Renewable energy sources are the go-to these days, as the world pushes hard to lower carbon emissions and mitigate climate change. One renewable energy source in particular has not been explored as much, with many deeming it a myth. Now, we’ll finally be able to mine it under the sea, as Europe has confirmed the 200-year-old myth. It’s officially a new era.

A brief overview of this renewable energy myth

You may have heard of hydro-energy and of geothermal energy, but have you heard of ocean thermal energy? It’s not a new concept, but much of it remains unknown. The concept is simple. The ocean has a low albedo, which is a surface’s ability to reflect sunlight. Now, sunlight hits the ocean surface, and 94% of the UV radiation is absorbed. The UV radiation excites the surface water molecules, creating a rise in surface temperature.

As the surface is heated, the ocean depths remain cold, which results in a temperature gradient. This temperature gradient can be utilized to power turbines, converting ocean thermal energy into electricity. So many of you might think, ‘Why haven’t we tapped into this source before?’

The fact is, many have tried before. According to AZoCleantech, French physicist Jacques-Arsène d’Arsonval first proposed the concept in 1881; however, technology was limited, so it remained a concept. In 1930, Georges Claude, d’Arsonval’s pupil, engineered an energy conversion plant in Cuba. In 1935, he engineered a second phase plant off the coast of Brazil, which was unfortunately destroyed by storms before it was economically feasible. Since then, funding has been a major problem, but now it could all change, as Europe has proven this almost 200-year-old myth.

Europe’s ocean thermal energy mine

Not only has ocean thermal energy conversion (OTEC) been proven to generate continuous power, but it also generates fresh drinking water and cold water for refrigeration. Since Claude’s prototype in 1930, no other large-scale plant has existed, except for a few more dozen prototypes here and there. Luckily, all of that is about to change!

Global OTEC Resources, a UK-based company, is going to deploy a 1.5 MW large-scale OTEC platform in the African island nation of São Tomé and Príncipe by 2025. The company obtained its certificate of approval for the installation methods of a cold-water riser. A cold-water riser is essentially a pipe that transports seawater from the sea to a seawater tank and back from an offshore OTEC platform.

“History is an important teacher, and we are committed to learning from it. Failure of previous OTEC projects highlights where we should exercise caution, so third-party technical due diligence from the earliest stage is important for our success.” – Global OTEC Founder and CEO Dan Grech

Expanding knowledge on ocean thermal energy

A pan-European trust, called PLOTEC, consists of Austria, Italy, Portugal, Spain, and the United Kingdom. PLOTEC is also presently busy with a project comprising the design and validation of an OTEC platform that can resist extreme weather conditions in tropical oceans, using a feasible cost model validated by a smaller prototype. The goal of the project is to gain and exchange knowledge regarding ocean thermal energy and its conversion, as well as to create more awareness of the concept.

“Since the ocean comprises around 70% of the earth’s surface it is a vast receiver and repository of solar energy. While waves, winds, tides, and currents are all forms of ocean renewable energy, which vary with time and season, conversely, an OTEC system permits the generation of constant power 24 hours a day, 365 days a year.” – International Energy Agency’s (IEA’s) Ocean Energy Systems (OES) technology collaboration program

Water and solar energy have gone hand-in-hand with many other power-generating designs as well. Hopefully, ocean thermal energy will become more popular as we gain more knowledge.