Rooftop solar panels are growing in number! In 2001, 118 solar panel installations occured, in 2017 there were 170,710! More information about that here.
But if you are wondering how much of the solar boom is in Victoria, the Sydney Morning Herald has published the top solar postcodes in Victoria and NSW.
It is interesting to note that in Victoria, the largest growth of solar rooftop installations is in a ring around Melbourne city itself. Whereas in NSW they are more concentrated far away from Sydney. Click here to get an idea of which suburbs are solar postcodes.