The University of Maine has narrowed in on the Midcoast as the most likely area for future offshore wind development in a 567-page report released on February 23.

The report, which compiles economic, policy, electrical grid integration, wind and wave, bathymetric, soil, fisheries, and environmental research, has been in the works for six months and includes information from 13 different organizations and over 35 authors.  

Several areas in Penobscot Bay, including Searsport, Islesboro and Rockland Harbor are identified as having water depths and the facilities necessary for project construction and on-water staging. According to Bob Lindyberg, assistant director at the advanced structures and composites center at the University of Maine and director of the DeepCwind consortium, there are three different types of turbine platforms that could be used offshore in the Gulf of Maine. The first two, tension leg platforms and a semi-submersible platforms, can be almost entirely built at a dock or pier side. However the third, a spar design, can have a draft of 100 meters and requires very deep and relatively sheltered water. “The area we’ve found that has the most potential for building and deploying a spar is up in Penobscot Bay. It’s probably the deepest and most sheltered areas on the coast to build and deploy a spar and still be able to tow it offshore,” says Lindyberg.

The report also analyzes the high-capacity interconnection points along the coast that would be necessary to tie an offshore wind project into the grid. While a number of potential interconnection points and cabling routs along the coast are considered, Bath, Wiscasset, Boothbay and Rockland, all located in the Midcoast, are identified as being the “best and most flexible interconnection points.”

While the report certainly hones in on the Midcoast area, it is only meant as an information document. “The Midcoast, and specifically the Searsport area, looks particularly favorable for a variety of reasons,” says Lindyberg. “However, the decision about what port or ports to use has really got to be made by the developer.”

The report was written in response to the passage of the bill An Act to Implement the Recommendations of the Governor’s Ocean Energy Task Force (Public Law 2009, chapter 615), which directed the Maine Public Utilities Commission (MPUC) to issue a request for proposals (RFP) for a 25 MW deep-water offshore wind project.

The goal of the report, according to Lindyberg, “was to pull together all of the accumulated knowledge that exists out there on the Gulf of Maine-grid integration, supply chain, stakeholder knowledge-all the things that a wind developer will need to know if they are going to submit an application for the RFP.”

The law requires that the development be sited a minimum of 10 nautical miles from any inhabited area of the state (including islands); that it is installed in waters of at least 300 feet in depth; that it be capable of expanding to 100 MW or more; and that it be able to generate power that is sold to the mainland grid at minimal impact to ratepayers.

Proposals are due by May 1 but construction is not likely to begin for at least another five years as projects will require a number of federal and state permits.

According to Dr. Heather Deese, senior programs director at the Island Institute and a co-author of the stakeholder section of the report, a 25 MW project will include five to seven turbines sited between a kilometer and a mile apart with exclusion zones around each turbine for navigation safety. Stakeholder concerns voiced in the report include the impact such a project would have on current uses, the costs to ratepayers, and potential local benefits, among other things.

Gillian Garratt-Reed is editor of The Working Waterfront