Yeah sounds about correct, 10 years to pay back.
A 1kw system can out put 1kW when there is full sun, which is about the same as your microwave consume if you had it on nuking your food. Or the same as 10 100w lightglobes all on together. So it can power some items but wont run your meter backward very often, unless full sun, and no one home using any power. It obviously can not make power at night so you are basically going to use your power that you may have made during the day at night.
I have looked into it because I like the idea of being green, but unless you have the cash lying around it really seems like a hard decision, as we look into the future (10 yrs if thats what it takes to pay back) renewable energy will be big business, how good and cheap is solar panels and other green power going to get. Well maybe not cheaper but hopefully more efficient for less outlay.
But then again who knows, if you want to be kind to the environment and you have some spare cash burning a hole in your pocket, I think it is a great thing, but a large outlay for something that is not going to pay for itself in 10 yrs.
