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New phase in Sofia project gets underway, also for Iv-Offshore & Energy Iv-Offshore & Energy

New phase in Sofia project gets underway, also for Iv-Offshore & Energy

For more than two years, a large team of Iv-Offshore & Energy engineers have been working on one of the most challenging projects to date: the HVDC (High-Voltage Direct Current) offshore converter platform for the Sofia Offshore Wind Farm. Sofia is one of the largest projects to date in RWE Renewables’ portfolio, with a generating capacity of 1.4 Gigawatts (GW). The design phase is coming to an end, but the project is not yet finished. On the contrary, in Indonesia, the construction of the platform is in full swing. 

For Iv-Offshore & Energy, the Sofia project is the largest project to date. In July 2020, Iv-Offshore & Energy signed the initial contract for the detailed design of the topside (the platform) and jacket (the foundation) with Sembcorp Marine Offshore Platforms Ltd (SMOP) in Singapore. Iv-Offshore & Energy also has another important role; the procurement of all auxiliary equipment for the platform.

It’s really just getting started now

GE Renewable Energy Grid Solutions (GE) is supplying the HVDC equipment. As SMOP’s engineering partner, Iv-Offshore & Energy is fully responsible for the platform engineering and system integration and is also supporting Sembcorp Marine on construction engineering queries. SMOP is currently constructing the platform on the Indonesian island of Batam, just off the coast of Singapore.

Given the important role of Iv-Offshore & Energy in this impressive offshore project, it comes as no surprise that following completion of the engineering works, Iv-Offshore & Energy will also support the construction to assist in answering any engineering questions from constructors and partners. In concrete terms, this means that from the new year, Iv employees will also be present on location at the SMOP site in Batam.

Restricted, but even more important
Project Manager Rogier Regenbogen is not yet looking back on one of the most exciting and challenging projects in the company’s history. “Our role is indeed not over yet. Actually, you could say that it’s just getting started. Our deliveries to the yard are almost complete, and since April 2022, Alex de Jong is our site representative in Batam. He will be positioned at the yard for two years on behalf of Iv-Offshore & Energy. He is our liaison between the client, construction team and other stakeholders on the SMOP yard and is also leading the Iv-Offshore & Energy site team. One of the activities of our site team is to monitor and support the yard to ensure that our delivered goods are preserved and handled properly.”

Iv-Offshore & Energy’s role, while somewhat decreased in terms of the amount of work, still remains important. After a successfully completed engineering phase, it is now crucial that all equipment and the platform are built and installed correctly and in accordance with our delivered design. Rogier Regenbogen: “That makes it a very nice and interesting project to execute. This is the first time we are working with SMOP, and the mutual expectations were not always aligned. Thus, another aspect that has to be managed.”

Qualitatively and quantitatively a lot
hat’s in store for Iv? In January 2023, additional engineers from Iv-Offshore & Energy will go to Indonesia. Then the installation work will commence and the last pieces of equipment, such as the pedestal crane and the last switchgear cabinets, will arrive at the SMOP yard. Iv-Offshore & Energy is responsible for transporting the goods to the yard in Batam. The transport from Europe to the Indonesian island takes around six weeks. “It was quite tense”, says Rogier, “to make sure all the paperwork was ready in time, the container ships booked, the containers stowed and above all: to ensure the goods arrive at the yard in the desired condition.”

To see the platform being built is really amazing

“It is especially exciting in terms of size and weight. This HVDC platform is huge. This is the largest platform (10,000 tonnes, ed.) we have designed to date. To actually see this being built is really amazing”, adds the project manager. 

Size of the platform
The HVDC platform, at the moment one of largest in the world to be commissioned, consists of six decks. In total, the platform will reach a height of approximately seventy five metres above sea level and is about forty metres wide and around one hundred metres long including the helideck. The topside will be installed on an eight-legged jacket, which will be placed on the seabed almost thirty metres below sea level. On the highest deck, the telecommunications mast of roughly twenty metres rises above the platform deck.

We are not afraid to take responsibility

Besides the sheer size of the converter platform, the complexity inside the platform was quite a challenge. Due to the large capacity of 1.4 Gigawatt, more space is simply needed to accommodate the larger HVDC and auxiliary installations. In our design, we also had to take into account the safe and easy accessibility of the installations for maintenance and inspections during operation of the platform. Not easy, but necessary to meet the high availability requirements, which required thinking beyond the boundaries.

The latter certainly applies to the cooling system. When converting alternating current to direct current, a lot of heat is generated, which must be dissipated. The installation is cooled with outside air and cooling water. In the past, we outsourced the HVAC installation. However, for the Sofia platform, Iv-Offshore & Energy designed the HVAC installation. Because we selected cooling water for the HVAC installation instead of air condensers, we could design a more compact cooling system. These are important details in a design that calls for creativity

It is especially exciting in term of size and weight

Energy for 1.2 million households
The platform design, which Iv-Offshore & Energy has been working on for the last two years, will increasingly become a reality in the coming months. A milestone and the start of a new phase at the same time. That Iv-Offshore & Energy is still involved is a good sign, Rogier believes. “We get a lot of responsibility and we are not afraid to accept it. In this phase, the construction yard asks a lot of questions, but because we understand the priorities, we can support our client in the best possible way.”

Following completion of the works in Batam in 2024, the Sofia HVDC platform will be shipped to the Dogger Bank to its final location, about two hundred kilometres north-east of the UK coast. The Offshore Converter Platform will be in full operation in 2026 and then be capable of powering approximately 1.2 million UK households. •

Would you like to know more about this project? Fedor will be pleased to tell you more. Contact him via 088 943 8339 or send Paul an email.