I knew I couldn't have been the only person here who thought that way.
From the original article about the installation itself, they use 17,400kWh per annum - about 47.7kWh per day. This is a staggering amount, even considering that they do work from home as well and have two teenage daughters living at home. By their own figures, their $38,000 solar installation only covers half that electricity (although about three quarters of the bill). As I'm sure NuShrike wondered, what the hell are they spending that electricity on? Do they run the air conditioner all the time? If so, wouldn't they be better off buying ceiling and wall insulation and some decent curtains?
My housemate has been considering a photovoltaic installation at home. (Since the Australian federal government suddenly pulled the rug out from underneath the $8000 rebate, I don't know whether he's still considering it.) By my measurements, he'll waste at least half of the electricity they generate on standby power for the computers and such, and nearly as much again on halogen downlights for the main living area. He's just not in the mindset that having PV power means being more responsible for electricity use. In other words, I suspect he believes that it will give him more electricity to spend as he pleases (invoking Jevons' Paradox, as NuShrike suggested), whereas the sibling post by hoojus shows how easy it is to develop the mindset of having less and using it more efficiently.
Of course, if you can save that amount of electricity, but without solar panels and for a fraction of the cost, it hardly seems worth bothering. You can still have both, though, even if it means a few new habits towards cleaning up after yourself.
Oh, and NuShrike, the idea of scaling renewable energy, rainwater catchment and the like for a community is a fantastic idea and one I have been hoping would see a bit more support. Let me know if you've got any ideas.