Page 44: of Offshore Engineer Magazine (Nov/Dec 2024)

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FLOATING WIND SUBSEA CABLING

For our star configuration, we never have more than one in a single line, so the entire field can be standardized down to one size, typically 95 or 150 square millimeters.

– Mike Birch, Product Manager for Offshore Power Systems at

Baker Hughes

The simplicity of the design belies its importance, be- foating wind – the margins are too low for renewables. We cause with multiple turbines connected directly to a collec- need to have structured building blocks – connectors, col- tor hub the problems associated with daisy-chaining cables lector hubs, turbines – that’s the only way to get economies are removed. Currently used for fxed offshore wind, if a of scale that can bring down the levelized cost of energy.” cable fails at any point in the daisy-chain, the power from Product qualifcation for the new connectors is expect- an entire train may be lost, but the collector hub enables a ed to be completed next year, in time for the dramatic star confguration where each turbine is connected to the foating wind market growth that Birch anticipates from collector hub independently from other turbines. 2027. “The future is promising, with projections estimat- “If you look at the star confguration, it’s obviously got ing around 270GW of installed foating wind capacity benefts with availability because you can isolate an in- by 2050. At an average of 15MW per turbine, achieving dividual turbine or group of turbines, depending on the this will require more than 700 foating wind turbines de- confguration. The second part of that is because you don’t ployed annually for the next 25 years.” have multiple turbines in series, you can reduce the size of Birch foresees a range of possible confgurations being the cables and standardize on one size.” used. The Baker Hughes subsea design can take turbine

In a daisy chain, cable diameters could start at 95 square energy to an onshore grid or additionally to offshore in- millimeters of copper, then increase to 300 and then, say, stallations or power-to-x platforms. It can also be used for 1,000, as the power from each turbine is aggregated along tidal arrays, an opportunity that Birch considers will be the array. suitable for some applications, such as providing power to “For our star confguration, we never have more than islands. For long-distance energy transport to shore, the one in a single line, so the entire feld can be standardized system can also include midpoint reactors that re-establish down to one size, typically 95 or 150 square millimeters. the integrity of the transmission through the export cable

There’s an enormous difference in cost between 1,000 so that the current limit of around 100-150 kilometers square millimeters and 95 square millimeters. That’s the from substation to shore can be extended.

CAPEX beneft, but there’s also an OPEX perspective. It There’s more connector development expected in the means you only need to keep one cable size in stock.” future. “We’re looking at 66kV today, but 20MW tur-

This sort of standardization is crucial for the burgeon- bines are on the way that will require 132kV. Some of ing foating wind market’s viability, says Birch. “Unlike the these felds just won’t be economically viable without oil and gas industry, we cannot have bespoke systems in these very large turbines.” 44 OFFSHORE ENGINEER OEDIGITAL.COM