Tropical storm-proof OTEC system nears fabrication phase

Seven European partners are set to begin fabrication of an ocean thermal energy conversion (OTEC) platform said to be capable of surviving in tropical storm areas, destined for deployment offshore Spain.

Being developed under the EU-funded project PLOTEC, fabrication of the system is to begin this month and the platform is anticipated to be installed in the next few months at a testing site in the Canary Islands.

The structure of this platform consists of three main parts, including a cylindric hull, a cold-water riser pipe, and a gimbal connection point. 

The cold-water riser pipe is being manufactured by AGRU in Austria, while the cylindrical hull, the largest component of the installation, is currently being built at Hidramar Shipyard in Gran Canaria.

After the fabrication phase, expected to be completed in June, the 1:5 prototype will be assembled and installed at the Oceanic Platform of the Canary Islands (PLOCAN), approximately three kilometers from the coastline. 

Over its operational period, lasting around 12 months, the platform is set to endure the Atlantic Ocean’s conditions. Global OTEC said that computer simulations and a scaled tank test conducted in London last year confirmed the functionality of the proposed OTEC structure. 

The outcomes of the project are said to advance marine engineering design, new materials, and computational modeling, enhancing the accessibility of OTEC technology and materials available for other offshore floating energy and marine devices.

The PLOTEC project is dedicated to supporting the renewable energy transition in small island developing states (SIDS) that are known for severe weather conditions. 

According to Global OTEC, these countries rely on outdated diesel generators for electricity generation, lacking cleaner alternatives that are suitable for their geographical challenges. Such challenges encompass hurricanes, typhoons, severe storms, and other climate-related occurrences like El Niño.

The full-scale OTEC structure is also designed to be easily disconnected during extreme weather events and relocated to a secure harbor until the storm passes. 

Once the weather clears, it can swiftly be moved back and reconnected to continue electricity generation, leveraging the consistently warm surface seawater in the tropical ocean region regardless of climate conditions.

“This prototype will provide us with the perfect opportunity test our cylindrical hull and gimbal solutions in 20m equivalent waves and hone our offshore connection and disconnection procedure allowing us to maximise asset lifetime and availability even in storm prone regions”, said Sam Johnston, Lead Engineer at Global OTEC, one of the partners of the project.

The consortium behind the project consists of: Global OTEC (UK), Cleantech Engineering Limited (UK), WavEC Offshore Renewables (Portugal), The Oceanic Platform of the Canary Islands PLOCAN (Spain), Quality Culture (Italy), Agru Kunststofftechnik Gesellschaft m.b.H. (Austria) and University of Plymouth School of Engineering, Computing and Mathematics (UK). 

Global OTEC started testing the scaled design of the OTEC platform in May 2023.

In December 2022, the EU’s key funding program for research and innovation, Horizon Europe, and UK Research and Innovation (UKRI) awarded €3.5 million to the consortium for the design of the OTEC system.