Hawaiian oceans could provide steady renewable energy

Researchers at the University of Hawaii at Manoa say that seawater from the Hawaiian Islands may be ideal for future ocean-based renewable energy plants.

 

The technology is referred to as Ocean Thermal Energy Conversion (OTEC).

 

It involves placing a heat engine between warm water collected at the ocean's surface and cold water pumped from the deep ocean.

 

The heat flows from the warm reservoir to the cool one, and the greater the temperature difference, the stronger the flow of heat. This can be used to do useful work such as spinning a turbine and generating electricity.

 

Although expensive, if the ocean temperature differentials are great, it could work out to be very cheap.

 

University of Hawaii's Gerard Nihous says that the warm-cold temperature differential is about one degree Celsius greater on the leeward (western) side of the Hawaiian Islands than that on the windward (eastern) side.

 

This small difference translates to 15% more power for an OTEC plant, says Nihous.

 

The research is published in the Journal of Renewable and Sustainable Energy.