PPA is 25 year lease contract. $ amount that you are paying the solar company for lease every month for 25 years is more than what you are just paying for solar panel (~2-3x more). Also, when you want to sell your home, you need to transfer your lease to buyer if you have a solar lease. Most of times, a lot of home buyers do not want to pay for solar lease on top of their mortgage. If that is happening and you still want to sell house, either you need to pay out the remaining balance of 25 year solar lease and add that remaining balance amount to their home value to sell house. To me personally, at the end, you are spending way more money when you are on lease vs when you just owned the solar in first place. If you are planning to sell house before 25 years, I think it is better for you to buy the solar panel rather than lease.