# Solar Module Voltage when bypass diode activate?

What happen to the voltage level when a solar module is shaded and one of its bypass diode is activated? Assuming this solar module has 3 bypass diodes.

I have been reading and can't seem to understand the theory. Should one bypass diode activate, I will assume the voltage should be 2/3 of the maximum Voc of a solar module?

Thank you.

## 1 Answer

Yes. If a group of cells can't keep its bypass diode reverse-biased, then by definition, the voltage across that group will be the $$\V_f\$$ (forward voltage drop) of the bypass diode.

• Thanks Dave. Wish to clarify what is $V_f$ suppose to stand for? – SunnyBoiz Nov 16 '19 at 9:03
• It's the forward voltage drop of the bypass diode, since if it isn't reverse-biased any longer, it must be conducting current in the forward direction. – Dave Tweed Nov 16 '19 at 12:51
• Cool! Thanks for the clarification! :) – SunnyBoiz Nov 17 '19 at 3:42