The Bureau of Ocean Energy Management (BOEM) is initiating leasing of the seabed for offshore wind energy development on the outer continental shelf (OCS) in the Atlantic from Maine to Florida, with initial development planned for a series of Wind Energy Areas (WEAs) designated by the Department of Interior. Additional wind areas are under development and are currently considered to be Wind Call Areas (WCAs), leasing areas, and other set asides. Some of the proposed sites are located at or near the entrances to major ports, others are located at the seaward terminus of existing Traffic Separation Schemes (TSS), and many of the wind areas occupy locations along historical shipping routes. The siting of offshore wind farms has the potential to affect existing shipping along the Atlantic Coast; modifications to safe-access routes may be required.
The United States Coast Guard (USCG) has the authority to ensure navigational safety in U.S. waters. The USCG has undertaken the Atlantic Coast Port Access Study (ACPARS) to assess future port access and navigation needs for the Atlantic coast, at a time when the mix of shipping routes and vessels are likely to change due to factors such as the widening of the Panama Canal and opening of the Arctic Ocean to shipping. The presence of wind turbines off the Atlantic coast has the potential to affect shipping routes and activities. In order to safely incorporate the presence of offshore wind farms into ACPARS, the USCG requires information on the following: the effects of offshore renewable energy infrastructure on potential traffic density; the impacts of offshore wind infrastructure on shipping traffic including rerouting, funneling, and obstructions to navigation; and whether changes to safe access routes for vessels are needed with the installation of offshore wind farms, including modifications to fairways or TSSs.
BOEM entered into an Interagency Agreement in August 2012 with the US Department of Energy (DOE) to provide risk assessment expertise to the USCG development of ACPARS and BOEM’s OCS leasing. DOE assigned Pacific Northwest National Laboratory (PNNL) to provide an assessment of navigational safety risks (including collision, contact, grounding, and stranding). PNNL structured the project around several activities: 1) acquisition and processing of Automated Identification System (AIS) data; 2) geospatial analysis to elucidate historical shipping routes; 3) development of a data-driven numerical model to predict vessel movements in the presence of offshore wind farms; 4) enlisting expertise in navigation from an experts’ panel; 5) assessment of navigational risks from the presence of offshore wind farms; and 6) recommendations for changes to the navigation system to accommodate those changes.
This report focuses on the activities carried out by PNNL, in close coordination with BOEM and USCG, from August 2012 to November 2013, and indicates the priority actions for additional enhancement to the modeling system to be carried out from December 2013 through November 2014. The body of the report briefly introduces each step of the process, and reports on notable outcomes. Detailed descriptions, computations, and figures that represent each step are included in ten technical appendices.