Best Perth suburbs for rooftop solar

Gnangara tops the ranking, with 97.5 rooftop-solar systems installed for every 100 dwellings in its postcode, averaging 8.08 kW each. Across the 15 listed, the rate runs from 72.4 to 97.6 systems per 100 dwellings. These 15 suburbs came from a field of 95 eligible Perth suburbs.

Each eligible Perth suburb is scored on three factors, all of them rates: rooftop-solar installations per 100 dwellings (70% of the score), the average size of those systems in kilowatts, and how many systems went up in the past year per 100 dwellings. Percentiles are computed within Perth's candidate pool, so a suburb is ranked against the rest of the city rather than the national field. The top 15 are published.

The Clean Energy Regulator publishes installations by postcode, not by suburb, so every suburb inside a postcode carries the same figures. Ranking them individually would fill the list with near-identical clones of the same postcode, so each postcode appears once, represented by its largest suburb.

No, and the gap runs both ways. The count is of systems installed since 2001, so a system replaced or upgraded on a roof that already had panels is counted a second time, and small commercial systems up to 100 kW are counted alongside houses. Against that, the dwelling base is the 2021 Census. The figure is a good comparison between postcodes and a poor estimate of the share of homes with a working system today.

Three reasons account for almost all of them. The suburb may sit below the population floor; its postcode may have too few dwellings to put a rate on; or the postcode may have been built out so fast since 2021 that the dwelling count no longer describes it — in that case the rate measures construction rather than solar, and it is left out rather than published wrong. Apartment-heavy inner postcodes are also genuinely near the bottom: there is little roof per dwelling to put panels on.