The halfway point in the construction of the storm-resistant OTEC prototype has been reached

Production began in March, and once completed, the cylindrical hull, complete with cold water riser pipe and gimbal connection point, will be assembled in the Atlantic Ocean for testing. This structure is being developed by PLOTEC, an EU-funded pan-European consortium composed of seven companies.

The shipyard’s latest achievements include the completion of the first level of the platform, which was achieved by plasma cutting of over 660 steel sheets ranging in thickness from 6 mm to 65 mm. The assembly of the entire structure progresses quickly. Each plate is meticulously prepared for welding, mounted on the keel to check fit, then welded to its final position, with all welds rigorously tested for defects.

OTEC Global Chief Engineer Sam Johnston explains that this phase of the project is particularly time-consuming due to the complexity of the keel, which consists of multiple plates requiring multiple welding passes. This meticulous process ensures structural integrity while minimizing the risk of warping due to the heat generated during welding.

Additionally, mooring eyes are now machined prior to welding to ensure a solid connection to the keel. “Once the keel plate is complete, we expect the rate of progress to increase as many of the more complex welds are completed, allowing us to begin installing the cylindrical skins on the keel,” emphasizes Johnston.

The project aims to accelerate the transition to renewable energy in small island developing states (SIDS), which are vulnerable to severe weather conditions. This will be achieved by enhancing OTEC technology with an offshore platform specifically designed to withstand intense tropical storms, hurricanes and cyclones.

Largely dependent on outdated diesel generators, SIDS lack clean and geographically appropriate electricity generation alternatives. Considering the ocean as the richest natural resource, OTEC proves to be a suitable power generation solution, especially when it is adapted to withstand the harsh weather conditions they face.

The 1:5 scale PLOTEC prototype will be installed for testing on the Canary Islands Ocean Platform (PLOCAN), approximately three kilometers from the coast. Throughout its operational life, the platform will be exposed to Atlantic Ocean conditions, which will enable extensive analysis of its strength, materials and design.

Previous computer simulations and tank tests conducted last year in London have already confirmed the expected functionality of the structure. In addition to increasing the viability of OTEC on tropical islands in storm-prone areas, project findings will advance marine engineering design, novel materials development, computational modeling, and the design of other offshore floating energy and maritime facilities.