Photovoltaics is a term that refers to thin cells that have the ability to directly convert sunlight into electricity. This process occurs without the use of any moving parts, and the sunlight is free for the taking if it can be captured for useful purposes like heating water or air or producing electricity. As the cost of installing a photovoltaic array decreases, such systems become more economical and more popular. This article presents an activity that aims to teach students how to determine if a home is suitable for using photovoltaics, how to size a photovoltaic system, and how to estimate the payback period for installing a photovoltaic system. (Contains 3 figures.)