Electricity from Sunlight, 2nd Edition

3PV Modules and Arrays

3.1 Introduction

Modules and arrays present photovoltaic (PV)’s face to the world, as well as the sun, and the technology’s reputation depends crucially on their technical performance, reliability, and appearance. They must be designed and manufactured for a long and trouble‐free life. The solar cells they contain need careful encapsulation to provide mechanical strength and weatherproofing, and the electrical connections must remain robust and corrosion‐free.

Most PV modules are provided with aluminum frames to give extra protection and simplify mounting on a roof or support structure. Modules without frames, known as laminates, are sometimes preferred for aesthetic reasons, for example, on the façade of a building where reflections from metal frames would be unwelcome. A group of interconnected modules working together in a PV installation is referred to as an array. We mentioned PV modules briefly in Section 2.1, noting the module areas required for a given power output using different cell technologies, and discussed cell and module efficiencies. In this chapter we will focus mainly on electrical characteristics and effective mounting to capture the available sunlight. But first, a few words about module sizes and designs.

For a given level of solar cell efficiency, the rated power output of a module is proportional to its surface area. As we noted in Section 2.1, about 7–8 m² of surface area is required to generate 1 kW_p using crystalline silicon cells, ...