Over a Century in the Making: A Brief Journey Through OTEC’s History

The idea of harnessing the ocean to generate electricity may seem groundbreaking, but in fact, the principle has been around for over a hundred years. Ocean Thermal Energy Conversion (OTEC) was first proposed as a concept by Captain Nemo in Jules Verne’s 20,000 Leagues Under the Sea.

While fictional, the idea gained scientific credibility in the early 1880s when French physicist Jacques d’Arsonval (image above) developed the first practical system for using ocean thermal gradients to generate electricity.

However, it was only several decades later that the first OTEC plant was built. In 1930, Georges Claude, a student of d’Arsonval, installed the first OTEC facility in Cuba (image below). His experimental structure successfully demonstrated the concept but was unfortunately destroyed by a storm. This setback stalled further developments for nearly four decades.

During the 1970s and 1980s, amid the global energy crisis, the United States and Japan led experimentation with OTEC technology. In 1979, American researchers built the first OTEC plant capable of producing reasonable amounts of electricity—roughly 15 kilowatts of net power. This so-called ‘Mini OTEC’ (image below) was a closed-cycle system mounted on a U.S. Navy barge a few kilometers off the coast of Hawaii.

Following this breakthrough, in 1981, Japanese businesses launched another experimental closed-cycle OTEC plant in Nauru. This system produced 35 kilowatts of net electricity, marking another milestone in advancing OTEC technology.

Since these early experiments, researchers have focused on improving heat exchanger efficiency and developing techniques to reduce saltwater corrosion of system components. Over the years, other small-scale and non-commercial implementations have been tested worldwide, contributing to the refinement of OTEC technology.

otec present and future

OTEC history is being written right here at Global OTEC. We are pioneering the next phase of OTEC development with the first commercial floating OTEC system, our OTEC Power Module®.

We are also leading a pan-European consortium called PLOTEC, developing and testing in a real environment a floating storm-resistant structure for OTEC.

As the technology moves from experimental projects to real-world applications, its potential to revolutionise renewable energy continues to grow. With over a century of research and development behind it, OTEC is set to become a key player in the global transition to clean, sustainable power.