Offshore Wind the Cape Wind Offshore Wind Farm: a First for The

Offshore Wind OFFSHORE USA The Cape Wind offshore wind farm: a first for the USA?

The Cape Wind proposal for the first US offshore wind farm has minimal impact on local marine and bird become a battleground between the project's proponents and life, and will not adversely affect commercial or recreational activity in the area. The pub- opponents, and may well influence the whole future of lic had until 10 January to comment on the renewable energy in the country. Paul Grad reports EIS' findings. The Corps is now preparing a final EIS, which is expected to be available irst proposed in November 2001 by grounds, and to meet the requirements of later this year. Cape Wind Associates, of Boston, the Massachusetts and regional renewable port- Despite the findings of the draft EIS, the Fproposed site in Massachusetts state folio standards." The decision was a signifi- proposed wind farm has been the subject of waters between Cape Cod and Nantucket cant milestone for Cape Wind. A intense debate, partly due to the fact that it Island at Horseshoe Shoals was chosen tak- spokesman for Cape Wind, Mark Rodgers, will be the country's first offshore wind ing into account the intensity of sustained said he was pleased and encouraged with the farm, and partly because it will be a very winds, the water depths and its accessibility Board's decision. He said the company must large installation. It will consist of 130 wind to the transmission grid. Prospective owner still raise capital for the project. He said if all turbine generators (WTGs). The rotors will and operator, Cape Wind is no stranger to goes well and all necessary approvals are have an overall tip to tip diameter of about the problems associated with such projects obtained, the wind farm will be producing 104m. The WTG nacelle hub height will be and, since its first proposal, has made up to 420MW of electricity for local com- about 75m from the mean lower water painstaking but steady progress in obtaining munities by 2007. datum. The turbines will be arranged in par- all the necessary approvals. The wind turbines - on monopole struc- allel rows with appropriate spacing to obtain tures - would be in an area outside of state optimal energy generation (630m [north- Milestone waters on the Outer Continental Shelf. south] and 1000m [east-west] between each Recently the Massachusetts Energy Facilities Under the Rivers and Harbors Act, the US turbine). Siting Board (EFSB) - the agency charged Army Corps of Engineers regulates all struc- with ensuring a reliable energy supply at the tures and work in navigable waters of the Public concerns least cost and environmental impact - has US. The Corps authority includes the Outer Faced with the prospect of an installation of approved the interconnection of the wind Continental Shelf. Late last year, the US such dimensions, members of the public farm's buried cables to the electric transmis- Army Corps of Engineers issued a draft were concerned that the wind farm would sion system in the state. The Board's deci- environmental impact statement (EIS) for become an eyesore, and spoil the area. This sion states that: "The power from the wind the project. The basic conclusions of the became one of the main concerns regarding farm is needed on reliability and economic draft EIS are that the project will cause the project. However, proponents of the project noted that, during most of the year, there is fog over the sea near the coast, and the turbines will not be visible from the shore at all. Besides, the nearest distance of the turbines to land will be about 7.6km. A spokesman for AWS Truewind, a research firm that consulted on the project, said photo simulations of what the wind farm would look like from the shore assume the clearest weather conditions (see picture, next page). From the shore, on a clear day, the wind farm will be visible about 1cm above the horizon and should not constitute an eyesore. Greenpeace, which is one of the strongest supporters of the project, also believes there is no need for concern over Site of the proposed first offshore wind farm in the USA at Cape Cod. Source: Cape Cod Times the turbines' visual impact. Kert Davies, US

