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If you are getting solar or a battery installed in Perth after 1 May 2026, you need to know about the new connection rules. Western Australia is updating how solar and battery systems connect to the grid on the South West Interconnected System (SWIS), which covers Perth and most of populated WA.
The changes were originally planned for February but were pushed to May to give the industry more preparation time. If your system is already installed, you can stop reading. These rules only apply to new installs and upgrades from 1 May onwards.
For everyone else, the short version is this: you now have to choose between two export pathways when your system is commissioned. One gives you full access to feed-in tariffs and future VPP programs but requires your inverter to accept remote management during rare grid emergencies. The other caps your exports at 1.5 kW with no strings attached. Which one makes sense depends on your setup.
Why WA needs different rules to the east coast
This is worth understanding because it explains why WA has rules that other states do not.
The SWIS is the world's largest isolated electricity grid. Unlike the National Electricity Market that connects NSW, Victoria, Queensland, South Australia and Tasmania, WA's grid stands completely alone. There is no interconnector to lean on if things get unstable. No neighbouring state to import from. It is an island grid, and it has to balance itself.
Think of it like a water tank with a fixed capacity. On the east coast, if one tank overflows, water moves to connected tanks. In WA, if the grid gets too much solar at midday and not enough demand to absorb it, there is nowhere for it to go. The Australian Energy Market Operator (AEMO) has to actively manage this balance in real time, and rooftop solar is now a major factor in that equation.
Perth has some of the highest rooftop solar penetration in the world. On a mild, sunny day when people are at work and air conditioners are off, the grid can genuinely struggle with the volume of solar being exported. The new rules are about giving the system operator a safety valve for those rare moments, while also opening up new possibilities like VPPs and flexible exports for everyone else.
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The two export pathways: pick your lane
From 1 May, every new solar or battery system on the SWIS must be commissioned under one of two export arrangements. Your electricity retailer (Synergy for most Perth customers) nominates the technical solution, and your installer configures the system accordingly.
Future-ready export
Full access to DEBS, VPPs, and flexible exports. Requires communications-capable equipment.
- check_circleFull DEBS access (10c/kWh peak, 2c/kWh off-peak)
- check_circleVPP participation when products become available
- check_circleFlexible export limits (higher when the grid allows)
- check_circleFuture-proofed for emerging grid services
- infoRequires Wi-Fi at inverter location
- infoEmergency Solar Management applies (rare, last resort only)
Standard export (1.5 kW cap)
Simple, no communications needed. But export earnings are severely limited.
- check_circleNo internet or Wi-Fi needed at inverter
- check_circleNo remote management of your system
- check_circleSimpler commissioning process
- cancelExport capped at 1.5 kW (anything above is curtailed)
- cancelNo DEBS feed-in payments
- cancelNo VPP eligibility
For the vast majority of Perth homeowners, the future-ready pathway is the obvious choice. The “cost” of accepting Emergency Solar Management is minuscule. South Australia has had an identical system since 2020, and it has been activated exactly once, for about one hour, costing affected households roughly $1 to $2 each.
The 1.5 kW standard pathway really only makes sense for a few specific situations: sheds or outbuildings with no internet, backup-only battery setups where you never intend to export, or properties where running Wi-Fi to the inverter location is genuinely impractical. For a typical Perth house with a router inside, the future-ready option is the no-brainer.
Emergency Solar Management: sounds scary, isn't scary
This is the part that makes people nervous. “The government can turn off my solar?” It is understandable why that triggers alarm bells. But the reality is much more boring than the headline suggests.
Emergency Solar Management (ESM) is a last-resort mechanism. Before any household solar is touched, AEMO and Western Power must first exhaust every other option: reducing output from large-scale generators, securing energy services, adjusting network configuration, and managing commercial solar systems. Only after all of that has been tried do they direct Synergy to reduce (not turn off) household solar exports.
Two critical points that get lost in the conversation:
Your household power stays on. ESM only reduces what you export to the grid. Your lights, appliances, and everything running off solar inside the house is unaffected. If you have a battery, it continues to charge and discharge normally.
It barely ever happens. South Australia has had this exact system running since 2020. In six years, it has been activated once, for about an hour. WA expects similarly rare use. The cost to households during that one SA event was estimated at $1 to $2 each.
If you are worried about ESM, think of it this way. You already accept that your electricity retailer controls your meter, your tariff rates, and your supply connection. ESM adds the ability for them to briefly reduce your export during a grid emergency that might happen once in several years. In exchange, you get full access to DEBS, VPPs, and flexible exports. It is not a difficult trade-off.
