A UK-based startup is looking to breathe new life into a century-old technology that could power tropical island nations with virtually limitless, consistent, renewable energy. 

Known as ocean thermal energy conversion or ‘OTEC,’ the technology was first invented in 1881 by French physicist Jacques Arsene d’Arsonval. He discovered that the temperature difference between sun-warmed surface water and the cold depths of the ocean could be harnessed to generate electricity.  

OTEC systems transfer heat from warm surface waters to evaporate a low-boiling point fluid like ammonia, creating steam that drives a turbine to produce electricity. As the vapour cools and condenses in contact with cold seawater pumped from the ocean’s depths, it completes the energy cycle. 

How it works: