Zilch electricity required. Appropriate depending on the climate and water availablity:
Clay Pot Fridge.
http://en.wikipedia.org/wiki/Pot-in-pot_refrigerator
How to make one.
http://www.wikihow.com/Make-a-Pot-in-a-Pot-Refrigerator
Very humid here in the NT of Australia six months of the year. But gonna give this a try during the dry season.