First I want to qualify this as pertaining to air conditioning in Florida only. It seems to me at this time it might be as cost effictive to install an air to air standard heat pump and use the savings over the price of a geothermal unit to install a photovoltatic solar system to lower energy use. A grid tie system with micro inverters is pretty simple and Panels with inverters are available to me for about $2 a watt. I could spend $10,000 on panels and maybe have lower energy bills that a geothermal system. Plus in the winter when the AC is not running still have the solar offsetting the other house electric usage. Any thoughts on this idea?

Don't confuse panels with inverters at $2 / Watt with cost of an installed, inspected, safe, and code compliant PV system

Depending on where you are in Florida, the case for geo may not be as compelling as it is further north. Geo does have a distinct advantage in coastal application s since it avoids corrosive sand and salt spray

I am looking at not much more than $2 a watt installed in this location. No racking is involved and it is an add on to an existion system.

Where are you?