The ocean is full of mystery, captivating many researchers and explorers for centuries. While many have sailed across it, not too many have dared to dive down into its depths to tap it for answers to questions we’ve had for so long. Recently, Europe has been working to harness a secret energy buried in the sea, moving closer to turning a decades-old myth into a reality. Could this unlock the answer to our climate crisis and power the world? Or will it take many more years before we unlock its full potential?
From transitioning to renewables to confirming a long-held myth
The world has been transitioning to renewable energy sources in a global attempt to mitigate the effects of climate change. While many technologies have been based on the more common resources, such as solar, wind, and hydropower, there is one source that has been overlooked for quite some time, but it is swiftly expanding its development as we speak.
The ocean is a valuable power source with great potential to supply clean power to tropical regions. Many researchers and companies have been developing technology to harness the secret energy of the ocean, including a European one; however, a French physicist predicted this secret over a century ago. In 1881, Jacques-Arsène d’Arsonval foretold that “solar sea power” would be a sustainable power source by utilizing a closed-cycle system with a vaporizing liquid to drive a turbine. This concept became the basis for the development of today’s modern systems.
Harnessing the secret energy buried in the sea
A pan-European trust, called PLOTEC, has been making waves in the renewable industry with its design of a system that will tap the ocean for unlimited, clean power. This system will utilize Ocean Thermal Energy Conversion (OTEC), and its significance will be demonstrated by a scaled prototype. The prototype will showcase the ability to withstand harsh weather conditions in the tropical ocean.
How it works
OTEC produces electricity by harnessing the natural temperature difference between warm ocean surface water and cold deep ocean water. When the temperature difference reaches 20°C, a low-boiling-point fluid is heated to vaporize. The vapor drives a turbine for power production, and is then cooled by cold seawater. This becomes a closed-cycle system, which operates 24/7 to produce reliable, clean power.
PLOTEC’s system comprises a cylindrical hull, a proprietary connection point, and a cold water pipe, all designed to withstand severe storm conditions. Others are not far behind in the technology, as UK-based Global OTEC Resources also received its first approval certificate to install its cold-water riser, which will transport seawater to a tank and back from an offshore OTEC system.
Weighing the advantages and disadvantages
The reason this technology has been taking forever to become a reality is that one must weigh the advantages against the disadvantages of OTEC systems. According to ScienceDirect.com, OTEC has the following advantages:
- Creating freshwater
- High energy potential (in principle)
- Zero greenhouse gas emissions
- Uninterrupted, clean base-load power
- High initial costs – the initial investment is not economical
- Complex engineering – the construction of large, efficient heat exchangers and cold water pipes is challenging
- Low efficiency at small gradients – efficiency is highly dependent on the correct temperature difference
- Geographic constraint – mostly efficient in tropical and subtropical regions
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