Is a photovoltaic powered air conditioner neutral to global warming? Is my assumption correct, that

*

*Power generated by photovoltaic solar panels reduces heat energy
from the sun (according to the PV cell efficiency of around 20%) on
the area they cover


*An A/C converts 100% of the input energy to heat eventually


*Actually any powered mechanical device that doesn't store energy
will eventually transfer all input energy to heat because every
movement ends eventually, due to friction
If these assumptions are correct, is it correct to say that PV powered A/Cs are neutral to heat generation? The same goes then for EVs?
(Note I'm strictly about input/output energy conversion during usage - not the  production of the devices etc.)
 A: Your argumentation is correct.
Nitpicking: a minor non-zero effect might be caused by the darker "albedo" of PV elements vs. the typical earth surface, thus absorbing more of the sun radiation instead of re-radiating it. But, taking into account how little of the earth surface is covered with PV cells, this can surely be neglected.
And even the amount of energy directly consumed/produced by mankind isn't the dominating factor. Even if every single person on earth were constantly producing 10kW heat (and I think, in reality, it's much less), that would be $80\cdot10^{12}W$. Compared with an estimated $140\cdot10^{15}W$ solar radiation hitting the earth, this would be less than 0.1% additional heating, maybe increasing the surface temperature by 0.2K.
The climate problem is more related to changes in the properties of our atmosphere that reduce the amount of heat radiated from earth into space.
So, while your argument is valid, the more important benefit of your PV-powered A/C is that it doesn't use an atmosphere-changing energy source.
