A Power Purchase Agreement (PPA) is a contract between a client and an energy service provider, whereby the client agrees to make available his/her property to host the energy generation system as well as the option to purchase power generated from the system. Power purchase agreements range from 8-20 years, during which predictable and stable increases in electricity tariffs are guaranteed. Where applicable, additional generated energy can be sold back to the utility company. The roles of each participant in a typical Solar PV PPA are shown in the image below.