Offshore wind energy is often seen as carbon- and pollution-free, since it is generated without emissions. However, producing this energy does involve using support vessels, helicopters, and generators (needed to run navigation lights when there is too little wind)—meaning that pollutants are emitted during preconstruction, construction, operation, maintenance, and decommissioning of offshore wind farms. The Bureau of Ocean Energy Management needed to assess these potential emissions along with the potential benefits of offshore wind.
ERG developed a software tool based on the hours of operation of support vessels, helicopters, and generators needed for all phases of an offshore wind farm project. ERG applied these activity data to the latest U.S. Environmental Protection Agency-authorized emission factors to calculate emissions. We also considered avoided emissions from landside electricity power plants related to the clean energy produced from the planned offshore wind power project. To ensure that the software accounted for a different mix of power sources for a local grid and to be consistent with EPA methods, we developed these estimates based on emission factors from EPA’s AVERT model.
Offshore developers can use the tool we developed to provide BOEM with required data for their lease permits. As well, BOEM can use the tool to support the development of required environmental impact studies.