WA's new inverter rules from May 2026: what changes for Perth solar owners

Since 1 May 2026, every new or upgraded solar and battery system connected to WA's main grid (the SWIS) follows updated inverter connection rules. Two things change. You can install a much bigger system under a standard connection: the aggregate inverter cap is now 30 kVA, so systems that used to need an expensive non-standard connection now fit under standard rules. But a system without remote-management capability gets its exports capped at 1.5 kW. Your own self-consumption, the solar you use inside the house, is not affected either way.

If you install now with a compliant, remotely manageable inverter, none of the downside applies to you. The rest of this guide explains who is affected, what the hardware has to do, and why WA built the rules this way.

The two numbers that matter:

• 30 kVA is the new aggregate inverter cap under a standard connection (single-phase inverters are capped at 10 kVA). Bigger systems, less paperwork.
• 1.5 kW is the fallback export limit for a system with no remote-management path. Fit a compliant, connected inverter and you export at your managed tier's limit instead, which is well above the fallback but still subject to Synergy's ongoing export-management rules.

What actually changed on 1 May 2026?

Two shifts, one better and one stricter.

Bigger systems under a standard connection. The aggregate inverter capacity limit under a standard connection is now 30 kVA (single-phase inverters are capped at 10 kVA). That is a large jump. A 10 kW inverter used to trigger an expensive non-standard connection application. Now a system of that size sits under the standard rules, which makes larger residential systems in the 10 to 13.2 kW range practical without the extra paperwork and cost that used to make them uneconomical for many households.

Remote management is now the price of full export. Every new inverter needs remote disconnection and reconnection capability, and Synergy can curtail your exports during grid-stress events through its Emergency Solar Management (ESM) mechanism. Western Power sets the network's export-limit framework separately. A system that has no remote-management or connectivity path defaults to a fixed export cap of 1.5 kW. That is close to nothing: a 6.6 kW system pinned at 1.5 kW would spill most of its excess generation instead of exporting it.

Will my solar exports really be capped at 1.5 kW?

Only if your system has no remote-management path. The 1.5 kW figure is the default for the lowest connection tier, the one with no connectivity and no remote management, not a penalty for failing a specific standard.

In practice your installer sorts this out before connection. A compliant inverter with the right settings and a connectivity path sits in a managed tier, exporting at that tier's limit, with curtailment reserved for the handful of genuinely stressed grid days each year. The 1.5 kW cap is what you fall back to if the system cannot be remotely managed at all.

If your current system already has a Western Power export limit, our guide to why Western Power caps solar exports in Perth walks through how those limits are set for your specific property.

What does a compliant inverter need to do?

To connect under the new rules and export at full rate, your inverter needs to be set up for remote management on Synergy's Supported Solutions List. In plain terms, that means:

• It is listed on Synergy's Supported Solutions List (your installer checks this).
• It runs AS/NZS 4777.2 with the Australia Region B settings.
• It supports remote export management (CSIP-AUS), so Synergy can curtail or reduce export during a grid-stress event under its Emergency Solar Management mechanism.

Most current-generation inverters from brands like Fronius, Sungrow, GoodWe and Enphase support remote management out of the box. If you're choosing hardware now, our Perth inverter brand guide compares the common options.

Why did WA go this way?

The SWIS is one of the world's largest isolated power grids. Unlike the east coast's NEM, WA's grid is not connected to any neighbouring state, so it has to balance supply and demand entirely on its own. When rooftop solar is generating hard and demand is low, the grid can become unstable.

Perth keeps setting minimum-demand records on sunny weekends. On those days there is so much rooftop solar and so little load that the grid operator needs a way to manage distributed solar and keep the frequency in a safe band. Remote export management is that lever.

So the trade is straightforward. You can install a bigger system, and in exchange Synergy gets a remote off-switch for your exports on the small number of days a year when the grid is genuinely stressed, alongside the network export-limit rules Western Power already applies. Our explainer on solar curtailment in Perth covers what a curtailment event actually looks like from your side.

What should I do if I'm installing solar now?

Here's the short version if you're getting quotes today.

1. Confirm the inverter supports remote management. Ask your installer specifically about AS/NZS 4777.2 compliance and CSIP-AUS remote export management. This is what keeps you off the 1.5 kW fallback.
2. Consider going bigger. The 30 kVA aggregate cap means a 10 to 13.2 kW system is now a standard connection, which improves the economics for larger homes and higher-consumption households.
3. Think about a hybrid inverter. Even if you're not adding a battery yet, a compliant hybrid inverter makes a future battery easier to bolt on with hardware that already meets the rules.
4. Ask about VPP compatibility. An inverter and battery that can respond to Synergy's signals can earn you a credit through a Virtual Power Plant. More on that below.

What if I already have solar installed?

If your system was connected before 1 May 2026, you're grandfathered. Your existing inverter and export limits don't change, and you don't need to do anything.

The one thing to know: if you upgrade or expand your system, the new framework applies to the whole system, not just the new part. So adding panels or swapping an inverter pulls the existing setup into the current rules as well. If that's on your radar, factor the compliant-hardware requirement into the quote.

How do these rules fit WA's battery buildout?

The inverter rules sit alongside a large grid-scale battery program in WA. The Collie Battery, built by Neoen, runs at 560 MW / 2,240 MWh and is among the largest batteries in Australia. On the same Collie site, Synergy's own 500 MW battery went operational in February 2026. More capacity is on the way across sites including Kwinana, Wagerup, Merredin and Waroona, with the Kwinana batteries already built.

The grid is being rebuilt around storage, both utility-scale and residential. Home batteries that join a Virtual Power Plant are part of the same design: the new inverter rules let Synergy coordinate rooftop solar and home batteries alongside the big grid-scale assets.

For you, that means VPP participation is likely to matter more over time. A battery that can respond to Synergy's signals during peak events earns a credit and helps steady the grid.

How much can a VPP actually pay?

Under Synergy's Battery Rewards VPP, activation events pay around 70 c/kWh, and the estimated credit works out to roughly $150 a year. What you actually earn depends on how often events fire and how much your battery has to give: events are capped (up to around 30 a year), so the credit varies household to household rather than landing on a fixed number. Our Synergy Battery Rewards guide breaks down how the payments work and whether it's worth signing up.

The quick checklist

Before you sign anything for solar or a battery:

• Confirm the inverter is on Synergy's Supported Solutions List and supports AS/NZS 4777.2 plus CSIP-AUS remote management.
• Ask whether the system sits in a managed export tier, not the 1.5 kW no-connectivity fallback.
• If you can afford the extra headroom, size up: 10 to 13.2 kW is now a standard connection.
• Choose battery-ready or hybrid hardware if a battery is anywhere in your plans.
• Ask about VPP eligibility if you want the Synergy Battery Rewards credit.

Related reading

• Solar panels in Perth: the complete guide: system sizing, panel brands and inverter choices for WA homes.
• Virtual power plants in Perth: what VPPs pay and whether WA is ready for them.

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Planning an installation? Our Savings Planner models payback under the current rebate framework and the larger system sizes now accessible under the connection rules.