I have discussed this issue with my wife many times over the last couple of years. We refer to it as getting “Off the Grid”. She says, “How can you even talk about getting off the grid when you can’t remember to shut off the garage/bsmt lights.” Anyway, the advances in photovoltaics have improved dramatically. I understand we are at $5/Kilowatt down from $30 in the last few years. I hear when it hits $1/kilowatt, the industry will go nuts. Right now you have to calculate in a tax credit to see if it still makes sense. Also, thermal collectors have made great strides in recent years too. The old liquids that use to be used for hot water are obsolete; but the new ones are much more conductive; Enter new fancy stuff that is highly efficient. History tells us (Jimmy Carter Days) that if the stuff on the roof in any way harms the curb appeal, the net affect will be negative marketability-wise regardless of the system’s efficiency. There is a company here in Denver that is a leader in the industry on residential energy savings. Interestingly enough, the name of the company is About Saving Heat www.aboutsavingheat.com .
I’m not sure this was helpful, but I rambled for a while……