Most leases offer a buy option after a 5 or 10 year period, be sure to read the fine print in the contract. Leases generally have a small interest rate / annual increase of 2-3%, well worth it when considering you can generate your own power, and dramatically lower your electricity costs.
Most lease contract agreements include cost of insurance, maintenance, and repairs / upkeep.
In comparing a lease to a PPA, usually a lease is structured so that if any power is generated over the written lease guarantee, you get to keep that power in the form of a bill credit from your utility provider.