# Does the load at where Pmp of a solar panel is oberved change with temperature?

After reading up on solar panels, I know that the max power that a Solar panel can supply ($$\P_{mp}\$$) will drop as the temperature increases. The $$\V_{oc}\$$ will decrease a lot more than $$\I_{sc}\$$ increases, so the Fill Factor will go down.

But this is the one thing I haven't been able to find an answer to. Say, $$\P_{mp}\$$ of a solar panel that has a temperature of 25 °C is observed at a load of 20 KΩ. Will the load where the solar panel has its $$\P_{mp}\$$ change at a different temperature, and if so, will it increase or decrease?

• As a general rule, maximum power output is when the load impedance is the same as the internal impedance. – Janka Jun 1 '19 at 1:17

Say, Pmp of a solar panel that has a temperature of 25 °C is observed at a load of 20 KΩ. Will the load where the solar panel has its Pmp change at a different temperature, and if so, will it increase or decrease?

Without any knowledge of solar panels you can deduce that

• If Pmp and Vmp decrease with increasing temperature and

• Imp remains much the same, then

• As Rmp = Vmp/Imp, R mp must decrease with increasing temperature.

Vmpp has a negative temperature coefficient (goes down when temp goes up). Eg, -0.37% / K.

Impp has a very small temperature coefficient (changes very little with temperature). Eg, -0.008% / K.

Therefore, yes, Rmp changes with temperature.

Impp and Rmp also change very dramatically when the amount of incident light changes. But Vmpp stays relatively constant with changes in lighting (when compared with Impp).