Partnering with WREN, questionnaires are sent to offshore wind energy developers around the world who are involved in environmental monitoring. This page provides contextual project information and highlights environmental monitoring, providing links to available data and reports. Content is updated annually.

Coastal Virginia Offshore Wind (CVOW)

Description

The Coastal Virginia Offshore Wind (CVOW) consists of a 2-turbine pilot, which became operational in October 2020, and a 2.6 GW commercial-scale project, which is currently under construction. The pilot is located 27 miles off the coast of Virginia Beach and is the first offshore wind farm installed in federal waters and the first offshore wind project developed and owned by an electric utility company (Dominion Energy). The commercial-scale project will expand to include 176 turbines, 3 offshore substations, and 9 buried offshore export cables extending to an onshore cable landing area. The project, scheduled to be completed in 2026, is expected to generate enough electricity to power 660,000 homes.

Location

The project is located in federal waters 27 miles off the coast of Virginia Beach, Virginia (USA).

Licensing Information

  • 2022, May: Submitted CWA Section 404, CWA Section 408, and RHA Section 10 application. Decisions anticipated Q3 2023
  • 2022, April: Submitted FAA Form 7460-1, notice of proposed construction or alteration. Determinations received May 2022
  • 2022, March: Submitted initial application for CAA OCS Air Permit
  • 2013, November: Commercial lease with Virginia Electric and Power Company (dba Dominion Virginia Power) for the Virginia Wind Energy Area

Project Timeline

  • 2024-2026: Project construction and commissioning
  • November 2024: 78 monopile foundations and 4 offshore substation foundations were installed
  • November 2023: Transmission construction started
  • 2023: BOEM Record of Decision
  • September 2023: Final Environmental Impact Statement Issued
  • 2022: CVOW approved by Virginia State Corporation Commission (SCC)
  • 2022: Virginia State Corporation Commission review
  • 2020: Pilot project turbines installed
  • 2020: Construction and Operations Plan (COP) submitted to BOEM
  • 2019: BOEM approves RAPR
  • 2017: Submission of Research Activities Plan Revision (RAPR) for BOEM’s Review
  • 2017: Ørsted retained as EPC contractor for the project
  • 2017: Site assessment plan approved by BOEM
  • 2013: Dominion Energy executed lease agreement with Bureau of Ocean Energy Management (BOEM)

Key Environmental Issues

Prior to constructing the pilot turbines, more than two dozen studies and surveys were conducted to ensure protection of ocean life and avian species. The data and lessons learned from those studies are informing the development of the commercial project. 

CVOW is the second facility to be studied under BOEM’s Realtime Opportunity for Development Environmental Observations (RODEO) program. RODEO aims to make direct, real-time measurements of the nature, intensity, and duration of potential stressors during the construction and initial operations of selected offshore wind facilities. Underwater acoustic monitoring was conducted during the construction of two monopile wind turbines (one with a bubble curtain and one with a double bubble curtain).

Additionally, Dominion contracted with Normandeau Associates Inc. to provide postconstruction monitoring for the pilot turbines. Normandeau's Acoustic and Thermographic Offshore Monitoring (ATOMTM) systems are deployed on platforms underneath the two turbines. They collect thermographic and natural light imagery within the rotor swept zone and the vicinity of the wind turbine 24/7 during the monitoring period. Additional ATOMTM sensors include bird and bat acoustics and VHF/MOTUS Nanotag receivers and antennae. Normandeau also conducted six boat-based surveys every other month during the first year of operations using a transect design. Additional information on this monitoring can be found here. 

Metadata Documents

Environmental Papers and Reports

Environmental Monitoring: Coastal Virginia Offshore Wind (CVOW)

Phase Stressor & Receptor Design and Methods Results Publications Data
Baseline Marine Mammals Passive acoustic monitoring
Four stationary bottom-mounted recorders were deployed across the continental shelf, and six recorders were placed within the wind planning area. Data were recorded between 2015 and 2017. 		Complete
Right whales were found to be most common in the area, with Baleen, humpback, and fin whales also occurring. All whales occurred with seasonal variation. 		Salisbury et al. 2018 No data publicly available.
Baseline Bats Passive Acoustic Monitoring
Stationary acoustic recorders on 5 structures off the coast of Virginia, across all seasons 2012-2019. 		Complete
Tree bat occurrence was found to be negatively related to wind speed and positively related to temperature and visibility. 		True et al. 2021 No data publicly available.
Baseline Bats Passive Acoustic Monitoring
Acoustic bat detectors were deployed during offshore geophysical and geotechnical survey activities in 2020-2021 within the Lease Area. 		Complete
Bat activity rates were low, with no federally listed species detected. 		Tetra Tech Inc. 2022 No data publicly available.
Baseline Birds Digital video, boat surveys, telemetry
From 2012-2014, wildlife off the Eastern Seaboard were observed with a series of digital video aerial surveys, boat surveys, satellite telemetry, and nocturnal migration monitoring. Work resulted in the Mid-Atlantic Baseline Studies (MABS). 		Complete
Species common to the mid-Atlantic coast were identified. 		Williams et al. 2015 No data publicly available.
Baseline Birds Satellite transmitters
Peregrine Falcons and Merlins were satellite-tagged. Study by BRI at three research stations along the north Atlantic coast. 		Complete
Peregrine Falcons and Merlin migration routes along the Atlantic Flyway were identified. 		Tetra Tech Inc. 2022

