The foundation for the world´s largest wind farm

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In the North Sea, some 120 kilo­me­ters off the British coast, Hornsea 3 – one of the world’s largest off­shore wind farms – is set to be com­plet­ed by 2027. Con­struct­ed by the Dan­ish ener­gy com­pa­ny Ørst­ed, it is expect­ed to sup­ply over three mil­lion house­holds in the UK with elec­tric­i­ty upon com­ple­tion, with a capac­i­ty of 2.85 gigawatts. To this end, Ørst­ed is installing sev­er­al hun­dred wind tur­bines across an area of near­ly 700 square kilo­me­ters on the high seas. To with­stand waves and storms, they are anchored to the seabed with mas­sive steel piles, known as monopiles.

The com­pa­ny SeAH Wind spe­cial­izes in the con­struc­tion of these foun­da­tions. Extra for the Hornsea 3 project, the man­u­fac­tur­er has built the world’s largest monopile fac­to­ry to date in Tee­side, in the north­east of Eng­land. The site is thus one of the most impor­tant among sev­er­al sup­pli­ers for Hornsea 3. To put the dimen­sions into per­spec­tive: Some of the monopiles are over 100 meters long and weigh more than 2,000 tons. Pro­duc­tion is designed so that SeAH Wind can man­u­fac­ture up to 200 of these giants per year.

Target: Stable plant network

Ear­ly in the factory’s plan­ning phase, SES Engi­neer­ing – the gen­er­al con­trac­tor for build­ing ser­vices, and a mem­ber of the Wates Group – com­mis­sioned the firm Enspec Pow­er to design a robust plant pow­er dis­tri­b­u­tion sys­tem. This is because volt­age qual­i­ty is crit­i­cal for reli­able oper­a­tion, ensur­ing the fac­to­ry meets grid con­nec­tion require­ments and pre­vent­ing dam­age to the machin­ery.

For Tony Jef­fer­son, who led the project at Enspec Pow­er, this was no easy task: “When we received the con­tract in 2024, the fac­to­ry exist­ed only as a blue­print. So our work relied on pre­dic­tive sys­tem mod­el­ling rather than phys­i­cal mea­sure­ments.” To get a rough idea of the expect­ed chal­lenges regard­ing pow­er qual­i­ty, Enspec Pow­er there­fore first cre­at­ed a vir­tu­al mod­el of the fac­to­ry in col­lab­o­ra­tion with SES Engi­neer­ing.

Tested on the model

“We were able to esti­mate that some of the equip­ment would cause sig­nif­i­cant reac­tive pow­er demand – that is, elec­tri­cal ener­gy that isn’t con­vert­ed into use­ful work and strains the sys­tem,” reports Jef­fer­son. But that isn’t the only prob­lem: “We know from expe­ri­ence that har­mon­ics always occur. It’s a very dynam­ic process that sim­ply requires a lot of pow­er,” says Jef­fer­son.

And here’s how the process works: First, a cut­ting sys­tem cuts sol­id steel plates into large rec­tan­gles. Then rollers bend the steel strips into a cir­cu­lar shape, which weld­ing machines weld togeth­er at the ends. This is where things get crit­i­cal: “The weld­ing machines cause the largest share of the har­mon­ics; but oth­er machines, such as the rollers, also gen­er­ate har­mon­ics. This is due to their fre­quen­cy con­vert­ers,” says Jef­fer­son.

These ensure that SeAH Wind can flex­i­bly adapt the speed of the motors of the high­ly auto­mat­ed sys­tems to pro­duc­tion require­ments. While this makes the use of the machines effi­cient, it also gen­er­ates har­mon­ics. If these aren’t fil­tered out, they can inter­fere with upstream and down­stream sys­tems. In the worst case, they can even cause dam­age.

Better safe than sorry

“Because the oper­a­tional load­ing pro­file would evolve over time, the solu­tion need­ed to be scal­able and flex­i­ble enough to adapt along­side pro­duc­tion require­ments.” says Jef­fer­son. He didn’t have to think long about where to turn for help because Enspec Pow­er has been work­ing with Rein­hausen for about sev­en years. So he quick­ly picked up the phone to con­sult with Kim Urbanke and Hen­ning Tis­ch­er from the Pow­er Qual­i­ty Con­vert­ers busi­ness unit.

An idea was quick­ly born: mod­u­lar con­trol cab­i­nets with pow­er elec­tron­ics from Rein­hausen. A total of 29 active fil­ters based on Rein­hausen tech­nol­o­gy com­pen­sate for har­mon­ics in real time. In addi­tion, there are 26 reac­tive pow­er com­pen­sa­tion sys­tems. This ensures pow­er qual­i­ty even under high loads. Jef­fer­son says: “In my expe­ri­ence, MR man­u­fac­tures the world’s best fil­ters for indus­try. They respond dynam­i­cal­ly to chang­ing loads and can be pre­cise­ly con­trolled.”

Turnkey solution

Thanks to the mod­u­lar prin­ci­ple, Enspec Pow­er can deliv­er the pow­er required at each con­nec­tion point – and eas­i­ly and safe­ly expand the sys­tem as need­ed. Enspec Pow­er not only designed the solu­tion but also man­u­fac­tured it at its pro­duc­tion site in Wash­ing­ton and sub­se­quent­ly installed it, in col­lab­o­ra­tion with SES Engi­neer­ing, at the XXL fac­to­ry.  For the region, the fac­to­ry serves as a spring­board for becom­ing an indus­tri­al hub for wind pow­er. Jef­fer­son is proud of the project: “This fac­to­ry is an exam­ple of how the ener­gy tran­si­tion is trans­form­ing indus­tri­al regions and cat­alyz­ing eco­nom­ic growth.”