OTEC Plants: Converting Thermal Ocean Heat Into Electricity

We have long searched for efficient methods of harvesting energy.  Most of our planet is comprised of water, and the oceans provide a bounty of resources including food, transport, and leisure; they are also a source of renewable energy.  The oceans vary in temperatures from the warm surface, to the cold depths where the sun never reaches.  This change in temperature can be harvested and converted into electricity by using a power station called an OTEC plant.  

What is an OTEC plant?

An ocean thermal energy conversion, or OTEC, plant is a power generating station that uses the variance in sea temperatures to create electricity.  The technology was developed in the late 19th century and there is currently only one operating plant in Japanese waters, although there have been several functional plants over the last century. 

OTEC plants can be on land, or near-shore in places where there is access to deep waters.  They can be mounted to the continental shelf at a depth of up to 100 meters, or they can float on off-shore facilities.  

Harvesting power from the ocean is another form of a renewable energy resource and alternative to fossil fuels.  The engines work 24 hours a day at converting natural temperatures of water into usable electricity. 

As a by-product of water extraction, the plants produce cold water which can be used for air conditioning and refrigeration.  They also desalinate seawater and produce distilled fresh water which is safe for human consumption. 

In History

A French physicist named Jacques Arsene d'Arsonval developed the OTEC technology in the 1880s and proposed to harvest the thermal energy of the ocean.  His student, George Claude took it upon himself to build the first plant in Cuban waters in 1930.  The first OTEC plant was generating 22 kW of electricity with its low pressure turbine before it was destroyed in a brutal storm. 

Following the Cuban plant's destruction, Claud build a second plant off the coast of Brazil.  It was destroyed by waves before it could generate enough energy to be measured. 

It was not until the 1970s when a successful plant was constructed in Naru Island, Japan. It became fully operational in 1981 and provided electricity for a school and several other buildings.  In the 100 years of OTEC's development, this was the first time that its generated electricity was sent into the power grid.  

OTEC plants are clean, green, do not produce any greenhouse gases and are renewable.  Renewable energy facilities like an OTEC plant can help counteract the damage we have done to the planet's ecosystem from burning fossil fuels and provide a cleaner form of electricity for the future.  At the moment, they are quite expensive to build and use a third of their own energy to sustain basic functions.  If they are to be functional on a larger scale, they will need to be much larger.  

Scientists and engineers are still developing OTEC technology and we may see a shift towards a greener, renewable ocean-based source of energy in the near future. 


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About avocado

I am a globe trotting visual artist who is also vegan. I've been living in Bali for the last few years and am currently in back in Canada learning how to stay warm.


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