The turbines of the future are floating on water. This is why the Adriatic is the perfect sea

Ancona – There is a lot of talk about renewable energy, especially about exploiting what the sea can offer with currents, waves and winds. But for the most industrialized technology, wind turbines, in Italy there is still little talk of construction sites, technologies and spaces for building foundations and support structures, fixed or floating, to be strategically placed in the most promising offshore areas from an energy point of view.
Engineer where is the technology in this regard?

“The technology for foundations that support offshore wind turbines is similar to that, already mature, of building foundations that support hydrocarbon extraction rigs, whether we are talking about grating structures or large columns that anchor to the bottom. From the sea whether we are talking about floating foundations. The difference lies Large in Quantity: While oil rigs are often one-of-a-kind projects, an offshore wind farm typically consists of 50-70 wind turbines; the foundations that support them are items easily over 1,000 tons each, going up to 3-4 000 tons for floating systems. This requires a design approach, which promotes simplification of construction and installation, redundancy, standardization of operations, mechanization, and secure implementation.”

For yards that can build such structures, what are the problems and what are the technologies for mass production?
“The first element is space. The most important component is the cost of means of anchoring at sea: these large ships can cost up to $500,000 per day, and projects cannot afford the waiting periods for these means: feeding them effectively means building, and ordering, up to 100 elements of foundations per year. This requires construction and storage space. And the space must be sufficient for that. It overlooks the sea and has an unusual lift off the ground. The entire production chain must be designed to adhere to the overall program, eliminating bottlenecks. Construction is different from oil structures, and becomes a process similar to that of an automobile assembly line. Pieces move, not men. Workstations repeat the same operations, mostly performed by robotic machines; The process is studied upstream and monitoring indicates compliance with the flow design scheme. Contingencies are analyzed in simulators, which redistribute production; Online quality checks. Therefore, the main feature is the manufacturing productivity mentality, compared to typical oil and gas facilities, which are often unique.”

What is the contribution of digitization?
“The production chain of the project includes the procurement of thousands of items worldwide, the prefabrication of sub-assemblies, their implementation by third parties, production lines designed to supply final assembly stations in a programmed manner, warehousing and transportation logistics at installation sites with fleets of subcontracted vehicles, The final installation program is subject to sea conditions … This series, reinforced by the number of elements to be provided, has various intersections and connections, which can significantly affect the outcome of the project.Only the control of this process can be digitized, starting from the design stage, where it is determined Each component is uniquely, then followed into the global program and controlled in its supply, production, quality and cost. The digital process should give the project manager, client and all operators involved an updated picture of the programme, cost and quality status, and allow appropriate solutions to be identified if corrections are needed.”

For wind energy, fixed or floating structures? What are the cons of each?
«Introduction: In the Mediterranean, regions of high winds (Marseille, Sardinia, Sicily …) mostly have depths that do not allow the use of fixed foundations anchored to the sea floor. The only Adriatic Sea with bottoms similar to those of Northern Europe is the Adriatic, but its winds are weak and not constant. In the future, in our seas we will necessarily have to move towards the floating foundations. These foundations are more complex from a design point of view, they are larger and therefore more expensive. But it does allow the installation of larger, next-generation turbines, of 12 megawatts each. They also allow the turbine to be installed on the berth, with transportation to the final position of the core turbine assembly, significantly reducing offshore installation costs and risks inherent in weather conditions. So in general the “floating” solution has attractive elements ».

Are there any promising prototypes?
“The technology is still immature. Across the world, prototypes have so far been built on small scales, even on a large scale, for comprehensive testing during their operational life. Countries like France, Korea, Norway, Scotland and Spain have decided to bet on these developments, but there are not even Now fully developed fields The proposed technologies are diverse, and there is still no reference standard. They range from items such as large life buoys to semi-submerged elements, to mostly submerged vertical elements. These foundations are produced with structures similar to those of ships, that is, with reinforced panels, This favors the shipyard experience. But the necessary spaces are not typical of shipyards, and the industry has to find a balance or ways to integrate the different experiences.”

Are there Italian shipyards working on this technology?
“I’m only abroad. In Italy, Saipem has 3 different concepts that it studied, designed and qualified in testbeds, which it tenders for international clients. Fincantieri also suggests itself, thanks to its experience in marine construction. The times of actual development in our seas are not instant: no Less than 6-7 years, when we have to go through a large-scale beta stage.”

What else is important to a contractor who already has oil and gas experience?
“The first is the separation of contracts between who must design, build and install the foundations and who supplies the production part and the turbine with its blades and the “shaft” that carries it. The universal object is structurally unique, but the design is divided between the two themes, also due to protection defined by the turbine manufacturer. This involves a complex and lengthy process of finding a design solution, which is not always improved. Another critical element for a main contractor operating in the oil and gas market is an unusual level of contractual risk: wind power projects are mostly allocated by governments to concessionaires based on kilowatt prices already set at the tender stage. They are mostly funded projects, thus with very little margin to accommodate unexpected events. Such unforeseen events, of all kinds, are downloaded entirely to the final main contractor. This element, along with the “repetition” of elements, can lead to the glorification of an element that has been underestimated or incorrectly appreciated, with very serious consequences for the overall project outcome. Many oil and gas conductors burned on their first projects and decided to abandon this market.”

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