Can you feed into your household electrical system from a solar-cell array?

I'm not that well versred on solar cells--and wish that I was. I saw a show on TV not long ago (I wish that I remebered the network and the name of the show) where a couple chose to live in the Canadian wilderness and used solar panels (photovoltaic) in order to provide electricity to their house. It seems that everything was operated on a 12V DC circuit, because the incandescent lights were 12V lamps. I would guess that you would need some kkind of voltage regulator and storage batteries since the incident light that strikes the panels is not going to be constant in terms of luminescence.