OTEC. Oceanic Thermal Energy Conversion is not a new technology. However, costs have kept it from being developed into a mature technology. But with tremendous co-benefits, like desalinated water, nutrient rich water for aquaculture, and air conditioning, the technology may have a bright future indeed.
Since you need a decent temperature difference between surface water and the water pulled from the depths, the ideal places for OTEC are tropical islands near deep sea trenches. Places like Cuba, the Marianas, Jamaica, and Java…and mostly all between the tropic of cancer and tropic of capricorn.
But EDF scientist Rod Fujita says that heated wastewater plugins to OTEC systems may make it viable almost anywhere with cold enough sea water. As is, we’ll probably have to wait a bit for OTEC to come around in the tropics before becoming economically viable elsewhere.