Photovoltaic (PV) systems are installed by several types of market participants, ranging from residential customers to large-scale project developers and utilities. Each type of market participant frequently uses a different economic performance metric to characterize PV value because they are looking for different types of returns from a PV investment. Choice of economic performance metric by different customer types can significantly shape each customer's perception of PV investment value and ultimately their adoption decision. In this book, PV economic performance is characterized for three ownership types: residential customers who purchase their own PV systems, commercial customers (for-profit companies) who purchase their own PV systems, and residential and commercial customers who lease PV equipment or buy PV electricity from a third-party company.