Floating wind farm gearbox, generator, and blade replacement – a prospectively high-price problem for the emerging sector as its works to hone its project economics – could be “meaningfully improved” using a novel concept that fits a lightweight crane on a semisubmersible turbine platform during operations and maintenance (O&M), according to the head of Fred Olsen’s innovation arm, Fred Olsen 1848.
The company’s Floating Maintenance Solution (FMS) concept, which moved ahead today (Tuesday) with signing of a memorandum of understanding with crane specialist Huisman, would involve an offshore supply vessel ferrying out the 150-tonne telescopic crane, which features a ‘foldable’ knuckle boom, and attaching it via a “quick connection” interface ring mounted atop one of a floating foundation’s columns.
The concept, engineered for turbines with nameplates up to 15MW, would remove the need to tow a floating wind unit to shore for maintenance or repair or to carry-out ‘dynamic’ lifts of major components between an installation vessel and the floating turbine at sea.
“We've looked into all the present O&M solutions that are out there currently, and the baseline is still to tow based on towing the foundations to shore and exchanging the major components. And that [approach] will, of course, lead to excessive downtime and loss of power production [for from a floating wind development]. And if you if you calculate that the total time – and timing of the ‘weather windows’ – to perform these operations, it will be a huge cost. We felt there must be a better way,” Sofie Olsen Jebsen, CEO of Fred Olsen 1848, told Recharge.
“Much as floating wind requires a lot of innovation, there are areas [such as O&M] where we believe incremental solutions are better. This gives greater certainty about the reliability. This is why we have developed this solution that contains a crane that ‘looks like’ a crane,” she said.
“By lifting putting the crane on to the floating foundation, you have [it] operating in the same relative motions as the foundation. That provides a great advantage in operations. This helps take away a large part of the risk [of such a maintenance solution], which is the dynamic lift between two floating units.
“We have been working with this solution for some time and believe it will be a really good solution for floating wind O&M, as it is,” Jebsen said.
Detailing of the projected cost savings from the concept are “in the process of being calculated”, she said, adding: “It is apparent that this design will lead to meaningful improvements in [reduction of] downtime” and so boost production revenue as well as cutting overall operating expenditure.”
Huisman CEO David Roodenburg, said the two companies had “a joint ambition to accelerate the maturity of the floating wind market”.
“The combination of Fred Olsen 1848’s dedication to innovate and [its parent group] companies’ extensive experience in O&M operations, together with Huisman’s capabilities in designing and building cranes to specific client needs has led to this unique crane setup,” he stated.
The crane design to be used has an all-electric drive system, affording it “high positioning accuracy, low energy use, reduced maintenance, and high reliability” and a dedicated energy storage system that will power it from the turbine’s auxiliary circuits.
The FMS has “already attracted the interest of several large floating wind developers” Jebsen noted, though she was not able to disclose any by name “at the moment”, as it addresses a “big unsolved issue” in floating wind power project development.
The next milestone for the concept, according to the two companies, is a detailed project front-end engineering and design study, with an eye on “bringing the solution into operation before the end of this decade”.
Jebsen continue: “Innovation and collaboration are key to realise commercial development of floating offshore wind. We have worked to solve the maintenance challenge in floating wind by building on the decade-long experience with O&M operations from our sister-companies Fred Olsen Windcarrier and Global Wind Service.
“Component exchange solutions are too costly both in terms of assets required, downtime of the turbine and available weather windows. We believe the FMS will be a game-changer… and can enable the industrialisation of floating wind.”
The FMS is the latest in a portfolio of technology solutions that have been launched by Fred Olsen 1848 since it started-up last year. The “innovation company”, named after the year in which its Oslo-headquartered parent started up its shipping business, has six new concepts it plans to commercialise, with the first three dedicated to floating wind farm construction and operation. Along with the FMS, this includes its ‘mobile port solution’ – a concept that marries a jack-up installation vessel, a barge and feeder vessels to create an offshore assembly facility – and the Brunel floating wind unit design.
“This solution very much fits into the philosophy of Fred Olsen 1848 in that it solves a key industry challenge… and in a way that can help bring down the LCOE [levellised cost of energy] in floating wind markets around the world,” said Jebsen.
