For static storage of preps, consider a cheap refrigerator, with the thermostat set to the highest temperature. This wont be cold enough for perishable foods but should be fine for items like adhesive tape, jars of vitamins, first aid supplies, batteries and other preps that spoil rapidly in tropical heat.

Running costs for electricity should be affordable due to the relatively high thermostat setting and consequent limited running time.

The odd power failure wont matter much provided that it is on most of the time.