https://www.energyvanguard.com/blog/will-shading-your-air-co...
Moneyquote: "The temperature of the surrounding air has a much bigger effect on cooling efficiency than direct solar gain, and the volume of air pulled in by an air conditioner is huge."
An AC Condenser sitting in the Sunlight will naturally be a lot hotter in temperature than one sitting in the shade. For example park your car in the sunlight and then park your car in the shade? Where will the surface of your vehicle be hotter/cooler? It has nothing to do with air temperature at this point. It is the heat of the sunlight that is raising the temp of the coils in the condenser just like it would raise the temp of the surface of a vehicle parked in the sun instead of the shade.
I live in TX. I have some experience with this.
This means that you can save at most 5% by putting the radiator in the shade.
(Metal sheets heat up quickly in the sun because they have low heat capacity. They also cool down quickly if you blow on them with a fan. Just because something feels "hot", it doesn't mean that a lot of energy is stored inside)