Data+Set+2

//**Rf S2.1** // // **4.** “Offshore Wind Development Activities”: In Europe, two offshore wind projects, totaling 200 MW, were installed in 2007, bringing total worldwide offshore wind capacity to 1,077 MW. In contrast, all wind projects built in the United States to date have been sited on land. Despite the slow pace of offshore activity, there is some interest in offshore wind in several parts of the United States due to the proximity of offshore wind resources to large population centers, advances in technology, and potentially superior capacity factors. The table on the right provides a listing, by state, of “active” offshore project proposals in the United States as of the end of 2007. Note that these projects are in various stages of development, and a number are either very early-stage proposals or reflect projects that are already in jeopardy of cancellation; clearly, considerable subjectivity is required in creating this list of “active” proposals. Several events in 2007 demonstrate that progress continues with offshore wind in the United States. Specifically, New Jersey issued a solicitation to provide financial incentives for an offshore wind project up to 350 MW in size, Ohio commissioned a study to investigate the feasibility of a 20-MW wind project in Lake Erie, the Texas General Land Office awarded the first four competitively bid leases for offshore wind power in the nation’s history, and the municipal utility serving the town of Hull, Massachusetts filed for (and in February 2008, received) initial state approval for four offshore turbines. More recently, Rhode Island has also issued an RFP for offshore wind. Also in 2007, the Draft Environmental Impact Statement for the highly publicized Cape Wind project in Massachusetts reached conclusions favorable to the project, and the U.S. Minerals Management Service made progress in executing its offshore wind regulatory responsibilities. Notwithstanding these developments, regulatory delays, turbine supply shortages, high and uncertain project costs, and public acceptance concerns have hampered progress in the offshore wind sector. In 2007 alone, for example, concerns about the high costs of offshore wind resulted in the cancellation of a 500-MW Texas project and the likely cancellation of a 150-MW New York facility, and put a 450-MW Delaware project in jeopardy (the latter two projects are included in the table on the right, as they remain at least somewhat “active”).”// ** //5.//** //GE Wind remained the dominant manufacturer of wind turbines supplying the U.S. market in 2007, with 44% of domestic turbine installations (down from 47% in 2006 and 60% in 2005).10 Vestas (18%) and Siemens (16%) vied for second place in 2007, with Gamesa (11%), Mitsubishi (7%), and Suzlon (4%) playing significant, but lesser roles.// //6. A number of large companies have entered the U.S. wind development business in recent years, some through acquisitions, and others through their own development activity or through joint development agreements with others. Particularly striking in recent years has been the entrance of large European energy companies into the U.S. market. The two largest developer acquisitions in 2007, for example, were the purchase of Horizon Wind by Energias de Portugal (from Portugal) and the acquisition of Airtricity North America by E.ON AG (from Germany), summing to nearly $4 billion in aggregate.
 * 1**. The U.S. wind power market surged in 2007, shattering previous records, with 5,329 MW of new capacity added, bringing the cumulative total to 16,904 MW. This growth translates into roughly $9 billion (real 2007 dollars) invested in wind project installations in 2007, for a cumulative total of nearly $28 billion since the 1980s
 * 2.** In terms of wind resources, there is abundant supply but each site has its own disadvantages and advantages ranging from extreme waves, costly structure (deep), limiting the seaward extant, close to breakwater.//
 * 3.** On a cumulative basis, after surpassing California in 2006, Texas continued to build on its lead in 2007, with a total of 4,446 MW of wind capacity installed by the end of the year. In fact, Texas has more installed wind capacity than all but five countries worldwide. Following Texas are California, Minnesota, Iowa, Washington, and Colorado.//
 * 7.** Private independent power producers (IPPs) continued to dominate the US wind industry in 2007, owning 83% of all new capacity (Figure 11). In a continuation of the trend begun several years ago, however, 16% of total wind additions in 2007 are owned by local electrical utilities, split between investor-owned utilities (IOUs) and publicly owned utilities (POUs) roughly two-to-one.19 Community wind power projects—defined here as projects using turbines over 50 kW in size and completely or partly owned by towns, schools, commercial customers, or farmers, but excluding publicly owned utilities—constitute the remaining 1% of 2007 projects. For offshore terms, this set of power producers may not be ideal since offshore wind farming involves large projects and a lot of infrastructure / project management which requires the backing of a large organisation.
 * 8.** Wind power sales prices are affected by a number of factors, two of the most important of which are installed project costs and project performance. In general, projects with higher installed costs also have higher wind power prices.//

