Stiftung Offshore Windenergie

New study: Significant acceleration and cost reduction potential for offshore grid connections possible, integration into the onshore grid feasible.

Berlin, June 29, 2016. A new study shows significant acceleration and cost reduction potential for offshore HVDC grid connections and recommends improved grid utilization for short-term elimination of network bottlenecks on land. A deceleration of offshore network connections would not be appropriate, according to the study.

“Offshore wind energy has established itself successfully in the energy mix of the Energiewende. Beyond 2020, the offshore wind energy industry will continue to require annual implementation of a grid connection system in order to fulfil the ongoing expansion goals declared by the German government, starting with the NOR-3-3 connection in 2021. This absolutely must be confirmed by the Bundesrat and the Bundestag in the 2016 Renewable Energy Act, explain the lead partners of the study.

The German Offshore Wind Energy Foundation and the trade association WVW commissioned the study with the support of the associations AGOW, OFW, OWIA, VDMA Power Systems and WAB as well as the companies 8.2 Consulting AG, ABB AG, ADWEN GmbH, ENOVA Energieanlagen GmbH, GE Energy Germany, Nordwest Assekuranzmakler GmbH & Co. KG, PNE WIND AG, SIEMENS AG, Strabag OW EVS GmbH, WindMW GmbH and wpd offshore solutions GmbH. The study was carried out by Fichtner GmbH and the law firm GGSC.

According to the analysis, an acceleration potential of 8 to 14 months is possible for the tendering and awarding phase for offshore HVDC grid connection systems, as well as for the project implementation phase. For the planning and approval phase, an acceleration potential of 6 to 9 months has been identified. For each of these phases, this results in a time savings of 10-25 percent . The study also identifies substantial cost reduction potential. Just by introducing technical innovations in connection concepts, cost reductions of up to 30 percent are possible according to the study. “Acceleration and cost reductions are essential not only for offshore grid connections, but also in the case of networks on land,” the lead partners of the study write. “For the successful implementation of the Energiewende, a rapid grid expansion at sea and on shore is of crucial importance.”

Furthermore, the study's authors believe that Germany’s onshore grid constraints – which currently hamper the transmission of offshore wind energy to shore in critical situations – can be overcome in the short term by means of improved network utilization using “dynamic real-time processes” until sufficient capacity is available. In addition, increased use of hybrid lines, for example, could be useful. Above all, however, the current grid must quickly make use of the technical options available today (Online-DSA, Dynamic Security Assessment). 

Technical innovations, standardization and optimized planning can save time and money

The study analyses acceleration and cost reduction potential in offshore HVDC grid connections starting from the planning and approval phase through the tendering and awarding phase, up to the implementation phase. In the approval process, for example, time can be saved with standardized application procedures; on the technical side, cost reductions of up to 30 percent are possible thanks to innovative HVDC grid connection concepts. These include concepts for directly connecting wind turbines to converters and using decentralised, smaller converter units. In order to realise technical innovations, special areas for demonstration and pilot projects should be identified. For the implementation of these technological innovations, it is of central importance that the technology and connection concepts specified in the Federal Offshore Plan can be implemented in a more flexible way. In addition, the rigid system performance and operating voltage limitations need to be overcome. For the tendering and awarding phase, more competition and transparency also translate to cost reduction and acceleration potential.

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