STCs, LGCs and REGOs: which certificates your business solar creates

A certificate is a tradable record that a quantity of renewable energy has been generated, or is expected to be. Selling the certificates is how a solar project gets paid by the federal scheme. Which type you create depends on your system’s size and install date, so it is worth knowing before you compare quotes.

What are STCs, LGCs and REGOs?

The Clean Energy Regulator (CER) describes LGCs as tradable certificates created for eligible large-scale renewable power stations, with each LGC equal to one megawatt-hour of renewable electricity. They are created by the nominated person of an accredited power station. The large-scale and small-scale schemes run side by side until the Renewable Energy Target ends in 2030, and accredited power stations can join the REGO to continue creating certificates beyond 2030.

STCs work differently. Instead of waiting for each megawatt-hour, the system is credited up front with its expected output over a set number of years, called the deeming period. That is why an STC shows up as a discount on the price.

Which certificate does my system earn? Size and date

The date that counts is when the system is first capable of producing and delivering electricity. For mid-scale systems, that is the testing and commissioning date on the certificate of electrical compliance (or the state or territory equivalent). Our guide to mid-scale STCs from 1 October 2026 covers the evidence and the transition in detail.

Can a system earn more than one type?

Not for the same capacity. The CER is clear on two points:

• STCs and LGCs: a solar system cannot create both for the same generation capacity. Support for eligible new mid-scale solar comes through the small-scale scheme rather than the large-scale one.
• STCs and REGOs: if you choose STCs for a mid-scale system, you cannot create REGO certificates for the deeming period.

What are STCs worth for a business?

The CER says it does not set the price agents pay, and that agents usually pay $33–$38 per STC. Through the STC clearing house, pricing is capped at $40 excluding GST, and open-market prices change daily. Multiply your certificate count by a price in that range to estimate the discount.

Worked example: a 200 kW system (an estimate only)

Assume 200 kW in zone 3 (rating 1.382), installed after 1 October 2026 with a 5-year deeming period, and $35 a certificate. That is 200 × 1.382 × 5 = 1,382 certificates, or about $48,400. We have not found a published formula for mid-scale systems, so treat this as an estimate and confirm it with the CER’s mid-scale STC calculator. Use our STC calculator for smaller systems.

Do batteries earn certificates too?

Yes, eligible batteries earn STCs, which are the basis of the battery discount. For 2026 the factor is 8.4 per kWh from January to April and 6.8 from May to December, with the factor tapering by battery size. Read how business batteries are discounted and, in NSW, the NSW business battery discount.

What should you do before you sign?

• Ask which certificate the quote assumes, and in what year it expects the system to be commissioned.
• Check the discount is a separate line, with the number of certificates and the price per certificate.
• If you have any solar already on site, ask how it affects eligibility and metering.
• If you want REGOs, ask your accountant and installer before committing to STCs, because the choice affects the deeming period.

For the bigger picture, see commercial solar rebates and incentives and how much commercial solar costs.

This guide is general information, not financial or legal advice. Rules, rebates and prices change, so check the linked sources before you decide. Facts checked 31 October 2026.