AC is more than 100% efficient in heating the environment. This is unfortunate, but thermodynamics will win in the long run.
Heat pumps are more than 100% efficient at heating the house, which is what we want, and one of the places where we are on the same side as thermodynamics.
Fair enough, but direct heating of the environment is not of practical concern since it's effect is minuscule compared to GHG's. Point being, solar output is well correlated with A/C usage, which is a nice benefit and all that solar energy would be turned to heat anyway... so might as well have it cool your house :) Heat pump in the winter on the other hand, not so well correlated with renewables.
In the long run ACs are exactly 100% efficient at heating the environment. The extra heat is only temporarily displaced from the building being cooled, and will leak back in eventually.
There is heat generated by the system, and heat generated by the power generation used to power the system. It’s definitely not a neutral system - that’d be thermodynamically impossible ( increasing entropy without external energy)
If you power the AC with 100% solar shouldn’t there be no extra heat generated?
As in you’re merely absorbing some of the heat from the sun to then move existing heat around?
Frankly, even without solar power it wouldn’t generate “extra” heat directly over a long timescale, it would only accelerate the release of existing “heat” currently trapped in oil/gas/nuclear/etc.
There’s a fixed amount of sunlight hitting the earth every day, but not a fixed amount absorbed. A solar panel captures more heat than a white surface that bounces most of the light back into space. So the act of solar-powered a/c would still result in a net increase in global heat, unless you put the solar panel on top of something that was absorbing more heat than a panel does. I have no idea of the actual practical math of this - like does a black roof absorbs more or less than a panel? But solar energy isn’t impact free, even if we set aside panel manufacturing.
Once the heat is captured by the solar panel, I think you’re right using it for a/c is neutral - just moving heat around.
As for burning stored energy, that has to play into the heat dynamics of the globe. Like if you release it all at once it stops processes that would remove it from the atmosphere (animals and plants die), and it creates runaway heating feedback loops. there is some level of burning stored carbon that the planet can buffer and absorb and results in no change in global temperature. So burning stored energy in excess of that is a big problem. Like how you can sit or walk without noticeably sweating, but running causes you to have to actively cool yourself by sweating.
Heat pumps are more than 100% efficient at heating the house, which is what we want, and one of the places where we are on the same side as thermodynamics.