The University of Maine has done what renewable energy developers have tried to do for years: install a grid-connected offshore floating wind turbine off of the U.S. coast – albeit, on a much smaller scale.
The prototype is not commercial scale as it is a one-eighth scale version of a 6MW unit and has a 20-kW turbine on top, Elizabeth Viselli, manager, Offshore Wind Programs and Global Communications with the University of Maine, told TransmissionHub.
“Right now, it is moored off of Dyces Head in Castine, Maine – it’s about  or 400 feet from shore,” she said. “It is grid connected and we flipped the switch, connecting it to the grid late [in the week of June 17].”
The project is the first offshore wind turbine in North America and the first offshore wind turbine in the world to use concrete floating, Viselli said. Unlike hulls and towers made of steel, this turbine’s hull is made of concrete and the tower is a composite, she said.
“We believe that it’s going to lower the cost of energy to 10 cents/kWh by 2020,” which is the U.S. Department of Energy’s (DOE) goal for it to be competitive with other forms of energy, she said. “We believe this technology can do it, so we’re very excited to be the first and to be breaking ground there, and we hope that it will help spur the industry forward.”
The prototype has a small cable that is connected to the Central Maine Power(CMP) grid.
CMP’s parent company is Iberdrola USA, which is a subsidiary of Iberdrola S.A.
The installation is not far off the shore of Castine, which sees waves and winds that are one-eighth the scale of waves and winds farther offshore, where wind energy potential is greater. The university will deploy the project at least through June, Viselli said.
Using instrumentation, the prototype is collecting data on the motions of the turbine – how its platform reacts to the winds and waves of the Gulf of Maine.
At the same time, a floating LIDAR buoy is deployed next to it, taking measurements of wave height and speed, current, wind speed at hub height, as well as information about the ecological environment, involving birds, bats and marine mammals.
“We have data about the physical and ecological environment that we’re collecting, alongside data about the movements of the floating platform,” she said. “All of that information will be used to optimize the design of the 6MW system [the Aqua Ventus I project].”
The plan is, after testing is done at Castine, to bring the prototype to the university’s deepwater test site off of Monhegan Island. It will not be grid-connected at Monhegan.
The prototype effort was an approximately $12m DOE-funded program and included permitting, environmental monitoring and design of the unit over the last five years, Viselli added.
The floating wind turbine features a unique semi-submersible platform that uses a lower cost concrete foundation in addition to a lighter weight composite tower, DOE said in May.
As part of the five-year project, the Maine Maritime Academy helped test and conduct analysis on those pioneering designs, while Pittsfield, Maine-based Cianbro Corporation leveraged its experience in maritime energy infrastructure and ship building to construct this first-of-its-kind wind energy system, DOE said.
“The Castine offshore wind project represents a critical investment to ensure America leads in this fast-growing global industry, helping to bring tremendous untapped energy resources to market and create new jobs across the country,” Jose Zayas, director of DOE’s Wind and Water Power Technologies Office, said in the May 31 statement.
DOE noted that according to a recent report it commissioned, a U.S. offshore wind industry that takes advantage of this abundant domestic resource could support up to 200,000 manufacturing, construction, operation and supply chain jobs across the country and drive more than$70bn in annual investments by 2030.
In Maine, as with other areas off U.S. coasts, the bulk of that renewable energy resource lies in deeper waters where conventional turbine technology is not practical, DOE said, noting that innovative floating offshore wind turbines, like the one in Maine, will open up new economic and energy opportunities for the United States.
Bigger plans ahead
The New England Aqua Ventus I project is a 12 MW pilot offshore wind farm that will entail two 6 MW units to be operational in 2017, and the plan is to grow that to 500 MW to 1,000 MW by 2020, Viselli said.
That larger effort, Aqua Ventus II, will have approximately 168 turbines, each with 6 MW of capacity. Its cost is not yet known.
The University of Maine currently owns Aqua Ventus II, but it is spinning off the company, called Aqua Ventus Holdings LLC, to commercialize the technology. Both New England Aqua Ventus I and II will be privately owned and operated, she added.
The 12 MW Aqua Ventus I project is estimated to cost approximately $93.3m, which includes permits, environmental monitoring as well as construction, deployment and operation of the project, and laying the cable.
The deepwater offshore wind test site off of Monhegan Island is in state waters, which requires a special permitting process.
“It’s an expedited permitting process, so it’s a bit more streamlined than if we were in federal waters,” Viselli added. “We have not yet obtained or applied for permits.”
The estimated year-long permitting process will begin in 2014, but initial consultations with the various agencies involved have begun. “Everyone is very positive and excited about this project and happy to see it expanding from the one-eighth scale,” she said.
Monhegan Island is about 10 miles from the mainland and the test site is about 2.5 miles from Monhegan Island, so the project will be about 12.5 miles from the mainland.
“We will be laying a 25 MW capacity subsea cable that will go to Monhegan Island and then to the mainland,” she added, noting, “We plan to install those turbines and the cable in 2016 and 2017.”
