Gold Coast Solar Rebate Calculator

Solar Rebate Calculator

Why can’t I have a system larger than 100kW?

Systems over 100kW aren't eligible for STCs. They fall under a different scheme (LGCs).

Why is the default 6.6kW?

6.6kW is the most common system size for Australian households.

Why this matters

The rebate reduces each year until it reaches zero in 2031. The install year determines how many STCs you get.

1. User Inputs

The calculator requires the user to enter two values:

  • System size (in kilowatts) — e.g., 6.6 kW

  • Installation year — e.g., 2025

2. Constants Used in the Calculation

These values are fixed within the calculator:

  • STC price: $36.00 — average value in the Australian market (can fluctuate)

  • Zone multiplier: 1.382 — fixed for Gold Coast, based on its solar radiation (same as Zone 3)

  • Sunlight hours (for reference): approximately 1,930 hours per year

  • Deeming period: calculated based on the year selected

3. Deeming Period Logic

  • The Small-scale Renewable Energy Scheme (SRES) rebate reduces over time.

  • The deeming period is:

     
    Deeming Period = 2030 - Installation Year

    Example:

    • For installation in 2025: 2030 - 2025 = 5 years

    • For installation in 2029: 2030 - 2029 = 1 year

    • For installation in 2030 or later: 0 years (no rebate)

4. STC Calculation Formula

The number of Small-scale Technology Certificates (STCs) is calculated as:

STCs = System Size (kW) × Zone Multiplier × Deeming Period

Example:

  • System Size = 6.6 kW

  • Zone Multiplier = 1.536

  • Deeming Period = 5 (for 2025)

  • Result: 6.6 × 1.536 × 5 = 50.6 STCs

5. Rebate Calculation Formula

Once the number of STCs is calculated, the total rebate is:

Rebate = STCs × STC Price

Example:

  • STCs = 50.6

  • STC Price = $37

  • Rebate: 50.6 × 37 = $1,872.20

6. Constraints

  • The system size must be 100 kW or less (above this, the system is not eligible for STCs).

  • The rebate becomes zero once the year reaches 2031, as the deeming period will be 0.

Summary of Calculation Flow

  1. User enters system size and install year.

  2. Calculator checks for size limit and computes the deeming period.

  3. It multiplies: System Size × Multiplier × Deeming Period = STCs.

  4. Then it multiplies: STCs × STC Price = Rebate.

  5. The result is shown to the user, along with the STCs and assumed sun hours.