Aerial views of your rooftop

The above photo is taken from Nearmap (an online photo map site) – it’s a massive PV installation I saw from the train on the north side of Brisbane a few weeks ago. When I got home I checked on Nearmap what it looked like from the air – quite impressive. There’s panels on all the car-park roofs as well as the main buildings (seems to be some sort of Qld. government facility).

Anyway, as most PV system owners are aware of, there are a couple of online resources you can use to see what your roof looks like and even measuring tools to get an idea of how many panels you could get up there.

The first is Nearmap (free for personal use). I believe they use aerial photos taken from planes and give very good resolution if you’re in a populated area. They update their views every month or so and have this neat feature where you can go back in time to see the same area or house as it was the previous times they took photos there (historical view). There’s only a couple of downsides to Nearmap – outside of built-up areas their coverage is fairly poor and if you’re searching for a particular address you’re out of luck. There’s a lot of street names missing from their search facility and no house numbers. So it’s OK if you know what you’re looking for but if you only have an address then what you need is Google Maps.

Google Maps is great in that you can search for a particular address and most of the time it comes up with the goods (although I have been on one or two wild goose chases following roads I thought were thoroughfares only to find out they were dead-ends). It also has

> the intuitive Google way of trying to guess your address which can be useful if you don’t know the suburb or exact spelling of the street etc. Sometimes you need to turn off the satellite view and just look at the map view to check the property boundaries with respect to the house numbers as they can get a little out of alignment. And there’s also Streetview to give you an idea of what the house looks like from the road.

Google Maps has greater

coverage than Nearmap, especially in the regional areas, but the resolution is usually not as good and their maps are not updated nearly as often as Nearmap. Also, if you need to use measuring tools you need to switch to Google Earth.

Note that maps for both these sites face true north, the optimal orientation for solar panels, so you’ll get a good idea of what panel orientations are possible on your roof.

There’s been a bit of flack (and rightly so) around some solar installation companies not doing a site inspection before they install the PV system, they’ll try to use Nearmap and/or Google Maps to check the roof area and work out what size system will fit. This might be convenient for the solar company but apart from it not complying with the CEC guidelines (meaning they’re not strictly eligible to claim the RECs/STCs) it also means they’re missing out on so much information relevant to whoever has to actually do this installation.

Aerial views won’t give you any information about the compliance of your meter box, shading effects of nearby vegetation (overhead images only give you shading info for one time of the day), any cable run issues and so on. So if you’re thinking of getting solar installed make sure the company sends somebody around to check the site and take photos (either an installer or trained technician or even a trained salesman if there is such a beast). Software is great to get an overview of what’s possible but is no substitute for a site visit.

Any other sites out there that show aerial views? Drop a note in the comments.