Desorbo, C.
Baseline Birds Satellite transmitters: Telonics TAV-2630 and IMPTAV-2640
236 adult birds were tagged and tracked with Platform Terminal (satellite) Transmitters (PTTs). 		Complete
Fine-scale movement patterns of three species (Red-throated Loon, Surf Scoter, and Northern Gannet) were identified in the mid-Atlantic coast. 		Spiegel et al. 2017, Stenhouse et al. 2020

Stenhouse et al. 2020

Stenhouse et al. 2020

Stenhouse et al. 2020
Baseline Birds Digital VHF (very high frequency) transmitter tags
3,955 individuals of 17 shorebird species were tagged with VHF transmitters between 2014 and 2017 at 21 sites dispersed across North and South America. Movement was tracked via a collaborative radio telemetry network. 		Complete
In analysing movement of the birds through Federal waters of the Atlantic Outer Continental Shelf, most flights were found to be above the rotor swept zone (RSZ). 36% of flights were in the RSZ in fall, and 24% in spring. 		Loring et al. 2021 No data publicly available.
Baseline Fish Multibeam echo sounder, side scan sonar, visual imagery
Visual imagery taken during grab samples were analysed for organisms, including fish. Surveys were undertaken using SSS and MBES in the offshore project area and cable corridor. 		Complete
Essential fish habitats have been designated in the project area for 33 species. Results are detailed in appendix E: essential fish habitat assessment. 		Tetra Tech Inc. 2022 No data publicly available.
Baseline Invertebrates Grab samples, digital imagery
74 grab sample stations were used to collect data. Water quality measurements were taken, and infaunal organisms were sieved and collected for identification. Underwater images were also collected to corroborate sediment grab samples. 		Complete
No hard bottomed habitats were observed. 26 taxa were identified, including hard clam and blue mussel in the export cable route. 		Tetra Tech Inc. 2022 No data publicly available.
Baseline Marine Mammals Protected Species Observer sighting, passive acoustic monitoring
Data was collected during project-related vessel-based surveys between 2018 and 2019 in a study area encompassing the Lease Area. Additional sighting data were collected between 2020 and 2021. 		Complete
Marine mammals sighted are summarized in tabular form. 38 species were observed (7 large whale, 20 dolphins, 5 beaked whales, 1 porpoise, 1 manatee, and 4 seals) either seasonally or year-round. 		Tetra Tech Inc. 2022 No data publicly available.
Operations Noise

Marine Mammals 		Underwater Sound Monitoring
A suite of hydrophone arrays was deployed to monitor pile driving sound and seafloor particle motion during construction of the two pilot project turbines. The primary goal was to evaluate the efficacy of bubble curtains deployed around the turbine. The arrangement of the passive acoustic monitoring also allowed studies of azimuthal and range dependencies of pile driving sound propagation. 		Complete
Data showed the bubble curtain effectively reduced pile driving noise above 200Hz, and a significant azimuthal dependency was observed. 		Lin et al. 2022, Amaral et al. 2021, WaterProof Marine Consultancy & Services BV. and Dominion Energy 2020 No data publicly available.
Operations Noise Operational Sound
Operational sound was measured between Dec. 14, 2021, and Feb. 2, 2022, using a Geosled equipped with a tetrahedral hydrophone array and two Several Hydrophone Recording Units (SHRU). Additionally, two Ocean Bottom Seismometers were deployed. 		Complete
Underwater noise levels recorded during turbine operations were relatively low, ranging from 120 to 130 dB re 1 μPa except during storms when the received levels increased to 145 dB re 1 μPa. Operational phase sound levels were substantially higher (10 to 30 dB) than those previously recorded at the Block Island Wind Farm (BIWF) at frequencies below approximately 120 Hz. 		Ampela et al. 2023 No data publicly available.
Construction Habitat Change

Invertebrates 		Atlantic surfclam (Spisula solidissima) monitoring
The 2024 Surfclam Survey evaluated surfclam abundance, distribution, and population structure using a hydraulic dredge at 38 stations in lease and control areas. CPUE, biomass, and fishable biomass were estimated via swept area calculations and dredge efficiency (0.65). Age analysis used shell rings with a von Bertalanffy growth model, while genetic testing identified S. solidissima and S. similis distributions. A Petersen grab sampler collected sediment and juveniles, and a Castaway CTD recorded bottom temperature and salinity. Bycatch species were also documented. 		Complete
The 2024 Surfclam Survey found high biomass but low exploitable biomass within the CVOW lease area, with biomass highest in the south and 50 times lower in the north. Recruitment was consistent over the past 5–6 years, but older surfclams (>6 years) were absent, suggesting lower survival. Genetic analysis showed a mix of S. solidissima and S. similis, with S. similis more common in warmer, shallower waters. Juvenile surfclams were present in all areas, indicating recent recruitment. Environmental data showed minor temperature and salinity differences, unlikely to explain biomass patterns. 		Rudders et al. 2024 No data publicly available.
Construction Noise

Marine Mammals 		Passive acoustic monitoring
A suite of hydrophone arrays was deployed to monitor pile driving sound and seafloor particle motion during construction of two wind turbine towers in the Coastal Virginia Offshore Wind (CVOW) project in May 2020. The primary objective of this passive acoustic monitoring (PAM) work was to assess the effectiveness of bubble curtains for underwater noise mitigation. 		Complete
PAM data showed that the bubble curtain effectively reduced the pile driving noise above 200 Hz, and a significant azimuthal dependency was observed. Statistical analyses of pile driving noise will be presented, along with recommendations for future wind farm construction monitoring, especially on marine mammal acoustic monitoring during construction. 		Lin et al. 2022 No data publicly available.