{"id":98123,"date":"2026-03-10T06:03:17","date_gmt":"2026-03-09T20:33:17","guid":{"rendered":"https:\/\/www.solarquotes.com.au\/blog\/?p=98123"},"modified":"2026-03-08T09:24:16","modified_gmt":"2026-03-07T23:54:16","slug":"was-big-change-to-inverter-rules-kicks-off-in-may","status":"publish","type":"post","link":"https:\/\/www.solarquotes.com.au\/blog\/was-big-change-to-inverter-rules-kicks-off-in-may\/","title":{"rendered":"WA\u2019s Big Change To Inverter Rules Kicks Off In May"},"content":{"rendered":"

\"New<\/p>\n

Western Australia is updating the technical rules for small-scale solar and battery systems, with a new generous inverter size limit to be introduced from 1 May 2026.<\/p>\n

How Are WA Rules For Solar And Batteries Changing?<\/h2>\n

If you already have solar, nothing changes \u2014 unless you upgrade. But if you\u2019re installing a new system, or adding a battery or extra inverter capacity after that date, your setup will need to comply.<\/p>\n

Importantly, these changes apply only to systems connected to the South West Interconnected System (SWIS) \u2014 the main grid covering Perth and most of WA\u2019s population and operated by Western Power. They don\u2019t apply to Horizon Power networks in regional and remote WA.<\/p>\n

Larger Systems Allowed Under One Combined Cap<\/h2>\n

From May 2026, homes and small businesses on the SWIS can install up to 30 kVA of total inverter capacity under a standard connection.<\/p>\n

That 30 kVA refers to the combined rating of all inverters on the property \u2014 solar and battery added together. It\u2019s not about panel size or battery storage; it\u2019s about total inverter output.<\/p>\n

Under current Western Power rules, solar and battery inverters have effectively been treated separately. A home could install a 10 kW solar inverter and later add a 10 kW battery inverter without those ratings being assessed as a single limit.<\/p>\n

From May 2026, all inverter capacity on site will count toward one 30 kVA aggregate cap.<\/p>\n

So a 10 kVA solar inverter, 10 kVA battery inverter and 5 kVA additional inverter would total 25 kVA \u2014 within the new limit.<\/p>\n

Single Phase Gets a Big Boost<\/h3>\n

The same 30 kVA cap applies to both single-phase and three-phase connections.<\/p>\n

Currently, single-phase homes are limited to 10 kVA, while three-phase sites are allowed 15 kVA. The new framework gives single-phase households the same inverter headroom as three-phase properties \u2014 flexibility not currently seen in other states.<\/p>\n

Export Control Becomes Mandatory<\/h3>\n

From 1 May 2026, all new or upgraded systems on the SWIS must include either:<\/p>\n