//**Rf S2.2** // // **1. ** //// Offshore wind turbines have a number of **advantages** over onshore ones: - The size of onshore turbines is constrained by capacity limitations of the available transportation and erection equipment. Transportation and erection problems are mitigated offshore where the size and lifting capacities of marine shipping and handling equipment still exceed the installation requirements for multi-megawatt wind turbines. // // - Onshore, particularly in Europe or on the East Coast of the United States, the visual appearance of massive turbines in populated areas may be undesirable. At a sufficient distance from the coast, visual intrusion is minimized and wind turbines can be larger, thus increasing the overall installed capacity per unit area. - Less attention needs to be devoted to reduce turbine noise emissions offshore, which adds significant costs to onshore wind turbines. - The wind tends to blow faster and more uniformly at sea than on land. A higher, steadier wind means less wear on the turbine components and more electricity generated per square meter of swept rotor area. - Onshore turbines are often located in remote areas, where the electricity must be transmitted by relatively long power lines to densely populated regions, but offshore turbines can be located close to high-value urban load centers, simplifying transmission issues. - In Europe and the eastern United states, the amount of space available for offshore wind turbines is many times larger than for onshore ones. //

// On the **negative** side of offshore development: - Investment costs are higher and accessibility is more difficult, resulting in higher capital and maintenance costs. - Environmental conditions at sea are more severe: more corrosion from salt water and additional loads from waves and ice. // // - Offshore construction is more complicated. // // Despite the difficulties of offshore development, it holds great promise for expanding wind //// generation capacity. //

// ** 2. ** In the above table, up till 5NM is not included as an offshore wind reserve since this region mostly comprises of natural reserves. The 67% exclusion for 5-20NM away from shore is due to the fact that there are more avian, marine mammal, fish, and view shed concerns. For the zone from 20 nm to 50 nm, where there are fewer environmental concerns and wind farms are not visible, the exclusion was reduced to 33%, which again represents onshore experience for situations with moderate restrictions. All told, the areas between 5 nm and 50 nm off the coast of the United States contain about 907 GW of wind potential; an amount greater than current installed U.S. electrical capacity. // //3.// **// Present-day offshore wind power plants are located in very shallow water of 5m to 12 m. Turbine manufacturers have taken conventional land-based turbine designs, upgraded their electrical and corrosion control systems to marinize them, and placed them on concrete bases or steel monopiles to anchor them to the seabed. Offshore projects must be larger, in terms of both turbine size and project scale, to pay for the added turbine seabed support structures and cabling costs. In addition, turbine structural dynamics and fatigue loadings are much more complex and difficult to analyze offshore.
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 * 4.** Wind, wave, tide, and current conditions are less well defined in the Atlantic than for the shallower and more sheltered Baltic and North Seas. New wind and wave interaction models will need to be developed. As the offshore technology arrives in the United States, the wind energy will move towards to deeper water. This will mean more complex load applications and fatigue strength calculations. //

// Floating structures have already been successfully demonstrated by the marine and offshore oil industries. However, the technical requirements and economics are yet to be demonstrated for floating wind turbine platforms. The economics of deepwater wind turbines will be determined primarily by the additional cost of the floating structure and power distribution system. The floating structure must provide enough buoyancy to support the weight of the turbine and to restrain pitch, roll, and heave motions caused by the wind and wave forces. The oil and gas industry have characteristics similar to those being considered for floating wind turbine platforms, but their differences will allow the necessary cost reductions. // // • Oil platforms’ safety margins are higher to provide permanent residences for personnel. // // • Oil platforms must allow for personnel evacuation. Wind platforms are mostly unmanned. // // • Oil platforms must provide additional safety margins and stability for spill prevention. // // These are not concerns with wind platforms. // // • Wind platforms need only be deployed in water as deep as 600 ft. Floating oil tension leg // // platforms range in depths from 1500 ft to 8000 ft. // // • Wind turbine platforms can be submerged to minimize the structure exposed to wave loading. Oil platforms maximize above-water deck area and payload. // // In concise, deepwater wind turbines must take advantage of the in-depth experience of oil & gas in this field and work at arriving at the most economical design using the low cost experience of. 5. ** The Estimated Cost of Energy // // The approach for the cost study was to assume a nominal 500-MW wind plant composed of 100 machines, each with a 5-MW rating. Two platform concepts were used, as described by Musial and Butterfield ( Definition of a 5-MW Reference Wind Turbine for Offshore System Development). One was a concept developed by NREL; the other under a European study (Studie narr haalbaarheid van en randvoorwaarden voor drijvende offshore windturbines ECN, MARIN, Lagerwey the Windmaster, TNO, TUD, MSC, Dec. 2002). Costs were scaled over time with learning curves, which are typical of wind industry experience. These costs were compared to long-term cost expectations for shallow water. // //The cost estimates for shallow water technology, taken from a number of European offshore project papers, are provided in the Table below. These estimates are based on water shallower than 30 m, consistent with the deepest European experience. Foundations are based on steel monopile foundations. Because the turbines in this study are larger than those currently used in Europe (2- to 2.5-MW units), the foundation costs were scaled to match the increased loading for a 5-MW unit. The wind farm is 15-nm offshore, out of site from land. It is assumed to be a Class 6 wind site, which is consistent with the resource estimates described earlier. Cost projections have been made at 6 intervals from 2006 through 2025.// //Shallow Water Cost Estimates for Offshore Wind – Class 6 Winds// **
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// - Offshore conditions allow use of high tip-speed designs and reduced blade chord (reduce loads throughout the wind turbine structure) and reduce costs. Based on the WindPACT rotor study, these improvements can reduce the COE by as much as 15%. // // - In future the increased production volume shall result in improvements in manufacturing, assembly, and installation techniques, which in turn will lower the per-unit costs.Higher volumes mean costs from suppliers are also reduced. The International Energy Agency estimates that learning curve cost reductions for wind turbines are 18% per doubling of installed capacity. In a 2002 study Milborrow determined using worldwide production data that wind turbine prices have been declining at a rate of 15.3%. //

