Solar's pretty close to being cheaper than buying it from the local power company. Like, really, really close. Google's got a big fat bounty for reducing the transformer/inverter down in cost and size, that's the last step. Lithium battery tech is about to make a huge generational leap, solar panels are very nearly free (they pay for themselves in the first year), it's just the controller/inverters.
Hell if someone would sell a 2-Ton DC-powered Air Conditioning unit wired directly to some solar panels and an ultra capacitor, that alone would drop your power bill by 70% in the summer here in Texas and 30-60% during the rest of the year. Trickle charge some small batteries for daily stuff. Electronics just absolutely sip power these days. My 40" HDTV uses just 40 watts - that's one third of the power my 2.1 "home theater" system uses.
It might sound fanatical but other than my dish washer, washing machine, air conditioning and dryer, I don't think there's any one device that uses more than 100w of power in my house any more.