Tesla Powerwall vs Sigenergy: which battery suits your home?
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Short answer: Powerwall 3 is one 13.5 kWh unit with its own solar inverter and backup gateway, and works with solar you already have [SB-S052, E]. Sigenergy is a stack of 8.76 kWh modules on its own inverter, so you choose the size, but backup costs extra [SB-S060, SB-S092, C]. On the dated prices we hold, Sigenergy costs less per kWh; the prices come from different installers, cities and months, so treat this as a guide, not a quote [SB-S061, SB-S092, SB-S060, E].
Side by side (as at 3 November 2026)
| Tesla Powerwall 3 | Sigenergy SigenStor | |
|---|---|---|
| Usable storage | 13.5 kWh per unit, up to 3 Expansion units [SB-S052, C] | 8.76 kWh per BAT 10.0 module [SB-S060, C] |
| Power | 5 / 10 / 11.04 kW AC continuous by setting [SB-S052, C] | 4.6 kW continuous per module [SB-S060, C] |
| Round-trip efficiency | 89% solar-to-battery-to-home [SB-S052, C] | MISSING (datasheet not readable by us; SB-S060 is a search extract) |
| Warranty | 10 yrs; 70% at 10 yrs; unlimited cycles for self-use, time-based and backup, else 37.8 MWh [SB-S053, C] | 10 yrs; 70% or 33.29 MWh per module, whichever first [SB-S059, C] |
| Installed price, seller's own date | $10,633–$12,633 after federal discount, single phase with solar, incl. Gateway 2 and backup, Canberra installer, as at September 2026 [SB-S061, C] | from $8,067.60 after federal discount, 18 kWh (about 2 modules), standard install, as at 3 November 2026 [SB-S092, C] |
| Price per usable kWh | about $788–$936 [SB-S061, E] | about $460 (2 modules, 17.52 kWh) [SB-S092, SB-S060, E]; backup not included |
| Backup | Backup Gateway 2, included in that price [SB-S052, SB-S061, C] | Gateway extra: partial backup +$1,455.90 single phase on that list [SB-S092, C] |
| CEC approved list | 1707000 Powerwall 3, 13.5 kWh, listed to 17 Oct 2027 [SB-S070, C] | Whole SigenStor systems only, not the single module; listed to 5 Jun 2027 [SB-S069, C] |
What the federal discount is worth at these sizes
Our arithmetic, not a quote: installs from May to December 2026 earn 6.8 STCs per usable kWh up to 14 kWh, then 60% of that to 28 kWh [SB-S036, SB-S001, C]. The factor drops to 5.7 for installs from January 2027 [SB-S036, C]. The discount is set by the installation date [SB-S004, C]. It needs a CEC-listed, VPP-capable battery installed with solar by an SAA battery-endorsed installer [SB-S003, C]. The STC price moves, so your installer's figure will differ. Official rules: cer.gov.au and dcceew.gov.au.
- Powerwall 3 (13.5 kWh): 91 STCs, about $3,608 with STCs at their last traded price of $39.65 (30 Oct 2026) [SB-S095, E].
- Sigenergy 2 modules (17.52 kWh): 109 STCs, about $4,322 [SB-S036, SB-S001, SB-S095, E].
Installers pass on a bit less than the trade price [SB-S095, C]. For what a Sigenergy battery costs at each size, see what a Sigenergy battery costs.
Full Powerwall detail: the Powerwall 3 specs and price.
Who each one suits
Powerwall 3 suits you if you already have solar and want one box that handles it, with backup in the price [SB-S052, SB-S061, C].
Powerwall 3 is not for you if you need less than 13.5 kWh, or you're price-first: it's the dearest per kWh of the dated prices we hold [SB-S061, SB-S092, SB-S060, E].
Sigenergy suits you if you want to size the battery to your evening use and add modules later [SB-S060, C].
Sigenergy is not for you if you have a good hybrid inverter you want to keep, because SigenStor brings its own [SB-S061, SB-S092, SB-S060, E], or you want blackout cover without an extra line item [SB-S092, C].
Honest downsides
- Powerwall 3: one size per unit, so you buy storage in 13.5 kWh steps [SB-S052, C].
- Sigenergy: the throughput cap (33.29 MWh per module) can end the warranty before 10 years on heavy daily cycling [SB-S059, C].
- Sigenergy: the CEC lists systems, not modules, so check the exact system name on your quote [SB-S069, C].
Other comparisons
If Sungrow is on your shortlist too, its SBR listing ends 30 Dec 2026 [SB-S071, C]; see the Sigenergy and Sungrow comparison and Tesla Powerwall or Sungrow. Lower-priced modular stacks are covered in the FoxESS and Sungrow comparison. Queensland has no state battery rebate open, so only the federal discount applies: what Queensland buyers get [SB-S044, C].
Ask your installer, in writing
- The exact model or system name as it appears on the CEC approved list, and its usable kWh [SB-S026, C].
- How many STCs the quote assumes, and for which install date [SB-S004, C].
- What stays on in a blackout, and the line-item cost of backup.
- Warranty years, the 70% figure and the throughput cap.
Rules checked 3 November 2026. Next scheduled check: before 1 January 2027 (STC step-down), and monthly for WA and NSW.