The technical bits (your installer handles most of this)
You do not need to memorise these standards, but it is useful to know what your installer should be doing. If they are not aware of the May 2026 requirements, that is a red flag.
| Requirement | Details |
|---|---|
| Inverter standard | AS/NZS 4777.2:2020, commissioned with “Australia Region B” settings |
| Communications protocol | CSIP-AUS (Common Smart Inverter Profile, Australia). Open-source standard for interoperability. Synergy customers must use this for the future-ready pathway. |
| Max inverter capacity | 30 kVA under standard connection (single-phase and three-phase). Covers virtually all residential systems. |
| Internet requirement | Wi-Fi must be accessible at the inverter location for the future-ready pathway. If connectivity drops, the system defaults to a lower static export limit until connection is restored. |
| Legacy equipment | Mixed brands, multiple inverters, or older hardware may require a gateway device to meet the CSIP-AUS standard. Discuss with your installer. |
| Who is responsible | Your electricity retailer (Synergy or Horizon Power) nominates the technical solution. Your installer implements it. Western Power enforces connection compliance. |
The good news is that most modern inverters from the major brands already support CSIP-AUS and the required Region B settings. If you are buying a Fronius, Huawei, Sungrow, or GoodWe inverter, your installer should be able to configure it to meet the new requirements without any additional hardware.
Where it gets more complex is with older or mixed-brand setups. If you are adding a battery to an existing system with an older inverter, you may need a gateway device to bridge the communications gap. Your installer should flag this during the quoting process.
The 30 kVA standard connection is the quiet win
Buried in the headline changes is a genuinely positive development that deserves more attention. From 1 May, systems up to 30 kVA of total inverter capacity can be installed under a standard connection application with Western Power.
This covers virtually every residential installation imaginable. A 30 kVA three-phase system is enormous for a house. Previously, larger residential systems sometimes required more complex application processes with longer approval times. The new threshold simplifies this for installers and customers alike.
For context, a typical 6.6 kW system uses a 5 kW inverter. A large 13 kW system uses a 10 kW inverter. Even a big 20 kW system with a 15 kW inverter and a 5 kW battery inverter is still well under 30 kVA. You would need a very unusual residential setup to exceed this limit.
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Who is affected and who can relax
check_circleNot affected
Any solar or battery system installed and commissioned before 1 May 2026. Your existing DEBS enrolment, export arrangements, and system configuration stay exactly as they are. No action required.
warningAffected: new installations from 1 May
If you are getting a brand new solar or battery system installed after 1 May, the new rules apply in full. You will choose an export pathway during the commissioning process. Make sure your installer is SAA-accredited and familiar with the updated Western Power technical requirements.
warningAffected: upgrades from 1 May
Adding a battery to existing solar, replacing an inverter, or increasing system size after 1 May triggers the new requirements. The upgrade will need to be commissioned under the new rules, including choosing an export pathway. This is something to factor into your planning if you are thinking about a battery add-on later in 2026.
Practical advice if you are getting solar in Perth
Coming back to the water tank analogy: WA's isolated grid needs these rules because there is no overflow pipe to a neighbouring state. But the rules are not punitive. They are about giving the grid operator a small safety valve in exchange for opening up the system to more solar, bigger installs, and future programs like VPPs that could actually earn you money.
Here is what I would do if I were getting solar or a battery installed in Perth right now:
Choose the future-ready export pathway
Unless you have a specific reason not to (no internet at inverter, shed install), the future-ready option is better in every practical way. You keep full DEBS access and open the door to VPP income down the track.
Confirm your installer knows the May 2026 rules
Ask them directly. If they are not aware of the new Western Power technical requirements, CSIP-AUS protocol, or the two export pathways, consider that a warning sign. Any SAA-accredited installer working in Perth should be across this by now.
Check Wi-Fi coverage at your inverter location
For the future-ready pathway, your inverter needs a reliable internet connection. If it is going on an external wall or in a garage far from your router, you might need a Wi-Fi extender or ethernet run. Discuss this with your installer during the site assessment.
Consider battery-readiness even if not buying one yet
If you are installing solar now and might add a battery later, the battery upgrade will trigger the new rules. Make sure your solar system is commissioned under the future-ready pathway from the start, so the battery add-on is straightforward.
The honest take
The new WA solar rules are not the dramatic change that some in the industry are making them out to be. For most Perth homeowners getting a standard solar or battery system, the practical impact is minimal: your installer configures a few extra settings, your inverter connects to Wi-Fi, and you tick a box saying you accept Emergency Solar Management. In return, you get full DEBS access and a system that is ready for whatever grid services emerge over the next decade.
WA is an isolated grid doing something sensible to manage an unprecedented level of rooftop solar. The water tank needs a safety valve. ESM is that valve. South Australia has had the same thing for six years, and it has barely been used.
The 30 kVA standard connection is genuinely good news. The two-pathway model gives you a clear choice. And the technical requirements are things your installer should be handling regardless. If you are in the market for solar or a battery in WA, the May 2026 changes are not a reason to hesitate. They are just something to be aware of when you are comparing quotes and rebates.
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Email: hello@whysolar.com.au
Tel: +61 455 221 921
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Written by
JaySolar Evangelist
Passionate about making solar simple and accessible for every Australian household. Jay breaks down complex energy topics into practical advice so homeowners can make confident decisions about solar, batteries, and energy independence.
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