Demand for renewable-energy technologies is growing rapidly, requiring a greater number of skilled system technicians. Photovoltaic Systems is a comprehensive guide to the design and installation of several types of residential and commercial PV systems. The content covers the principles of PV electricity and how to effectively incorporate it into electrical systems. Numerous illustrations explain the concepts behind how PV arrays and other components operate, and photographs of actual installations show how components are integrated together to form complete systems. Content also covers the topics needed for solar installer certification by NABCEP. Photovoltaic systems is the essential guide to all aspects of PV systems. This second edition updates electrical requirements per the 2008 NEC® and expands the coverage of sun position, shading analysis, and computer modeling of system performance expectations.