Page 14: of Marine Technology Magazine (January 2022)

SUBSEA PROCESSING neering company Linxon and its parent companies Hitachi size to the Hutton TLP.”

ABB Power Grids and SNC-Lavalin/Atkins partnered to For an HDVC solution, Jones said you’d be looking at a “make ? oating substations for offshore wind a reality”. Dae- 66m x 70m footprint, on a four-column semisubmersible woo Shipbuilding & Marine Engineering and Korea Electric with a stressed-skin topsides, for strength and stiffness. In

Power Technology Company have also said they’re working fact, this is just the type of structure – in the form of drill- on offerings for the ? oating offshore wind substation market ing rigs or ? oating production units – that’s been laid up in for both deep and shallow waters. the downturn and could potentially be converted, subject to

Petrofac has been doing some detailed work on ? oating many caveats, not least related to fatigue, but it’s feasible, substation concepts. As projects scale up from 250MW pi- says Jones. lot scale projects to GW-scale farms, and from high voltage HVAC substations have a smaller footprint and are light-

AC to DC transformers, Jones says there will be different er weight than HVDC for the same capacity, which makes design requirements. For pilot projects, HVAC will be used. semisubmersibles less attractive; they’re only really optimal

As projects ramp up to gigawatt scale far from shore, they once the structure has a topside footprint above 50m by 50m, will need HVDC substations. For HVDC projects, ? oaters says Jones. will be larger, because DC takes up more space, due to more For GW-scale projects Petrofac came up with a deep-draft equipment and the requirement to keep the high voltage DC semisubmersible design, giving low motion, but retaining equipment adequately separated. They are also sensitive to shallow draught for transportation and maintenance, with a accelerations, so a semisubmersible is a good solution, says minimal braced topside structure. “The design has the added

Jones. “A deep spar could be a problem when you need that advantage that the cable outlet is well below the water surface, topside mass and footprint. There are other options, such as giving reduced cable fatigue,” he says. The ? rst projects with a tension leg platform (TLP), but it would need a similar hull substations may have a capacity closer to 250MW, connect-

A substation concept under the Opti? ot project between Ideol,

ABB and STX.

Photo courtesy Ideol 14 January/February 2022

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