A team of scientists have released an intriguing study on harnessing OTE in the Pacific n the Journal of Geosciences.  Hyeon-Ju Kim, Ho-Seung Lee,  Seung-Taek Lim and Michael Petterson have authored "The Suitability of the Pacific Islands for Harnessing Ocean Thermal Energy and the Feasibility of OTEC Plants for Onshore or Offshore Processing"

..."An engineering principle, termed Rankine cycle power generation, can use the thermal gradient to generate power. Whilst at the moment OTEC is not a large-scale commercial reality, a number of organizations are developing small-scale OTEC plants, both land and sea-based, with the vision that, one day, the plants will become large enough to attract commercial interest..."  Read here