// NREL TLP Concept  Dutch Trifloater Concept **<span style="mso-bidi-font-family: TimesNewRoman; mso-ansi-language: EN-US; mso-ascii-font-family: Calibri; mso-ascii-theme-font: minor-latin; mso-hansi-font-family: Calibri; mso-hansi-theme-font: minor-latin;">  // <span style="mso-bidi-font-family: TimesNewRoman; mso-ansi-language: EN-US; mso-ascii-font-family: Calibri; mso-ascii-theme-font: minor-latin; mso-hansi-font-family: Calibri; mso-hansi-theme-font: minor-latin;"> <span style="mso-bidi-font-family: TimesNewRoman; mso-ansi-language: EN-US; mso-ascii-font-family: Calibri; mso-ascii-theme-font: minor-latin; mso-hansi-font-family: Calibri; mso-hansi-theme-font: minor-latin;">// To successfully achieve cost-competitive deepwater technologies, key collaborations must take place between three critical groups: // // 1) The oil and gas/marine industry // // 2) The present shallow water offshore wind energy industry // // 3) A targeted deepwater wind energy research community // // The first group possesses generations of experience in building and operating large structures and vessels at sea. Oil and gas companies have deployed thousands of offshore oil platforms. Demonstrably, the technology to make floating structures survive at sea under extreme conditions is understood. But these industries work under a different set of market constraints that involve a higher degree of human and environmental safety. The competitive wind energy markets need to redefine these technologies in terms of their own risk and reliability criteria specified by the wind energy experts. // // Thus, the second group will develop and transfer essential experience in offshore wind turbine operation that is directly applicable to deep water. These issues include O&M experience, safety and reliability specifications, turbine marinization, wind and wave interactions, array effects, permitting and ecological issues, and standardization models. Without question, many of these areas will have to be taken to a new level of sophistication for deepwater deployments, but the technical foundations will be formed through this shallow water experience. Without wind energy experience in shallow water, the risk to deepwater wind projects may be too great, and oil and gas cost drivers may result in noncompetitive pricing. // // The experience gained from the petroleum and the offshore wind industries together is // //essential—but not sufficient—to achieve cost-competitive deepwater wind energy in the next decade. Most countries that are actively engaged in the development of offshore wind, such as Denmark, Netherlands, and Germany, may be satisfied with shallow water technology for the near term, because the North Sea has an abundance of shallow water wind sites. **To activate the deepwater wind energy resource in the United States, a concerted R&D effort must be commissioned to address the issues specific to this technology, including dynamic modeling of the turbine and floating platform, floating platform optimization, low-cost mooring and anchor development, floating wind turbine COE optimization strategies, deepwater erection and decommissioning, standards governing floating wind turbines, deepwater resource assessment, and other specific deepwater concerns.** These relationships are shown below.
 * <span style="mso-bidi-font-family: 'TimesNewRoman,Bold'; mso-ansi-language: EN-US; mso-ascii-font-family: Calibri; mso-ascii-theme-font: minor-latin; mso-hansi-font-family: Calibri; mso-hansi-theme-font: minor-latin;">
 * <span style="mso-bidi-font-family: 'TimesNewRoman,Bold'; mso-ansi-language: EN-US; mso-ascii-font-family: Calibri; mso-ascii-theme-font: minor-latin; mso-hansi-font-family: Calibri; mso-hansi-theme-font: minor-latin;">// 6. Deepwater Research and Development Strategy // **
 * Summary**
 * 7.** Taking into account significant exclusions for shipping lanes, environmental easements, and view-shed concerns, areas off the coast of the United States, within a 50-nm limit, contain resources of almost 907 GW; an amount greater than current installed U.S. electrical capacity.// //Much of the offshore wind resource lies close to major// <span style="mso-bidi-font-family: TimesNewRoman; mso-ansi-language: EN-US; mso-ascii-font-family: Calibri; mso-ascii-theme-font: minor-latin; mso-hansi-font-family: Calibri; mso-hansi-theme-font: minor-latin;">// urban load centers with high-energy costs, and can be brought to market with minimal new // //transmission construction. With 98 GW of this resource located in waters shallower than 30m, a near-term market is available for the industry to gain experience and mature the technology.//

// **<span style="mso-bidi-font-family: TimesNewRoman; mso-ansi-language: EN-US; mso-ascii-font-family: Calibri; mso-ascii-theme-font: minor-latin; mso-hansi-font-family: Calibri; mso-hansi-theme-font: minor-latin;">9. **<span style="mso-bidi-font-family: TimesNewRoman; mso-ansi-language: EN-US; mso-ascii-font-family: Calibri; mso-ascii-theme-font: minor-latin; mso-hansi-font-family: Calibri; mso-hansi-theme-font: minor-latin;">New wind technology can be developed that could make floating wind turbines economical, at energy costs as low as $0.051/kWh in Class 6 winds by 2015, given sufficient volume production. <span style="mso-bidi-font-family: 'TimesNewRoman,Bold'; mso-ansi-language: EN-US; mso-ascii-font-family: Calibri; mso-ascii-theme-font: minor-latin; mso-hansi-font-family: Calibri; mso-hansi-theme-font: minor-latin;"> //
 * 8.** //Demonstrations that prove the viability and cost effectiveness of this new technology for largescale offshore applications will be critical to securing financing and insurance in the earlier stages. As the first projects are deployed over the next few years, the permitting process will become better defined and more streamlined to ensure that offshore wind projects are deployed with care and consideration to all ocean stakeholders without adding undue risk.//

//**Rf S2.3**

A site with homogeneous sand substrates may lend itself to a driven monopile foundation, whereas a shallow rock substrate may lend itself to a drilled and grouted monopile foundation. Typically, the latter would be significantly smaller in design and have lower procurement cost but its installation cost would be higher. Alternatively, a sandy substrate which offers poor load bearing, high mobility and/or obstruction risk may offer something close to a worst case scenario for foundation design. An important fact to be kept in mind while using this report as any base is the fact that this report was formed in 2003.//
 * 1) **// //The nature of the seabed and underlying substrates has been observed to be highly variable from project to project. It is also noted that it is not straightforward to deduce from a description of the substrate whether one site is more onerous or costly to construct than another. For example:
 * 2)** The foundation concept is available although it is not normally finalised until the construction contractor has been selected.
 * 3)** The voltage of the transmission line between wind farm and shore has been listed in the document. Although DC transmission exists as a proven engineering concept, all of the wind farms selected are likely to use conventional AC transmission.
 * 4)** Most projects use or plan to use boat access although technicians are landed by heli-hoist on the nacelles of turbines at Horns Rev and this is an option offered by most turbine manufacturers. GH consider that Horns Rev is a special case because it has a particularly long transit time by boat from the service port. In general, considerations of safety, cost and accessibility appear to be leading operators to use some form of boat access. To date, transfers of technicians from boat to turbine, which is the major access issue, have been by conventional ladder landings. However, the sites under construction and planned are mostly in more demanding wave climates and this method offers poor levels of safe accessibility. Hence, there are various different approaches under development to improve the access capability in bad weather. In terms of scheduling of O&M work, all offshore projects plan their main scheduled or preventative maintenance activities in the summer season when weather is more reliably benign. Winter O&M will mostly be unscheduled and undertaken as the sea state permits access. Therefore, the service function at an offshore wind farm will typically be more heavily resourced in summer than winter. For European projects, sea ice is only an issue in the Baltic Sea. This is mainly a design issue and the only project identified where specific measures have been taken for O&M work in Utgrunden, where the services of a small icebreaker are employed through the winter.
 * 5)** A total of 23 wind farm projects have been identified, with total capacity over 2000 MW, which have been constructed recently or which GH consider certain or likely to come into commercial operation in the next 2 to 3 years.


 * Rf S2.4** [[file:4 UK Offshore Wind.pdf]]