RE Grid power being cheaper than you can make.

If you look at the breakthroughs IN THE LAB, over the last say 9-12 months (the first of which are coming on line now), solar power will not only reach the "break even point" in the next 3 years or so, but should actually become cheaper in many locals than buying power, with 2 main assumptions.

The first is that you don't have to pay for the land to put up your solar array - with that, all bets are off. You are already paying for the land your rooftop covers, so...

The second is that you don't really try for 100% "off grid". Sizing your array to try to handle peak load, particularly at NIGHT (read VERY large battery banks), or huge arrays if peak draw is during the day (rare in a home situataion, where you go to work) can really make the the ROI point of putting in a system exceed the life of said system (assume you will have to replace the cells in 20 years, batteries every??)

The break even point will change from location to location. From what I understand, on Long Island, in LIPA's area, it already pays with the rebates that LIPA offers. As far as I can tell, here in ConEd's area (some of the most expensive electric in the country), the ROI is negative, because there is no rebate

I presonally research the ROI about once/year, becasue as soon as the ROI is positive, my roof will have a set of cells