Are you getting a lot of credits towards your solar purchase? How much is your electric bill per month usually? I remember awhile back, before there were government credits for solar panels and what not, it would take approximately 20 years for the cost of having solar panels put in to match the savings that they produced. Solar panels also lasted around 25 years back then as well though.
There are a lot of factors to whether it makes sense to have solar panels put in for your house. Like how much electricity you actually use, how efficient the solar panels you get and where you are, and the upfront costs that you have for the solar panels. If I had a regular 2000 sqft home in North County, and was getting the more recent solar panels; then it would generally be worth it if I stayed in the home for more than 15 years.
Hope that helps a bit. In generally, you just need to sit down and calculate everything when you get the estimate to see how long it will take for things to even out.
