Hi Ballabooyeah,
You didn't ask me, but I will give you my .02. I cool my GH with the open sides like you mentioned that the other GH uses. The sides roll up with a temp sensor. I have a double layer of plastic on the ends and roof. The growers here in south Florida, say that it helps for hot or cold. I have louvers that open on the ends with a thermostat, that lets heat out passivlly. I use 2 hp heat pumps on all my systems to keep the water temp where I want it. I also use fans on the sumps themselves to save some electric costs during the summer. The fans can only do so much with the humidity like it is here.
I tried the geothermal. It did not work for me. My grd temps during the summer were about 80, so that does nothing. From what I found you either have to have at least 10 degrees difference in ground temps or have so much under ground compared to what you have in tanks, it is not worth it. If I have to have 2-1 or 3-1 in the ground, I don't need it.
I just bit the bullet and pay the electric compnay
Matt