TenneT develops first 2GW offshore grid connection with suppliers

Alongside the eight 0.7 Gigawatts (GW) AC grid connections already planned, two 2 GW offshore grid connections will be built in the IJmuiden Ver wind energy area. Such a grid connection is currently not existing. This requires a new platform design and a high voltage direct current (HVDC) transmission system that allows increased power transfer.

TenneT has entered into a so-called innovation partnership* with its suppliers to ensure that this technically advanced and innovative requirement will connect seamlessly with what they can develop and manufacture.

Given the combination of the large distance to the coast and the size of the IJmuiden Ver wind energy area, a 2 GW direct current (HVDC) solution, based on 525 kilovolts, appears to offer most economical  advantages. It requires only one cable system per 2 GW, limiting the impact on the environment and the surroundings.

To realise such an innovative direct current system, TenneT launched the design phase with five HVDC suppliers on the basis of an innovation partnership: ABB Power Grids, GE Renewable Energy’s Grid Solutions  (Netherlands), Consortium Global Energy Interconnection Research Institute Co. Ltd. (GEIRI) & C-EPRI Electric Power Engineering Co. Ltd. (C-EPRI) (China), Siemens (Germany), and Xian Electric Engineering Co., Ltd (China). These suppliers will develop this innovative 2 GW 525 kV HVDC solution based on criteria set by TenneT. They will provide specific information on this to Iv-Offshore&Energy b.v., which is carrying out the Front-End Engineering Design (FEED) study on behalf of TenneT. On this basis, a standardised platform design will be developed for all HVDC solutions.

Standardised platform

The information from the joint R&D innovation phase will be used for the final design of the platform. TenneT uses this standardised design for the contracting of several 2 GW grid connections (including IJmuiden Ver Alpha and Beta). This contributes to reducing costs for the offshore grid.

TenneT thus fulfils its responsibility as grid operator of the offshore grid, by stimulating innovative solutions that contribute to rolling out a cost-efficient and future-proof offshore grid infrastructure.

Experience in Germany

The move to connections with a 2 GW capacity is made possible through TenneT’s extensive experience with offshore HVDC grid connections in Germany, as well as with interconnectors. TenneT also uses the high-voltage 525 kV level for the new international offshore connection between Germany and Norway, NordLink. TenneT will realise at least four 2 GW offshore grid connection projects in Germany from 2029. The results of the FEED study and the R&D phase of the innovation partnership will also provide emphatic input for this, because TenneT strives to standardise the systems wherever possible.

Scale of IJmuiden Ver projects

IJmuiden Ver will have wind farms with a total capacity of 4 GW. With the new 2 GW connection concept, TenneT wants to make optimal use of the area’s scale. This is in line with the offshore wind industry’s desire for larger wind farms. TenneT is building two grid connections, each of 2 GW, for this purpose: Net op zee IJmuiden Ver Alpha, and Net op zee IJmuiden Beta. Preparations and procedures for these projects began in 2019, and Net op Zee IJmuiden Ver Alpha and Net op Zee IJmuiden Ver Beta are scheduled to go into operation in 2030.

_{*An innovation partnership is a tendering procedure in which TenneT, as contracting authority, can start a development process together with suppliers and then proceed to purchase the solution that is not yet available on the market.}