This floating offshore wind turbine was put in place off Castine Maine as a concept test in 2013. It has been putting energy to Central Maine Power since then. Photo by Jplourde UMaine, Wikimedia Commons. (https://bit.ly/OffshoreME).
George Harvey
Along the northern East Coast of the United States, from North Carolina to Maine, offshore wind power is now being developed as quickly as possible. Unfortunately, up until now that has not been very fast. There have been holdups, and for a long time, while the world had installed thousands of turbines in offshore wind farms, the U.S. only had installed seven turbines in tiny two projects. This year, a third project was completed and turned on, with twelve turbines and a capacity of 130 megawatts.
One thing that slowed things down is the Jones Act, a law that specifies things about ships carrying cargo from one place in the United States to another: The ships must be built and registered in the U.S. They must also be crewed by U.S. citizens for U.S. owners. The problem is that the ships used for installing offshore wind turbines are highly specialized, and they were not being built in this country. Now, solutions for that are coming.
It is important that Maine is making its place with offshore wind power. In 2020, Maine’s Governor Janet T. Mills directed the state’s Department of Transportation to study ports for their potential to support establishment of the state’s offshore wind industry. Searsport was one, and this was rather predictable because its port, in Penobscot Bay, is one of the best deep-water harbors in the state. Searsport is not well known, because the town’s population is not very large, but it would be a good place for industries that support offshore wind farms.
One advantage Searsport has is Sears Island. Its 941 acres were already owned by the state. It had been divided into two parcels of land in 2009. The larger of these is a reserve of 600 acres, and the other was set to be used by the Maine Department of Transportation for later, unspecified development. This smaller lot was what the state was considering as the wind hub. As it happens, not all of that smaller parcel is needed to for the purpose, and only 100 acres are to be put to use.
We should be clear about this. Sears Island is not being considered as a site for a wind farm or any part of one. It is being considered as a site for various kinds of activity to support construction and service of offshore wind farms. It is a site for factories and the port facilities they need to load the components they make onto ships, so they can be taken to offshore sites for use.
A recent announcement from the governor’s office says, “The proposed port would be a purpose-built facility for floating offshore wind fabrication, staging, assembly, maintenance, and deployment. With deepwater access to the port development site, Maine has the potential to establish a premier location for the industry and help meet growing demand in the U.S. for offshore wind port infrastructure.”
There are different ways to assemble offshore wind turbines. The first has fixed foundations, and the second is floating.
Fixed foundation: The traditional way is to take a foundation out to sea from a port, put it into its correct site on the seabed, and then build on it. A tower must be installed, and towers are usually taken out in pieces. Then a specialized ship is used to assemble the tower at its site. Next, the nacelle, with the generator, must be lifted in place by a crane that is taller than the tower. Such a crane is carried on a jack-up ship, raised out of the water on legs that give it a firm foundation on the sea floor. And at some point, often after when the nacelle is put in place, blades have to be attached.
Floating: The coast of Maine does not have sufficient shallow areas for big wind farms of such traditional design. Instead, the approach to be used is to put up floating turbines, which do not have firm foundations. In such a case, a floating base, the tower, and the turbine with its blades, are assembled in a port. They are then towed out to their places at sea. There, they are anchored in place. That is the approach to be used at Sears Island.
After the turbines are sited, they must be connected to submarine transmission lines, which need to be connected to substations, which need to be connected to the grid on land. The cables need specialized ships to put them in place, at the least, and may need factories to make them. The substations are very large, need to be built and towed out to sea.
Governor Mills recently announced that Sears Island had been chosen as a site to support construction of offshore wind farms. Now people can be hired to build factories, to work in them, crew ships, construct turbines, lay transmission lines, and on and on. Other workers will be needed to support those who are actively working on the wind projects, and these will have many job skills, ranging from bank tellers and cooks to barbers and laundry workers.
The work is just starting, but it will almost certainly go on for years.
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