Under the Large-scale Renewable Energy Target, power stations can create large-scale generation certificates (LGC) for eligible renewable energy generated. Power stations can create one LGC for each megawatt hour (MWh) of electricity generated.

To be eligible to apply for the solar irradiance methodology, your power station must be solar and generate over 100 kilowatts (kW) but under one megawatt (MW). Our solar irradiance methodology automatically calculates LGC entitlements for participating solar power stations.

The methodology helps to:

  • remove manual data entry in the REC Registry for applicants
  • process LGC claims faster
  • limit our need to request extra claim information.

How it works

Our methodology is an automatic system that:

  • calculates the eligible electricity
  • credits the nominated persons' REC Registry account with LGCs.

We calculate LGCs from eligible electricity using our irradiance model and the solar power station's:

  • hardware specifications
  • location
  • solar panel azimuth (orientation) and tilt
  • site-specific, real-time, solar irradiance and air temperature data.

We account for shading and soiling of solar panels to calculate LGC entitlement. This increases the accuracy of the irradiance model for each solar power station.

We'll credit one LGC per MWh of eligible electricity to the solar power station. Nominated persons must pay the LGC creation fee in the REC Registry to access their LGC entitlement.


New solar power stations and existing accredited power stations can apply. If you're a new power station, include the SIM application form with your accreditation application. If already accredited, send us an application form to opt-in via ret-lgcvalidation@cer.gov.au.

You can apply to use the solar irradiance methodology if:

  • all generated electricity is from fixed (non-tracking) solar panels
  • capacity is greater than 100 kW and under one MW
  • all listed components are consistent with what's listed on the REC Registry
  • the power station is properly maintained and operates reliably.
Opt-in with our application form

We'll assess your application to ensure you're eligible to use the methodology.

If approved, we'll switch your power station to the methodology and let you know.

We need at least 3 months of meter data before switching your power station. This ensures there are no issues preventing operation in the methodology.

You will continue to operate under the methodology until you opt out of the date listed on the application. You can opt out after participating for 3 months. If you want to opt out, email us with the power station name and accreditation code at ret-lgcvalidation@cer.gov.au.

Methodology requirements

While using the methodology to calculate LGC entitlements, you must:

  • follow all compliance requirements for maintaining an accreditation
  • submit an annual electricity generation return, showing that it maintained compliance with its permit conditions
  • tell all stakeholders that you've opted in to use the methodology if the owner doesn't manage the system
  • report if there's a change to the system's capacity or ability to generate power.

You're not required to monitor the power station 24/7, report or notify us if there's an outage or damaged components that caused an impact to generation. We will inform if further action is required.

Changes to a system's ability to generate power include:

  • being switched off, disconnected or damaged
  • suffering from a fault or condition
  • having a minor outage (single-day outages, solar panels going offline or needing repairs)
  • having a significant outage (whole power station outage lasting 3 days or more).

Your responsibilities are the same as if you were submitting LGCs without the methodology.

Once LGC entitlement has been calculated using Solar Irradiance methodology, it cannot be varied unless there was a fault in the power station's generation.

We may stop operating the methodology for a power station at our discretion. If discontinued, your power station will revert to using a meter-based methodology for your power station.