NSW pays tradeable certificates (PRCs) on new battery storage for apartment buildings, business sites and large C&I — on top of the federal STC rebate you already quote. Tell it the site type and the system size and it works out which activity fits; the statement shows the certificate count, the full working and the eligibility checklist, straight from the PDRS (Amendment No. 2) Rule 2026. Print it, staple it to the quote.
| BESS3 — Apartments | BESS4 — Business | BESS5 — Large C&I | |
|---|---|---|---|
| Site | BCA Class 2, ≥ 4 dwellings | Non-residential, not a data centre | Non-residential, not a data centre |
| Usable capacity | 20 – 200 kWh | 20 – 200 kWh | 200 – 30,000 kWh |
| Capacity caps | 5 kWh per dwelling · 4 × inverter kW | 4 × inverter kW | 10,000 kWh · 4 × inverter kW |
| Rate with new solar | 0.12 | 0.10 (marginal to 100 kWh) | 0.10 |
| Rate without | 0.0853 | 0.067 (marginal to 100 kWh) | 0.067 |
| How often | First battery at the NMI | Once per site, shared with BESS5 | Once per site, shared with BESS4 |
| Notable equipment rules | 10-yr warranty ≥ 70% · outdoor install | 10-yr warranty ≥ 70% · solar ≥ ¼ capacity | UL9540A tested · solar ≥ ¼ capacity |
Yes — the Rule allows an eligible battery to claim both PRCs and federal Small-scale Technology Certificates on the same install, where the battery also meets the federal program's own eligibility: 5–100 kWh nominal capacity, installed with new or existing solar, with STCs paid on the first 50 kWh of usable capacity at the factors current on the install date. Above 100 kWh nominal there is no federal stacking — the estimate here is PRCs only. Quote the STC side in the Deye Designer; it shows the STC figure for eligible systems.
No. The battery must be internet-connectable and capable of being controlled by a Demand Response Aggregator — a hardware capability, not a signed VPP contract.
The battery activity definitions apply to installations with an implementation date on or after 1 September 2026.
BESS4 and BESS5 share a once-per-site limit — one battery activity between them. BESS3 requires that no battery already exists at the same NMI.
One source, and it is the Rule itself. Every equation on this page is implemented from the Peak Demand Reduction Scheme (Amendment No. 2) Rule 2026 — clause 6 (certificate equation and rounding), clause 8.1 (the 6-hour peak window over a 15-year lifetime), clause 10.1 (usable capacity is 90% of nameplate), Schedule A Table A3 (network loss factors) and Schedule C (the BESS3, BESS4 and BESS5 activity definitions). The scheme is administered by IPART, who publish the Rule and every amendment to it. No supplier interpretation, marketing deck or competitor calculator was used as a maths source.
Checked against someone who does this for a living. An Accredited Certificate Provider operating in the scheme publishes worked certificate figures in its own partner guidance. Every one of those figures reproduces exactly here — across apartment buildings, business sites either side of the 100 kWh threshold, with and without new solar, and large C&I at the certificate cap. That agreement counts for something precisely because the two were worked out independently from the same Rule, so it is a check on our reading rather than a copy of theirs. It runs as an automated test on every change: if this tool ever drifts from those figures, the build fails.
What that does not mean. No ACP has reviewed or endorsed this tool, and nothing here is a certificate entitlement. IPART has not yet published the approved product list, so no product is confirmed eligible. The Rule also lists new solar of at least a quarter of usable capacity as an equipment requirement while still publishing without-solar equations — an ambiguity we flag rather than resolve. Your ACP is the authority on what will actually be created. Take the statement above to them.