Client: Bureau of Ocean Energy Management and HDR, Inc.
Location: Block Island, Rhode Island
Block Island Wind Farm began operation in 2016 as the nation’s first offshore wind farm. The site’s five wind turbine generators can generate up to 30 megawatts of renewable electric energy, enough for 17,000 homes.
The island itself had previously been powered by five diesel engines burning more than a million gallons of fuel annually, but now relies solely on energy from the offshore wind facility, reducing local electric rates by nearly 40 percent. In addition to the five 6-megawatt wind turbine generators, the project also included placement of 34.5-kilovolt submarine transmission cables running from the wind farm to Block Island and onto the mainland grid.
Under contract to the Department of the Interior Bureau of Ocean Energy Management (BOEM), through HDR, Inc., EA developed a field ambient air monitoring plan to assess the potential air quality impacts from marine, submarine, and terrestrial construction activities. Potential sources of air emissions from construction activities included marine vessels and marine construction equipment at the five wind turbine generator sites; the submarine cable paths between the wind turbine generators, from the windfarm to Block Island, and from the island to Narragansett; and the substation construction site on Block Island. After further discussions with the project developer, BOEM elected to limit the possible installation of ambient air monitoring to only onshore locations.
BOEM also requested that EA review and evaluate the report: Visualization Simulations for Offshore Massachusetts and Rhode Island Wind Energy Area – Meteorological Report (15 January 2014), to determine if onshore monitoring at Block Island and Newport, Rhode Island and at Martha’s Vineyard or Nantucket, Massachusetts could provide meaningful insights into the likely air quality impacts from construction activities. The factors considered in this evaluation included the distances of the potential monitoring locations from the wind farm site, prevailing winds at each location, and relative magnitude of emissions from the wind farm construction activities and other sources of air emissions in the region, including commercial shipping, ferry and recreational boat traffic, and stationary emission sources in proximity to potential onshore monitoring locations. Based on the expected capacity of the marine diesel engines that would be deployed to support construction of the wind turbine generator foundations, EA determined that significant ambient impacts from air emissions would not extend beyond a range of approximately 10 kilometers from the wind turbine generator sites and that onshore ambient air monitoring at Block Island, Newport, Martha’s Vineyard, and Nantucket would not be necessary. EA’s evaluations contributed to expediting permitting and construction for the project.
