There is always value in solar power, for both your wallet and the world*. But if you’re referring to value in terms of the physical solar panels you see on the roof, a recent study sponsored by the U.S. Department of Energy via the Lawrence Berkeley National Laboratory† shows that buyers are willing to pay more for a home with a solar photovoltaic system -- in some cases up to $15,000 -- but the study only included properties with solar panels that are owned.
It’s important to note, however, even if a buyer pays a little more for a home with solar panels, it is unlikely it will compensate you for the full purchase cost.
Lease or PPA programs are still fairly new, therefore the effect on home values is not yet known. Real estate professionals, including appraisers, agree more research is needed.
However, the benefits of long-term savings that a lease or PPA provides is for the duration of the solar service agreement -- and that in itself is valuable.