“We are pursuing the concept of a meshed direct current grid at sea and on land.“

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North Sea by 2030 and as much as 300 gigawatts by 2050. How can this task be tackled?

The Euro­pean ener­gy transition—the com­plete con­ver­sion of our fos­sil ener­gy sys­tem to one that is essen­tial­ly based on renew­able energies—is one of the great­est chal­lenges of our time. This can only suc­ceed if we work togeth­er deci­sive­ly and across nation­al bor­ders. To be able to meet ris­ing demand while becom­ing cli­mate neu­tral, the EU mem­ber states must rapid­ly and com­pre­hen­sive­ly expand renew­able ener­gies and trans­mis­sion grids.

If we look at Cen­tral Europe, wind and solar ener­gy will be the main sources avail­able to us in the future. Off­shore wind ener­gy will play a cen­tral role here and the North Sea will devel­op into a pow­er­house for north­west Europe. Com­pa­nies from the North Sea states of the Nether­lands, Den­mark and Ger­many there­fore joined forces in 2017 and launched the North Sea Wind Pow­er Hub as one of the Projects of Com­mon Inter­est.

The focus of this project is on three ideas. First, the immense poten­tial of the North Sea is to be tapped with cross-bor­der con­nec­tions via an ener­gy hub at sea. Sec­ond, the com­bi­na­tion of wind farm con­nec­tion lines and inter­con­nec­tors will cre­ate a cost-effi­cient and resilient transna­tion­al grid struc­ture that con­nects dif­fer­ent weath­er sys­tems and helps to sta­bi­lize the volatile sup­ply of renew­able ener­gies. And, third, the inte­gra­tion of dif­fer­ent ener­gy sec­tors and ener­gy sources cre­ates the best con­di­tions for the pro­duc­tion of hydro­gen, thus sup­port­ing the decar­boniza­tion of indus­try.

As Europe’s lead­ing off­shore trans­mis­sion sys­tem oper­a­tor, Ten­neT is already mas­sive­ly dri­ving for­ward the expan­sion and devel­op­ment of new tech­ni­cal stan­dards. We cur­rent­ly oper­ate off­shore grid con­nec­tion sys­tems with a total capac­i­ty of around 11.5 gigawatts (GW). By 2031, we will expand this capac­i­ty to a good 40 GW and thus pro­vide a third of the Euro­pean tar­get of 120 GW for 2030.

How can the massive expansion of wind energy generation in the North Sea be accelerated?

One answer to this is the North Sea Wind Pow­er Hub. Instead of indi­vid­ual nation­al point-to-point con­nec­tions, we are inves­ti­gat­ing how the large wind poten­tial in the North Sea can be joint­ly devel­oped and dis­trib­uted by the Euro­pean coun­tries. As a result, the coun­tries involved will achieve a sig­nif­i­cant accel­er­a­tion in the expan­sion of off­shore wind ener­gy as a basis for achiev­ing the tar­get of cli­mate neu­tral­i­ty by 2045.

A sec­ond answer is our 2 GW program—our new tech­ni­cal stan­dard which will accel­er­ate grid expan­sion in the North Sea and fur­ther dri­ve the Euro­pean ener­gy tran­si­tion. It will con­serve resources and reduce envi­ron­men­tal impact—with more than twice the pow­er com­pared to pre­vi­ous sys­tems. It involves a stan­dard­ized 2 GW high-volt­age direct cur­rent (HVDC) trans­mis­sion plat­form con­cept and a new 525 kV cable sys­tem.

Both will increase the trans­mis­sion capac­i­ty while at the same time reduc­ing the impact on the envi­ron­ment. By 2031, Ten­neT will build at least 14 of these 2 GW off­shore grid con­nec­tion sys­tems in the Ger­man-Dutch North Sea. Togeth­er, the projects will sup­ply up to 35 mil­lion Euro­pean house­holds with green wind ener­gy from the North Sea. The 2 GW stan­dard is tech­ni­cal­ly the cen­tral build­ing block for a mod­u­lar North Sea Wind­pow­er Hub con­cept.

What concepts is TenneT pursuing in the North Sea?

We are pur­su­ing the con­cept of a meshed direct cur­rent grid at sea and on land. In order to tap into the immense poten­tial in the North Sea, wind farms need to be net­worked across nation­al bor­ders with dis­tri­b­u­tion hubs and high-per­for­mance grid infra­struc­ture. We are cur­rent­ly work­ing on net­work­ing off­shore grid con­nec­tion sys­tems on the high seas so that pow­er can be bun­dled and dis­trib­uted inter­na­tion­al­ly in a sen­si­ble way. In Ger­many, for exam­ple, the grid con­nec­tion points on land are suit­able loca­tions for direct­ly sup­ply­ing impor­tant indus­tries with green ener­gy. In terms of sec­tor cou­pling, this cre­ates the best con­di­tions for the pro­duc­tion and inte­gra­tion of hydro­gen to decar­bonize indus­try.

Anoth­er new fea­ture is that direct cur­rent lines on land are being designed as a meshed sys­tem: At select­ed grid con­nec­tion points on land, the direct cur­rent lines from the sea are to be direct­ly net­worked with the fur­ther trans­mit­ting direct cur­rent lines on land in so-called mul­ti-ter­mi­nal hubs. This will make the sys­tem even more robust, pow­er­ful, and cost-effi­cient and will also sig­nif­i­cant­ly min­i­mize land con­sump­tion and envi­ron­men­tal impact which are impor­tant fac­tors for accep­tance.

