3500 dollars will get you a solar powered AC unit called the SolCool Millenia. The sun powers the device and the hotter it is the colder the air can be pumped out. If it is still hot and AC is needed then the device has a 24 hour battery to keep things cool. Overall a nice idea I think which is both good for the user and the environment.
Via: OhGizmo
detailed working of solar powered refrigerator