The university has partnered with Senergy, which does a lot of the subsea transmission cable work for offshore wind farms in Europe, and has acquired a company in Maine called SCG Engineering.
Noting that there are a limited number of interconnection points to the grid for the project’s capacity, Viselli said siting may be an issue.
“We have to be smart about where we site these [projects],” she said. “Running cable underwater is expensive and there is a permitting process to be worked through, but there are subsea cables connecting islands. Even if we don’t necessarily have cables connecting offshore wind farms like they do in Europe, we certainly have plenty of underwater transmission cables in this country. … [M]aking sure that we can plug in at the right sites does affect site location for the farms.”
First in water, but size matters
Even though the prototype is the first grid-connected offshore floating wind turbine off of the U.S. coast, it is important to remember it is still a prototype, according to Patrick Gilman, an analyst with the Wind and Water Power Technologies Office at DOE.
“There’s an important distinction to be made there — the projects [like those proposed by Cape Wind Associates off the coast of Massachusetts and Deepwater Wind off the coast of Rhode Island] are commercial-scale — they’re utility generation projects that will be designed to” generate electricity for the grid for a long time,” he told TransmissionHub. “This is a technology test — they’re going out there with a scaled deployment of a device to test it on a temporary basis. So, it’s not the same kind of project. That having been said, it’s the first offshore wind turbine in the water in the U.S. that we’re aware of, but again, it’s not the same type of project.”
The American Wind Energy Association earlier this year said that there are 13 offshore wind energy projects in various stages of development spanning 10 states off the East and West coasts, as well as off the coasts of Texas and the Great Lakes.
Those projects represent more than 5,100 MW of offshore development with turbine sizes ranging from 3 MW to 6 MW, and include Cape Wind Associates’ Cape Wind project, Fishermen’s Energy’s project off the coast of New Jersey, Deepwater Wind’s projects and the Lake Erie Energy Development Corporation’s Icebreaker project in Cleveland Bay, off the coast of Ohio.
Cape Wind is owned by Energy Management.
DOE grants support offshore wind research
Charlton Clark, program manager for grid integration and resource management for the Wind and Water Power Technologies Office at DOE, said that the department has provided grants for research to about four projects “that are looking at different aspects of offshore transmission, [including] looking at what the economics are for building a backbone-type system versus just single radial connections going from each wind farm, landing to shore, and trying to get a better understanding of some of the technical impacts at a variety of different utilities and how integrating offshore wind, both from the Great Lakes and from the oceans, would impact those utilities’ operations.”
Those projects are being led by ABB, Duke Energy (NYSE:DUK), the University of Delaware and Cape Western Reserve University, he told TransmissionHub.
“We’re supportive of seeing commercial entities and utilities going out and trying to develop some offshore grid capability because it will be critical to any kind of offshore wind development in the future,” he said.
According to DOE, ABB received a $900,000 DOE grant and is assessing the likely impact of offshore wind development on the various regions of the U.S. from the electric utility perspective. This work includes developing energy production profiles, performing an initial integration analysis, and evaluating the applicability of traditional integration study methods and potential energy collection and delivery technologies.
Case Western Reserve University received a $540,000 DOE grant and is evaluating potential impacts of offshore wind on the electric grid in the Great Lakes region and determining requirements for interconnection, control systems, and the application of additional support for different transmission systems.
Duke Energy Business Services, meanwhile, received a $534,910 DOE grant and is examining the potential effects of offshore wind development on the Duke Energy Carolinas system by determining costs of upgrading the transmission system to support large-scale offshore projects, and assessing strategies for system integration and management.
DOE also noted that the University of Delaware received a $540,000 DOE grant and is examining potential effects of wind penetration on the mid-Atlantic electric grid and facilitating grid operations planning by identifying necessary system upgrades and grid management strategies to ensure reliable and efficient operation of the electric system.
In 2012, DOE announced seven offshore wind awards for projects in Maine, New Jersey, Ohio, Oregon, Texas and Virginia designed to commercialize offshore wind by 2017. In the initial phase, each project will receive up to $4m to complete the engineering, design and permitting phase of this award.
DOE will select up to three of those projects for follow-on phases that focus on siting, construction and installation and aim to achieve commercial operation by 2017. These projects will receive up to $47m each over four years, subject to Congressional appropriations.
As reported, the seven projects selected include efforts by Baryonyx in state waters near Port Isabel, Texas, Fishermen’s Atlantic City Windfarm off the coast of Atlantic City, Seattle-based Principle Power in deep water 10 to 15 miles from Coos Bay, Ore., and the University of Maine.
Gilman said those projects are all moving forward.
“We’re working with them and the other agencies to start their engineering and environmental permitting work,” he said. “A number of those groups have already started doing surveys to look at the environmental, geotechnical and other aspects of the site that they’re selecting. They’re working with the appropriate regulatory agencies so that they can be on the right track with respect to permitting and environmental review and they’re well on their way in their design work.”