Grid guide
Western Power essentials for home batteries
The three grid rules that shape your battery system: how big your inverter can be, how much you can export, and emergency limits.
Key numbers
- Total inverter capacity
- 30kVA
- From 1 May 2026, battery inverters included
- Starting export, no retailer offtake
- ~1.5kW
- Many sites start here
- ESM applies to systems new or upgraded from
- 14 Feb 2022
- Emergency export limits
Inverter capacity and generation limits
From 1 May 2026, homes on Western Power's network can install up to 30 kVA of inverters in total, including battery inverters. On a single-phase connection the system can be larger than 15 kVA but must be set so it never produces more than 15 kVA at once (10 kVA in some rural and small-network areas). Your installer must get Western Power approval before connecting and will confirm the exact limits for your property.
| Limit | Most areas | What it means |
|---|---|---|
| Total inverter capacity | 30 kVA | All inverters added together, solar and battery, single- or three-phase |
| Single-phase generation | 15 kVA | The most the system may produce at once. A bigger system is set to stay under it.10 kVA in some rural and small-network areas |
| Three-phase generation | 8 kVA per phase | The most each phase may produce at once5 kVA per phase in some rural and small-network areas |
Source: WEM Procedure: Technical Requirements for Standard Small User Facilities.
Export limits and DOEs
Without a retailer offtake
Many sites start with about 1.5 kW export.
With offtake or DOEs
With offtake or Dynamic Operating Envelopes, exports can vary with network conditions.
Your installer will confirm the approved limit on your connection. Export limits explained
Emergency Solar Management (ESM)
For new or upgraded systems from 14 Feb 2022, WA can temporarily limit exports in rare emergencies to protect grid stability. This covers solar and batteries.
Commissioning note
Terms on this page
- kVA
- A measure of power: how much an inverter can put out at once.
- Generation limit
- The most your system may produce at once. Your installer sets it in the inverter.
- Retailer offtake
- An agreement with your retailer to take (and pay for) the power you export.
- DOE
- Dynamic Operating Envelope. An export limit that changes with how busy the local network is.
- SWIS
- The South West Interconnected System: the main WA grid, run by Western Power.
- Region B
- The WA setting in the inverter standard AS/NZS 4777.2. Your installer sets it.