Abstract
Sunrise Wind has proposed to construct and operate a 924 megawatts (MW) wind energy facility located on the Outer Continental Shelf (OCS) in the designated Bureau of Ocean Energy Management (BOEM) Renewable Energy Lease Area OCS-A 0487 (Lease Area). The SRWF will consist of installation of 84 wind turbine generators (WTGs) connected by a network of Inter-Array Cables and a single Offshore Converter Station (OCS-DC). The WTGs and OCS-DC will be sited in a uniform east west/north-south grid with 1.15 mi (1 nm, 1.8 km) by 1.15 mi (1 nm, 1.8 km) spacing that aligns layouts proposed for other projects in the Rhode Island/Massachusetts Wind Energy Area (MA WEA). This Plan includes mitigation measures associated with the sequential installation of the OCS-DC jacket foundation (four pin piles/day), as well as concurrent installation (proximal assumptions4) of WTG MP foundations (one vessel installing two MPs/day)) and OCS-DC jacket foundation (one vessel installing four pin piles/day). Concurrent installation (distal assumptions5) of WTG MP foundations (one vessel installing two MPs/day) and the OCS-DC jacket foundation (one vessel installing four pin piles/day) may occur during the OCS-DC foundation installation campaign. However, the mitigation measures and associated zone sizes for concurrent installation of WTG MPs and the OCS-DC jacket foundation included in this Plan are based on the proximal assumptions which result in the most conservative ranges to auditory (marine mammal and sea turtles)/physical (fish) injury and behavioral thresholds.
The OCS-DC will be installed on a jacket foundation that will be driven into the seabed using a MHU3200 or MHU3000 impact hammer with a maximum hammer energy of 3,200 kJ. The underwater acoustic analysis and exposure modeling assumed a four-legged OCS-DC jacket foundation consisting of eight pin piles (two pin piles per jacket leg), each 4 m in diameter. The final engineering design of the OCS-DC jacket results in diameters of 2.44 m. Installation of a single jacket foundation is expected to require approximately 48 hours of pile driving per jacket (which includes up to 6 hours of pile driving per pin pile). The duration of pile driving will be determined by soil characteristics. The OCS-DC foundation installation is expected to occur at any point in late Q3 2025; however, the impact pile driving would likely occur within a 3-day period (72 hours) including waiting time between each pin pile installation for related installation activities (e.g. relocation of hammer/crane/vessel). A noise abatement system (NAS) consisting of a double big bubble curtain (DBBC) will be deployed during installation of the OCS-DC jacket foundation to reduce sounds propagated into the marine environment. Information on components of the noise abatement systems is provided in Appendix A.