Following the news of the completion of the installation of the 60 monopiles and transition pieces at E.ON’s Arkona Becken Südost windfarm project ahead of schedule, Cathie now inform that they have performed a study which enabled the reduction of noise in the water column created by monopile driving.
The study was performed for E.On by leading offshore geoscience and geotechnical engineering consultancy during the planning of the monopile installation operations. It enabled the development of a hammer energy profile which allowed monopiles to be driven at reduced energy levels while still achieving required target penetration depth within the driving pile time restrictions applicable in Germany. This successfully contributed to the reduction of the noise in the water column produced by the pile driving process, versus a more standard hammer energy profile.
Rui Silvano, one of Cathie’s Senior Engineers worked closely with E.ON on the project: “We obviously understand the cost pressures facing our clients in the offshore wind industry. Because Noise Mitigation is a key industry issue with very high associated costs this seems an obvious area to focus.
Although reducing the energy will no doubt help reducing the resultant noise in the water column, the challenge was in achieving a fine balance: We had to ensure the recommended energy profile was optimised to drive the monopiles to the required depth within the 180 minute time restriction required by the BSH in Germany while verifying that the monopile fatigue during driving remained low despite the increased number of hammer blows associated with a reduced hammer energy.
We’re delighted that now the installation is complete, we can now confirm that our study successfully contributed to reducing the noise in the water column created by monopile driving.”