What is the difference between a PPA and leasing?
In short, a solar lease is where you pay a fixed month or lease payment, which is calculated using the estimated production of the system, in exchange for the right to use the PV system.
A solar PPA differs from this in that, instead of paying to rent the PV system, you agree to purchase the power generated by the system at a set price per kWh. You rent your roof and buy the discounted solar electricity that is generated, rather than investing in a solar PV system of your own.