# Big photovoltaic current

A photovoltaic cell is just a photodiode connected to a resistor.Now if simulate this circuit – Schematic created using CircuitLab

I put many photodiodes in series , this would create a bigger current than in the first schematic right? simulate this circuit

If the photodiodes are parallel: simulate this circuit

then we can create an equivalent circuit: simulate this circuit

and currents will cancel each other out.

• Comments are not for extended discussion; this conversation has been moved to chat. Any conclusions reached should be edited back into the question and/or any answer(s). – Dave Tweed Dec 15 '19 at 18:12

In my diagram don't they cancel each other out? Is the equivalent circuit wrong somehow? There is no external EMF besides those two photodiodes. simulate this circuit – Schematic created using CircuitLab

Figure 1. (a) has no load. If the voltages are balanced no current would flow. (b) has a load. Current will flow.

• Photodiodes in series will give a higher voltage but the same current.

• In parallel they'll give higher current at the same voltage (as a single unit).

The current of 4 cells will not always be higher then the current of 1 cell. It does depend on the U-I characteristic of the PV-cells and the load.

F.e. if the 100 Ohm resistor is choosen to get the absolute maximal current of ONE PV-cell, 4 identical pieces in series will not be able to generate more current by definition.

Voltage sources put parallel with identical voltage (parallel, not anti-parallel) will not cancel out each other. I.e., the voltage is the same as with 1 voltage source, but no current will flow. The statement, that the current will be canceled out is correct. This case is fully symmetrical, no current can flow in either direction since the symmetry would be broken.