Do the math prior to investing in solar power. Not every location is a good bet to deliver energy savings. The best option is to look into the costs and the potential earnings (based off your sun conditions) to see what the costs will really be like. Sometimes, it'll be way more costly to use solar.
If you think you might need to replace your roof in the near future, hold off on installing solar panels. Solar panels can be difficult for some roof installers to contend with, and this means a more difficult and increasingly costly roof repair bill. If you can afford to wait on the panels and replace your roof first, this is the way to go.