Secret Harbour in numbers
Large houses, young households
98.7% separate houses, 87.5% with four or more bedrooms, and a median age of 34 at the 2021 Census.
Mostly owned with a mortgage
61.0% of homes had a mortgage, 18.4% were owned outright and 19.5% were rented.
A harbour in name only
The suburb sits on Warnbro Sound in the City of Rockingham. Its name, approved in 1984, comes from a marina development that never went ahead.
Solar and batteries in 6173
The Clean Energy Regulator counts 3,422 small-scale solar systems in postcode 6173, and 354 solar batteries recorded from July 2025 to September 2026.
Network: Western Power
Western Power has trialled washing insulators in Rockingham to cut pole top fires, and plans to treat or replace insulators at more than 100,000 locations by mid 2027. Outages and fallen lines: 13 13 51.
Will the supply carry what you're adding?
Since 11 April 2023, a standard home on Western Power's network gets 63 amps on single phase, or 32 amps per phase on three phase. If new circuits or load would take the house past that, the electrical contractor has to assess the demand and apply for an upgraded supply.
The test is the hottest afternoon of the year, not an average day. Perth averages 26 days above 35 °C, and that's when ducted cooling, the oven, a pool pump and a car charger all want power together.
Going to three phase
A registered electrical contractor lodges a preliminary notice, Western Power confirms three phase is available at the property, and then the application goes in. Once it's accepted, Western Power says the disconnection and reconnection takes 5 to 7 weeks.
Three phase also changes the solar maths. Western Power allows up to 30 kVA of solar and battery inverter capacity per home, but only 15 kVA on a single phase connection, which a big roof with a battery can reach.
Ask before you add a big load
- What's the house's total demand with everything running on a hot afternoon?
- Does this need an upgraded supply application, and will you lodge it?
- Is three phase available on my street, and how will we find out?
- Does the switchboard need a circuit breaker main switch?
- Can I see your EC contractor number, and the EW licence of the electrician on site?
If we were adding to a Secret Harbour home
We'd ask for a written load calculation before choosing any equipment. If it shows you're close to the single phase limit and more is coming, we'd start the three phase process early, because Western Power's part alone takes weeks.
Want a specialist to sort it?
Tell us the job and your postcode. We match the licence-checked local electrician who does this kind of work, and they call you. No ring-around, and your number goes to them alone.