I think if you live off-grid a dedicated solar air conditioner might be a nice add-on but if you live on the grid, all modern AC systems are very efficient. With regard to energy saving, the most important thing to know is that by far, the least expensive way to lower energy bills is not minimizing usage or installing solar, it's maximizing insulation. It also makes a house very quiet and comfortable.
I studied Passivhaus design and worked with my wife who is a home builder to design a zero energy home. That is, a home that produces more usable energy than it consumes. It took over three years to build because no one at the city cared about super insulating a building or wanted to approve building methods that were non-standard. This is what I heard over and over again: Why not just install more solar to offset your energy usage?
Because, first do no harm. Apparently this is a complex idea.
