I reckon at least three

I have an emporia energy meter. While I can't answer your question exactly, I have sprayed mine with a hose during the hottest part of the day and watched the power usage drop a decent amount. So I imagine as long as the shade wasn't too expensive it'll pay for itself.

Sprayed it down with the hose again. Pic added showing energy usage drop. Doesn't last long from water, but does show it not working as hard when cooler.

Sadly there are just too many variables in play. Many other changes have been made to help keep costs down such as different thermostat settings, extra insulation, and duct sealing. It does all add up to quite a bit of savings.

https://www.aceee.org/files/proceedings/2002/data/papers/SS02_Panel1_Paper24.pdf

Shading the compressor can help but it can also hurt.

Those units can draw enormous amounts of air. Unless the shading covers a very wide area around the compressor, it's likely to mostly pull in air that wasn't shaded and is still at normal ambient temperature.

If the shading obstructs airflow, it can reduce the efficiency of the unit.

Not going to give an educated guesstimate, but I do know our ac unit is in full shade of trees, with not much greenery around. It is probably 20 years old. We were told, ten years ago by a repair man, it was close to kicking the bucket, yet it's still going.

My neighbor, has the same unit, newer, leas than ten years old unit, in full sun with bittersweet growing all around it. Last summer they spent half the time trying to fix it, and this year I saw them install window units..

I'm guess, it helps to have it shadded with no plant debris. Purely anecdotal.

Knock on wood oh boy..

This is what I came up with. I'm not seeing any heating of the siding it's hard to tell on the sail as it's in direct sun. Also the unit is just under the corner of the sail so air can definitely get up and around. There's about F10* difference between the siding in direct sun and the condenser.

I doubt it. That's quite far and it's open so there's plenty of room for it to spread out. You wouldn't want part of your building to be in the air stream because the air from the condensing unit would heat it up, but it's fine if the tarp gets warm.

Heat rises so the plume these put out really is tall, the buoyancy of air does most of the work – put a fog machine next to it and you'll see it reach higher than the house.

The biggest benefit here is probably the shade to the siding, I'd focus on that (read: more trees) going forward instead of a black mesh shade that will absorb more sun and radiate heat back out.

Snow weighs quite a lot! So it must come down after a/c season is over. This was $20 4-5 years ago. I wish retractable shades were in the budget, that would be awesome.

It’s a sad reality when people assume having an HOA is a given.

Feel bad for people subjected to it but I’d never purchase a property under the thumb of an HOA. Sucks how ubiquitous they have become.

My neighborhood is just too dull to have one I guess. Although once per month the city workers come and pick up leaves and sticks if you place them by the curb, which is pretty exciting.

Not all HOAs are bad... mine pretty much only exists to take care of our neighborhood pool, they've even loosened some of the few restrictions that had been in place since the 70s (restrictions on the type of fencing or sheds has been lifted). And it tends to run with a flat budget so our rates are very low for the area.

Assuming they live in an HOA. Also, this looks like a backyard. HOAs don’t typically (at least in my experience) have domain over the back yard.

As expected for someone who uses a heat pump!

By keeping the sun off it, that helps with keeping the equipment cool which the radiator is part of so there's less heat the fins have to dissipate no?

It's lasted 4 years so far and was only $20! It's a nylon mesh material that let's water flow right through without absorbing it so it doesn't get too heavy.