Any Renewable Energy system that uses solar modules must utilize a mounting system. Panel racks come in a variety of shapes and technologies. The two main choices are a "Tracker" or a "Fixed Rack." A Tracker is a device which keeps a set of modules always facing perpendicular to the sun. This can gain you additional charging hours. A Fixed Rack is any mounting system which holds modules at a fixed degree angle (like due South) and at a fixed latitude angle. These may have the ability to be adjusted throughout the year. Fixed Racks can include: Ground Mounts, Roof Mounts, Pole-Side Mounts, Pole-Top Mounts, and Boat/RV Mounts. To figure out which PV Rack you need, you only need to know which module will be used and how many.