# Are solar panels considered a current source?

#### MikeJacobs

Joined Dec 7, 2019
226
So As I understand, solar panels although do generate a voltage, when placed under load the voltage collapses

So theoretical are pv panels considered more of a current source?

Thanks

#### nsaspook

Joined Aug 27, 2009
12,796
Yes, they are modeled as a current source with a few extra components.

#### oz93666

Joined Sep 7, 2010
739
Well , that's no different from any current source .... put a load on any battery and the voltage will 'collapse ' ...

With solar the voltage collapses rather quicker and the trick is to get the right load to extract most power, this occurs at about 75% open circuit voltage .

EDIT ....Ah..I see it is different from a battery which is modeled as a Voltage source , not a Current source ! What's going on???

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#### crutschow

Joined Mar 14, 2008
34,047
A solar cell can be modeled as a (poor) current source with a low (and variable) shunt resistance, as well as a series resistance.
Thus it's current output will be relatively constant with small changes in the load resistance.
I see it is different from a battery which is modeled as a Voltage source , not a Current source ! What's going on?
A battery is modeled as a voltage source since it typically has a constant voltage output with a low series impedance.
The output voltage varies only slightly with different load impedances, but the current varies with the impedance.

A current source has a relatively high output impedance.
The output current thus varies only slightly with different load impedances but the output voltage varies with the load.

#### Externet

Joined Nov 29, 2005
2,182
Can the words 'impedance' in post above be replaced with 'resistance' and still be right ?

#### TeeKay6

Joined Apr 20, 2019
573
Can the words 'impedance' in post above be replaced with 'resistance' and still be right ?
The topic is models. Could a model be created using only resistance? Certainly. Could a model be created using elements comprising an impedance? Certainly. Could a resistance be considered as an instance of impedance? Certainly.

#### crutschow

Joined Mar 14, 2008
34,047
Can the words 'impedance' in post above be replaced with 'resistance' and still be right ?
If the signal/currents are DC then yes.