In your opinion, are artificial energy islands as a distribution hub for offshore wind energy a solution?

Plan­ning for off­shore wind farm net­works is still at an ear­ly stage and depends heav­i­ly on local con­di­tions, par­tic­u­lar­ly the depth of the water. In prin­ci­ple, very dif­fer­ent mod­els can be used—various types of plat­form struc­tures or even islands.

Much more impor­tant in the dis­cus­sion is the nec­es­sary tech­ni­cal stan­dard­iza­tion of con­vert­er plat­forms and off­shore con­nec­tion sys­tems. Only with a cross-provider and cross-oper­a­tor tech­ni­cal stan­dard can net­work­ing be real­ized, and the sys­tem become flex­i­ble and effi­cient.

What significance will the production of green hydrogen have in the context of wind power expansion?

Mol­e­cules are an indis­pens­able build­ing block for the ener­gy tran­si­tion and in the long term, togeth­er with elec­tric­i­ty, they form the ener­gy basis for our indus­try. In short: we can’t do with­out mol­e­cules. We will con­tin­ue to import most of our hydro­gen from oth­er parts of the world in the future but elec­trol­y­sis in the Ger­man North Sea is cur­rent­ly being inten­sive­ly inves­ti­gat­ed.

As a trans­mis­sion sys­tem oper­a­tor, the impor­tant fac­tor for us in the end is that electrolyzers—including those in the North Sea—must be locat­ed in a way that serves the grid and there­fore does not gen­er­ate any fur­ther grid bot­tle­necks. This means that wher­ev­er we need ener­gy in the form of elec­tric­i­ty, it is more effi­cient not to take the detour via hydro­gen, but to trans­port the elec­tric­i­ty from the place of gen­er­a­tion to the con­sumers via lines. This is because a lot of ener­gy is lost dur­ing the dou­ble con­ver­sion of elec­tric­i­ty to hydro­gen and back again. How­ev­er, we need green hydro­gen in many areas, for exam­ple to decar­bonize indus­try or for gas-fired pow­er plants.

In a sys­tem based on volatile ener­gy sources such as solar and wind, we urgent­ly need addi­tion­al secured elec­tric­i­ty output—i.e. a reli­able backup—and hydro­gen-capa­ble gas-fired pow­er plants will play a cen­tral role in this regard. This is also envis­aged in the Ger­man government’s pow­er plant strat­e­gy with its real­iza­tion that gas-fired pow­er plants must be able to step in flex­i­bly if renew­ables tem­porar­i­ly do not sup­ply enough elec­tric­i­ty. This is why hydro­gen is of out­stand­ing impor­tance for our future ener­gy sup­ply and sys­tem secu­ri­ty.

Which operating resources and services are becoming more important in the context of these major tasks?

Tack­ling the Euro­pean ener­gy tran­si­tion from the North Sea is a promis­ing plan—and an enor­mous chal­lenge. More and more wind farms and off­shore grid con­nec­tion sys­tems need to be built in ever short­er time­frames. At the same time, frag­ile sup­ply chains and sharply ris­ing mate­r­i­al costs on the glob­al mar­ket, for exam­ple for raw mate­ri­als, are mak­ing it increas­ing­ly dif­fi­cult to imple­ment this project in a time­ly and cost-effi­cient man­ner.

With our inno­v­a­tive 2 GW stan­dard, we have devel­oped a con­trac­tu­al, admin­is­tra­tive, and tech­no­log­i­cal blue­print for future off­shore grid con­nec­tion sys­tems. We have thus cre­at­ed a strong foun­da­tion for mak­ing green wind ener­gy from the North Sea scal­able and even more cost-effi­cient in the future. The use of FIDIC stan­dard con­tracts in our projects also con­tributes to this since FIDIC is rec­og­nized world­wide, is used through­out the indus­try and facil­i­tates the imple­men­ta­tion of our 2 GW stan­dards.

Nev­er­the­less, off­shore expan­sion rep­re­sents an enor­mous chal­lenge. More and more sys­tems need to be pro­duced, installed and com­mis­sioned in ever short­er time peri­ods. This will only be pos­si­ble in a joint effort. We have there­fore decid­ed to pub­lish large-scale ten­ders for our HVDC systems/platforms and the cable sys­tems for a whole range of grid con­nec­tion sys­tems instead of indi­vid­ual ten­ders in order to offer our sup­ply chain a reli­able long-term per­spec­tive. With our new approach, we are bring­ing togeth­er key mar­ket play­ers at an ear­ly stage, pool­ing exper­tise, and cre­at­ing syn­er­gies. In this way, we increase mar­ket capac­i­ties in good time and pro­mote com­mit­ment and coop­er­a­tion. Our part­ner­ship approach is a prime exam­ple of a long-term com­mit­ment to sus­tain­able and rapid grid expan­sion in the North Sea.

The even stronger focus on part­ner­ship goes hand in hand with a fun­da­men­tal change in val­ues. Sup­pli­ers and cus­tomers are becom­ing even clos­er part­ners with shared goals, shared chal­lenges, and shared respon­si­bil­i­ties. Only togeth­er as a team will we be able to increase the pace of net­work expan­sion and mas­ter this his­toric chal­lenge.