SolCool is an interesting looking one to watch. They are supposed to be releasing a "hybrid" air conditioning unit. Low power requirements, including a provision for "onboard" (part of the unit) or remote mount backup batteries. It supports DC operation during power outages and can even provide UPS (uninterruptible power supply) services to other devices.
If it winds up being what they claim, this could be an interesting device for onboard (a boat) use. Its fairly small (24" square and 48" high).
A "more information link" is available.
Harnessing the power of the sun, the SolCool 110/12volt Hybrid System combines innovative design with proven technologies that delivers fresh, clean and reliable comfort at a greater than 75% savings in energy consumption compared to most conventional AC Units in the Two Ton Capacity.Â The SolCool is the only AC unit that is pre-wired to take Solar, DC Lighting and Fan Options.