Defaults are invented for illustration: they are not measurements and not a real module. The calculator uses a simple series rule. Every module has the same current. A substring is a group of cells with one bypass diode. A shorted diode removes its substring's voltage and adds one diode drop of reverse polarity. An open diode changes nothing in full light. With one substring shaded, an open diode limits the string current to the shaded share of light, so the open result is an upper bound on the loss: it can be well above what a full I-V model gives. Enter numbers with a point or a comma as the decimal mark. Whole-number boxes accept 1,000 or 1.000.