Calculating VEECs and ESCs
Calculating VEECs and ESCs with Bs & Be values.
VEECs
- Search the VEU Registry for your product (filter: 1D(18) & 3C - Water heater - Heat pump).
- Export the product data.
- Copy the Bs/Be values into the TRNSYS Tool (Res_Results or Com_Results sheet).
- Scroll right to view calculated VEECs.
ESCs
- Search the IPART Registry for your product (filter: Method = HEER).
- Export the product data.
- Copy the Bs/Be values into the TRNSYS Tool (Res_Results or Com_Results sheet).
- Scroll right to view calculated ESCs.
How the certificate values are calculated
The registry steps above describe the legacy TRNSYS Tool workflow, where Bs and Be are copied in and the spreadsheet returns the certificate counts. The underlying formulas are below so the logic is documented independently of any tool. Bs and Be are the boost energy outputs of the annual simulation. The .out values are already in GJ/year, not kJ.
STC (SRES)
STC is taken directly from the AS/NZS 4234:2008 simulation .out STC column. The certificate quantity is ROUNDDOWN(ROUND(STC_out, 1)), applied only when MDT ≥ 45°C and energy savings ≥ 60%. Do not derive STC from Bref. The 2008 .out value is the authoritative figure.
VEEC (VEU)
VEEC 1D, from VEU Specifications 2018 v23.0, Equation 1.2 (p20):
VEEC = (Abatement − SEF × Bs − AEF × Be) × EEF, with AEF = SEF.
VEEC 3C, Equation 3.1 (p23–24):
VEEC = (Abatement − ((SEF × Bs) + (AEF × Be))) × EEFm
The 3C structure differs from 1D, so do not reuse the 1D arrangement. EEF = EEFm = 0.393 (from 1 February 2025). The VEEC count is the greenhouse gas reduction, floored.
ESC (ESS)
ESC D17 and D19, from the ESS Rule 2025, Equation 1 (p10):
ESCs = ROUNDDOWN(ElecSavings × ECCF + GasSavings × GCCF)
where ElecSavings = BaselineA − a × (Bs + Be), and for D19 GasSavings = BaselineB. ECCF = 1.06, GCCF = 0.47, Life = 12.
Before lodgement
These factors and baselines change between specification versions. Spot-check the VEEC and ESC quantities against a known-good result before first lodgement, and update the factors when a new specification issues. STC is the most stable because it reads straight from the 2008 .out.