Maine researchers will spend a month in the Netherlands working at one of the world’s most advanced testing facilities, battering scale models of offshore wind turbines with every wind and wave simulation imaginable.
The goal is to develop enough robust data to allow engineers to design and thoroughly test turbine models to be used 20 miles off the coast, in the deep waters of the Gulf of Maine, said Habib Dagher, head of the University of Maine’s Advanced Structures and Composites Center.
Dagher and other UMaine professors will rotate on the work at the Marine Research Institute Netherlands, where three models will be tested for four weeks, over two eight-hour shifts each day. Students from UMaine and from Maine Maritime Academy will assist in the Department of Energy-funded research project. The testing will begin in mid-April, said Dagher.
The DeepCwind Consortium plans to have enough deepwater turbines far off the coast of Maine in place by 2030 to generate 5 gigawatts of power for the state, which would be the rough equivalent of two nuclear power plants.
The consortium is now doing research and development work. Out of 14 designs received, they have identified six they believe to be viable. They are now building 1/50th scale models of three floating turbine designs. One has a vertical underwater tube that will be filled with water as ballast, tethered to the ocean floor. Another is a platform used by the petroleum industry for floating oil rigs, with a buoyant platform tethered by taut cables. The third is a semi-submersible, three-hulled float model, also tethered to the ocean floor.
The actual turbines would be about 300 feet high, from the surface of the ocean. The models will be about six feet tall. The group had looked at wave basins around the country, but none could program in the conditions needed to simulate the Gulf of Maine, said Dagher.
“We know the statistics of the waves and winds off the coast of Maine – we know them very well,” said Dagher.
MMA and UMaine worked with the Massachusetts Institute of Technology to develop a wind tunnel that will work in conjunction with the wave basin, Dagher said. UMaine is now building a research facility that will incorporate the design; the Netherlands facility will be used in the meantime.
The turbines will be subjected to average wind and wave conditions, and to extreme ones, as well. They will be monitored and tested, and researchers will also study how changing the pitch of the turbine blades to respond to conditions affects the stresses on the structures.
The consortium is also designing a 1/3 scale model to be put out near Monhegan island for testing to begin a year from July, said Dagher. UMaine is working with industry partners including Bath Iron Works and Cianbro Corp. on that model.
UMaine has 10 years of wind and wave data from the area. It has done a geophysical investigation of the ocean bed there, and has radar set up on the island to monitor migratory bird patterns. Researchers will investigate how the turbine affects the ecosystem in the area, above and below water, he said.
The project is part of a drive to diversify Maine’s energy sources. Dagher said the goal with the deepwater offshore wind research is to bring the cost of construction and technology down to a level where the power is cheap, at 8 to 10 cents per kilowatt hour by 2020.
“Maine has to look at a mix of energy resources to deal with our needs. We don’t want to put all our eggs in one basket — we’ve seen what happens to oil, what is happening to nuclear,” said Dagher. “We’ve got to look at a portfolio of solutions so the state can move forward safely.”
In contrast to shallow-water turbines, which are sunk into the ocean floor, deepwater turbines would be built onshore and hauled out to the wind farm site, keeping costs down.
The general thought on the manufacturing process is Cianbro would fabricate the components to the floating turbines, and they would potentially be assembled at BIW, said shipyard spokesman Jim DeMartini.
“We don’t know where this is all going to end up in the future, but if anybody’s talking about large-scale steel structures in the Gulf of Maine, we’re interested,” said DeMartini.
Vigue said he saw real potential for Maine, not just in diversifying the energy sources, but in developing and building next-generation offshore wind technology.
“I do not think we’ve come anywhere close to achieving what we’re capable of achieving in this state, from an economic perspective,” said Vigue. “This is an opportunity not only for Maine but for this country to become an exporter of much of this equipment on a global basis.”
Vigue noted that General Electric makes the blades for its gas turbines in Bangor.
“What’s to say we can’t manufacture the next generation of [wind] blades, the next generation of turbines?” said Vigue.