research director for Greenpeace, said in group is bankrolled by wealthy summer some countries where offshore WTGs have home owners with houses overlooking been installed, as in Denmark, the wind Nantucket Sound. Of the $1.7 million the farm has actually become a tourist attrac- alliance raised in 2003, $1.3 million came tion. Greenpeace has taken its support for from 56 donors who gave $5000 or more. the project to local airwaves in a 30-second The top 20 contributors gave more than $1 television commercial depicting windmills million, the report says. Computer simulation of a view from the shore off the coast of England and a snippet from about 10km away from the Nantucket Sound a U2 song. Design and engineering wind farm (from a place called Cotuit) Despite the fighting, however, the design and caisson placed on the seabed to support the Debates and battles engineering details of the project have been WTG; and the monopole foundations, Nevertheless, the sometimes acrimonious well established. The WTGs will be arranged which are either prefabricated steel or con- debate between those for and against the so as to maximize the wind farm's energy crete pile systems driven or augured into the project continues. While the US Army generating capacity of 454W. This capacity is seabed. The gravity foundation system has Corps of Engineers is the principal agency based on the design wind speed of at least been used for several European WTG instal- reviewing the project, the wind farm is also 14m/s, up to the maximum operational lations where the soil or rock characteristics being scrutinized by 9 state agencies. For the speed of 25m/s. Based on an average wind at the bottom preclude the use of most part, state oversight is limited to the speed of about 9m/s, the net energy produc- monopoles. It requires a shipyard and dry effects of the underwater cables since that is tion delivered to the regional transmission dock near the site to construct and allow the the only part of the project in state waters. grid will be about 1.5GWh/a. The project foundation structures to be floated out to EFSB chairman Paul Alfonso drew attention will use pitch-regulated upwind WTGs with the site and sunk. It is an environmentally to the fact that the situation became some- active yaw and a three-blade rotor. The rotor more "brutal" system due to the foundation what clouded when the federal government blades will be pitched to prevent rotation structures' large diameter. The monopole altered the boundary of federal waters earli- when the wind speed exceeds 25m/s and will system is the best suited and preferred solu- er this year. A slice of the Cape Wind foot- also engage the disk brake system to positive- tion for offshore applications being a large print - where 8 to 10 turbines would be ly lock the rotor. diameter pile driven 15.2m to 27.4m into built - was suddenly in state waters. Several There are two basic foundation systems the seabed, depending on the load bearing other state hurdles remain, with several for existing offshore wind turbines: the grav- characteristics of subsurface marine sedi- more approvals expected from various state ity based foundations, which use a prefabri- ments. At Nantucket Sound the main sup- agencies. Meanwhile, a contentious battle cated, large diameter concrete and steel port tower will have a base diameter of has been waged in court between Cape Wind and the "Alliance to Protect Nantucket Sound". According to a report in the Cape Cod Times, the battle is about the more than 400 files containing Alliance strategy memos, donor lists, and emails on computers used by former alliance staff member, John Donelan. Cape Wind is fighting for access to the files as part of its ongoing libel suit against Donelan. The alliance, which has spearheaded opposition to the wind farm, hopes to keep the files under wraps. According to the report a Suffolk Superior Court judge ruled that the files should be turned over to Cape Wind for review. A few days later, attorneys for the alliance success- fully petitioned the court to keep them from Cape Wind until the alliance appealed the decision to a higher court. A spokesperson for the alliance said the files contained sen- sitive information about the alliance operations and financial backers that is propri- etary. The Cape Cod Times report says crit- ics of the alliance have charged that the Blyth offshore wind farm: the first in the UK. Photo: AMEC Border Wind

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about 5m at the mean low water the pile driving equipment, to datum plane. The monopole allow fish to move away from the structures will be spread through- area. To minimise impact on pro- out an ocean area of about 50km2 tected marine species, the draft and the electricity generated by EIS recommends that ships trans- each turbine will be transmitted porting materials and crew to the via a 33kV submarine transmis- project site travel at speeds well sion cable system to the Electric below 14 knots and that project Service Platform, centrally located vessels follow National Oceanic within the WTG array. The plat- and Atmospheric Administration form will then take the energy (NOAA) whale watching proce- from each turbine and transform dures while travelling to and from and transmit this electric power to the project area. Underwater the Cape Cod mainland via two sound monitoring will be carried 115kV alternating current subma- out during initial monopole con- rine cable circuits. The cable sys- struction. tems will make landfall in the Prior to construction, an ero- town of Yarmouth. From this sion and sedimentation control landfall, an upland transmission barrier will be installed to protect system will be installed in an the adjacent salt marshes. Erosion underground conduit system and sedimentation, dewatering within existing roadways and and storm water management right-of-way. plans will be developed, which will incorporate applicable best Environmental management practices for erosion impacts and water management during According to the draft EIS pre- construction. pared by the US Army Corps of The piles will be driven Engineers, the project will not mechanically into place, min- adversely affect ferry operations, imising seabed disturbance and commercial and sport fishing, turbidity associated with the boating, aviation or any other foundation installation. To miti- activity. The draft EIS, however, gate the potential impact on visu- presents a long list of possible al, archaeological and cultural environmental effects and, while resources, the draft EIS proposes stating these will all be minor, that the 115kV marine transmis- also presents a list of mitigation sion route be shifted to the west measures for each of them. It says to avoid several reported ship- there will be no major impact on wrecks. The upland transmission tidal or wind-driven currents route will be located entirely because of the small cross section- below ground within paved roads al area of the WTGs and the wide and existing utility right of ways spacing between them. It says to avoid visual impacts and installation of the submarine impacts on potential archaeologi- cables by jet plow embedment cal resources. will minimise sediment distur- It will be interesting to see how bance and suspension. The sub- the project progresses, considering marine cable system will be that the US wind energy potential buried to a minimum of 2m is estimated by the American below the seabed to avoid conflict Wind Energy Association (giving with fishing vessels and gear the Pacific Northwest Laboratory operation. During installation of as the source) at nearly 11,000 bil- the monopoles, impact from pile lion kWh annually - more than driving equipment will be min- twice the electricity generated in imised by using a "soft start" of the US today.

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