Solar Power Purchase Agreements (PPAs) are a financing model that has the potential to transition those operating as suppliers of energy-generating equipment to the role of the more traditional energy retailer. This transition will see solar installers mature commercially to become solar developers. PPAs have been around for many years and are widely used in the USA and are now being adopted by a number of Australian solar companies. How to define a solar PPA? What must customers and installers take into account when entering into these agreements? And what other options are there to finance a solar system?