Here’s a story from USA with 2011 prices for solar PV,  big bucks but…”That works out to $2,400 a year in gasoline savings and when added to the $2,500 in electricity bills we’re no longer paying each year, you get $4,900 in net cash flow savings. Divide that figure in to the net cost of the solar panel project and it works out to 5.96 years before break-even.”

>readmore> Gigaom