfront STC discount on smaller systems, LGCs are earned annually: one certificate for every megawatt-hour the system actually generates, verified against meter data, until the scheme ends in 2030. Two things have changed the LGC conversation in 2026: certificate prices have fallen hard as large-scale supply outran the fixed federal target, and a registered STC expansion replaces LGCs entirely for new 100 kW–1 MW systems installed from 1 October 2026.

What Is an LGC?

A Large-scale Generation Certificate represents one megawatt-hour of renewable electricity generated by an accredited power station under the federal Large-scale Renewable Energy Target (LRET). The LRET obliges electricity retailers to surrender a set number of certificates each year, which creates the demand side of a traded certificate market. Your solar system supplies the other side: generate a megawatt-hour, create a certificate, sell it.

The word “large-scale” is doing less work than it sounds. For solar installed from 1 October 2026, the first 1 MW of a site’s capacity claims Small-scale Technology Certificates (STCs), which are deemed upfront rather than earned year by year, and only the balance above 1 MW earns LGCs. For installs before 1 October 2026 the line was 100 kW, which put a mid-sized warehouse roof in the same scheme as a grid-scale solar farm. Either way a system above the line is split: STCs up to the ceiling, LGCs on the balance.

Who Is Eligible, and What It Takes

To create LGCs on capacity above the STC ceiling, a system must be accredited as a power station with the Clean Energy Regulator. That brings obligations a small system never sees: an application before certificates can be created, revenue-grade metering of generation, and annual electricity generation returns. Certificates are created in the regulator’s registry against actual metered output, then sold either through a broker or agent, under a long-term offtake, or on the spot market.

This was the administrative trade at the heart of the old 100 kW line. An STC system gets its incentive as a point-of-sale discount and never thinks about it again. An LGC system takes on registration and reporting in exchange for a revenue stream that arrives one year at a time. That overhead, more than the certificate maths, is why so many Australian commercial roofs carry a 99 kW system.

LGC vs STC at a Glance

For the full three-scheme comparison including Victorian VEECs, see STC vs VEEC vs LGC. The short version for stacking: a 100–200 kW Victorian system can pair its LGCs with VEECs, and any state can pair LGCs on the solar with battery incentives on a co-located battery.

What an LGC Is Worth in 2026

Here is where most older guides will mislead you. LGC spot prices spent years in the $40s and $50s, and a lot of published content still quotes those numbers. The market has moved: the LRET target has been fixed at 33,000 GWh since 2020 while large-scale wind and solar kept building, so certificate supply now comfortably exceeds the demand retailers are obliged to meet. Spot prices slid through 2025 (around the low $30s in January) and by mid-2026 were trading well below that, with forward prices declining further toward the scheme’s 2030 end date. Amperage’s calculators seed their LGC price from an admin-managed default that is reviewed against the market; treat any single number, including the ones on this site, as a snapshot.

That does not make LGCs worthless: on a 250 kW system generating around 350 MWh a year, they are still real revenue, and voluntary demand (corporates surrendering certificates for green claims) puts a floor under the market that the mandatory target no longer provides. But it does change how they should be quoted. An LGC stream priced at a flat $45 per certificate for ten years overstates the asset badly; priced off the current forward curve it is a modest, declining line item that ends in 2030. If a payback figure you have been shown leans heavily on LGC revenue, ask which price and which years sit behind it. The LGC calculator uses a live market default you can override to match your broker’s pricing.

The October 2026 Change: STCs to 1 MW

The second thing reshaping the LGC story: STC eligibility now extends from 100 kW up to 1 MW for solar installed from 1 October 2026. The change was announced on 5 August 2026, and the Mid-scale Solar Regulations were registered on 17 September 2026 and are in force. A new 300 kW system takes a whole-system upfront STC discount at a fixed five-year deeming instead of registering as a power station and collecting LGCs against a weakening price outlook. Given where LGC prices sit, that trade favours the upfront certificate for almost any new mid-scale project.

Three caveats. The change only reaches systems installed on or after 1 October 2026, so the 100 kW limit still governs anything commissioned before then. Systems already accredited for LGCs keep their arrangements, and their capacity counts towards the 1 MW test for new solar on the same or an adjoining site. And a site totalling more than 1 MW earns STCs on the first 1 MW and LGCs on the balance. We covered the change in detail in the STC expansion guide.

How Amperage Models LGC Revenue

Because LGCs are annual, market-priced, and time-limited, modelling them as a flat number is the easiest way to flatter a payback figure. Amperage prices the stream the way the market does: the certificate count rides the system’s actual modelled generation (degrading a little each year as panels age), each year is valued against a per-year forward LGC price rather than a single flat rate, and the stream stops at the end of 2030 when the LRET ends. The same treatment runs through the sizing matrix, so when you compare a 99 kW scenario against a 150 kW scenario side by side, the LGC line reflects what those certificates are actually likely to fetch, not a 2023 price. For installs dated on or after 1 October 2026, the mid-scale STC regime is priced by default (switchable per project), with LGCs only on any capacity above 1 MW.

Every scheme, current price, and stacking rule lives on the solar incentives hub, which stays updated as the rules move.

The Short Version

LGCs pay commercial solar one certificate per metered megawatt-hour on capacity above the STC ceiling, every year until the LRET ends in 2030. They demand power-station accreditation and carry market price risk, and that market has fallen a long way from the $40s as supply outran the fixed target. For new 100 kW–1 MW installs from 1 October 2026, upfront STCs are the path. LGCs are for pre-October installs above 100 kW and for capacity above 1 MW, and those should be quoted off the forward curve, not off a blog post from three years ago.

LGC calculator – annual certificates and revenue for your system →

Solar incentives hub – every Australian scheme with live prices →