We will now look closer at the circuits and electrical characteristics of modules and arrays. In Solar Energy Basics, you used module spec sheets to calculate power using voltage and current. In this module, you will be using those module specifications again, and looking at how the different voltage and current values included are important for determining how that module will operate under different conditions. Lastly, we will be looking at the design of both the internal circuitry of modules, and the circuitry of arrays of modules.

You calculated photovoltaic system sizes and outputs in Solar Energy Basics based on available insolation. Those insolation values were always based on the assumption of the array being set up at optimal conditions. On-the-ground conditions can often result in variations from the optimal design for capturing all the available insolation, such as the angle of a roof and the direction it is facing being fixed, or nearby trees casting shade onto part of an array. In this module you will learn how to account for the different sources of losses in insolation, because the overall productivity of a system design can change based on the positioning of the array, temperature variations, and shading on parts of the array. These variations in productivity need to be accounted for early in the planning phase of a PV system.

In the last content module of the course you will be working on equipment selection and system sizing. The previous modules on array siting, irradiance variability, temperature effects, shading losses, and circuit design will all come into play when you are designing a system. Additionally, you will be looking at site surveying, where those pieces of information are gathered, and permitting, where they are recorded and communicated along with the recommended system design.

The capstone project of this course will entail applying much of what you have learned in this course. You will need to design a PV system using commercially available components and calculate it's output under site specific conditions. You will have to account for the available solar radiation and losses due to the positioning of the array as well as due to shading. You will also need to design an optimal configuration to connect the PV modules with an inverter. Finally, you will evaluate a PV system design for both accuracy and safety.