We recently installed a grid tied system that is off-grid capable should we encounter an extended power outage. After our rebate the system cost us about $40K installed. We have about zero'd out our electric bill and could easlisy survive days with out power or sunlight to refresh the batteries - we have the ability to run our portable generator through the system to charge the batteries.

With some conservation, and a few peak hours of sun light a day, we could function in our home with no forseen problems. I don't know about the complexities of wind turbines, but the solar system is fairly maintenance free. We went with AGM batteries that do not require checking fluid levels (etc) and should last us about 10 years if we don't let them run down below 50%.

I am still waiting to see if our County Assessor's office will decide that our 'improvement' requires them to up our tax basis - this would wipe out the cash savings on our utility bill and the system will never pay for itself.

There is a comfort level though, and in some respects we installed this system as a hedge against where energy rates are going.