TPT January 2014

Global Marketplace

tower would be equipped with an “anti-ice cone” that would protect it from crushing ice floes that critics have warned would destroy any freshwater wind turbines. The inverted steel cone, filled with concrete and attached to the towers some feet below the surface of the water, would protect them from “keel ice” (broken and refrozen chunks of ice) pushing up against the structures from below. The tower, or pole, would weigh about 600 tons, said Stanley White, a Connecticut-based engineer working with Ocean and Coastal Consultants, also of Connecticut but now owned by Denmark-based international engineering company COWI A/S. I ntended for hard service Finnish engineer Esa Eranti, an acknowledged ice expert in the offshore area, told Mr Funk that oil companies pioneered the cones 30 years ago to protect drilling rigs. The method has since been employed to protect wind turbine towers inshore in Finland, where temperatures can plunge well below zero and where snow and ice cover much of the land from December to April. “The Gulf of Finland, part of the Baltic Sea, is very similar to the Great Lakes region,” Mr Eranti said. “The conditions – waves, wind and ice – are very similar.” The solution was one of four developed by the team members, who designed the towers to withstand up to twice the forces of a 50-year storm. The final decision was taken on the basis of cost, installation time, and whether the expertise, manufacturing and shipping on offer in the region could get the job done, said Dr Wagner. The towers would be fabricated in 2016, a job that three Ohio companies are capable of doing, said Mr Karpinksi. Representatives from the three companies, recommended by the manufacturing supply-chain group Great Lakes Wind Network, have already met with LEEDCo. Installation in the lake is planned for the spring of 2017. › On an environmental note, the team assembled by LEEDCo observed that turbine towers often re-establish thriving fishing grounds. Mr Funk was told that, with a tweak of the electrical gear, the six turbines planned for Lake Erie could help push oxygen into “dead zones” in the water, created by algae blooms consuming dissolved oxygen. To judge from reader reaction to the Plain Dealer coverage of the Lake Erie project, contrarian views on wind power generation show no sign of abating. Among the more temperate responses is this, much abbreviated, from a local resident: “Please Google europe wind farms failing and read what is going on in Europe with wind energy: increasing problems with wind turbine failures, unsustainable government subsidies, high maintenance costs, negative environmental impacts, increasing citizen disenchantment with wind power whether on land or water, and its continued broken and unfulfilled promises . . . Many of the same issues that wind farms create on the land do not disappear when located in the water.”

Energy Familiarity with North Sea and Baltic Sea conditions informs an innovative project for embedding wind turbines in Lake Erie “This is all about having a foundation that will work in these icing conditions and that therefore will work anywhere in the Great Lakes.” (“Lake Erie Wind Turbines Viable, Say Engineering Firms with North Sea Experience,” 23 September) David Karpinski, vice-president of operations for Lake Erie Energy Development Co – or LEEDCo, LLC – was outlining for the Cleveland Plain Dealer the preliminary results of a six-month feasibility study by European and American engineering firms that have partnered with LEEDCo. The non- profit corporation was formed to test the concept that turbines can survive in the five ice-choked Great Lakes; but also to determine whether or not they can be built inexpensively enough to compete with land-based power plants. Together with Mr Karpinski and LEEDCo president Lorry Wagner, five engineers from European-based firms with decades of offshore experience building wind turbines and oil drilling platforms described to Plain Dealer business reporter John Funk a solution that they believe satisfies both criteria. The six turbines in the pilot wind farm planned for Lake Erie would not need steel and concrete foundations drilled into the bedrock under the lakebed. Instead, each turbine would sit atop a single but very large-diameter pole, or tower, much like those used for land-based wind turbines. “This is the most common foundation used in the business today,” said Dan Woodman, of British-based Offshore Design Engineering, a company with extensive experience building offshore structures, including platforms in the North Sea. Favouring the single-pole approach, he said, is the fairly lightweight (70-ton) turbines that LEEDCo plans to use, and the relative shallowness (60ft in depth) of the water at the site of the projected wind farm. The “monopole”, made of rolled and welded plate steel, would be driven into the 80ft of sand, clay and glacial material under the lake before coming to rest on the shale bedrock. Each

The weather conditions around Lake Erie present their own unique challenges

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J anuary 2014