You might be better off with a heat driven cooling strategies - kind of counterinuitive.
One method is to use silica gel to dehumidify incoming air. Heating the silica gel releases the trapped water and recharges it. The incoming air can be dried so completely that a swamp cooler is effective.
There are also water chillers that use an ammonia cycle with hot water and cool water.
Another way to go is a ground source heat pump. That will take some watts though.
