AES: Advanced PV Diagnostics: I-V Curves

I-V curves are the basic graphical representation of performance of PV cells, modules or strings: measuring them can allow for insights into performance issues that are difficult, if not impossible, to see with other means. While field-use of I-V curve tracing has been in decline, it is still commonly used and – even if you never use an I-V curve tracer –  being able to "think like a module," will help you immensely in troubleshooting, determining the root cause of issues spotted through other means, and in understanding why PV "acts" the way it does.

This lesson starts with the basics of I-V curves, addresses field use of tracers, and quickly builds to an advanced discussion of good, bad, and ugly curves, what they mean, and what causes them. This is critical information for the well-rounded O&M professional.