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On the way to 20MW wind turbine Written by Admins Last Updated: Wednesday, 08 June 2011 Enerģija un Pasaule (http://188.8.131.52) The UpWind research project has found that machines as large as 20 MW are feasible through developing a radical new design philosophy . Significant additional research efforts in wind energy are needed if the European Commission's goals for wind power are to be achieved. It will mean delivering EWEA's 'high' scenario: 265 GW of wind power capacity, including 55 GW offshore, by 2020; 400 GW, of which 150 GW is to come from offshore, by 2030; and 600 GW, with 350 GW offshore, by 2050, meeting 50% of the EU's electricity demand. Going offshore implies not only new technologies but also an upscaling of wind turbine dimensions and wind farm capacities as well as new electrical infrastructure. Underlying all research activities is a focus on reducing the cost of energy. The industry is taking two parallel pathways towards cost reduction: first, incremental innovation, looking at cost reductions through economies of scale resulting from increased market volumes of mainstream products, with a continuous improvement of manufacturing and installation methods and products; secondly, breakthrough innovation, focused on creating innovative products, including significantly upscaled dedicated offshore turbines, to be considered as new products. Funded under the European Union's Sixth Framework Programme (FP6), the UpWind project has been exploring both pathways. The UpWind project initiators realised that wind technology disciplines were rather fragmented, in that no integrated verified design methods were available; that essential knowledge was still missing in high priority areas, for example in external loads; that measuring equipment was still not accurate or fast enough; and that external factors were not taken into consideration in minimising cost of energy (grid connection, foundations, wind farm interaction and so on). Optimum Technology? Rather than pursue one single 'optimum' technology, UpWind explored various high-potential solutions and integrated them with a view to the potential reduction of cost of energy. An optimised wind turbine is the outcome of a complex function combining requirements in terms of efficiency of electricity production, reliability, access, transport and storage, installation, visibility, support to the electricity network, noise emission, cost, and so forth. UpWind's focus was the wind turbine as the essential component of a wind power plant. Thus external conditions were only investigated if the results were needed to optimise the turbine configuration. In Search of the 20 MW Wind Turbine UpWind established that 'the same, but bigger' would simply not work. Starting with a reference 5 MW wind turbine it initially extrapolated this reference design to upscale it to 10 MW, and then on to 20 MW. This virtual 20 MW design was unanimously assessed as almost impossible to manufacture, and uneconomic. It would weigh 880 tonnes on top of a tower making it impossible to store today at a standard dockside, or to install offshore with the current installation vessels and cranes. Powered by Elxis 2008.0 (Olympus). Copyright (C) 2006-2008 Elxis.org. All rights reserved. On the way to 20MW wind turbine Written by Admins Last Updated: Wednesday, 08 June 2011 Enerģija un Pasaule (http://184.108.40.206) The support structures able to carry such mass, placed at 153 metres height, are not possible to mass manufacture today. The blade length would exceed 120 metres, making it the world's largest ever manufactured composite element, which cannot be produced as a single piece with today's technologies. The blade wall thickness would also exceed 30 cm, which puts constraints on the heating of inner material core during the manufacturing process, and the blade length would also require new types of fibres in order to resist the loads. UpWind's 'Lighthouse' Approach to Methodology This 20 MW concept was drawn up to provide values and behaviour that could be a starting point for optimisation. UpWind then developed innovations to enable this basic design to be significantly improved, and therefore enable development of a potentially economically sound design. A means of doing this was adopting the lighthouse - a virtual concept design of a wind turbine in which promising innovations, either mature or embryonic, are incorporated. The lighthouse is not a pre-design of a wind turbine that will actually be realised, but a concept from which ideas can be drawn by industry for product development. One example is a blade made from thermoplastic materials, incorporating distributed blade control, including a control system, the input of which is partly fed by LIDARs. The 20 MW Innovative Turbine While the 20 MW design was unfeasible due to issues of weight and corresponding loads, the future large-scale wind turbine system drawn up by the UpWind project is smart, reliable, accessible, efficient and lightweight. It analysed wind turbine materials, optimising the micro-structure of blade materials to develop stronger and lighter blades. Fatigue loading also needed to be reduced so that longer and lighter blades may be built. And the aerodynamic and aeroelastic qualities of the models were significantly improved. Significant knowledge was gained on load mitigation and noise modelling. UpWind demonstrated that advanced blade designs could alleviate loads by 10%, by using more flexible materials and fore-bending the blades in the second work programme (WP). After reducing fatigue loads and applying materials with a lower mass to strength ratio, a third essential step is needed: the application of distributed aerodynamic blade control, requiring advanced blade concepts with integrated control features and aerodynamic devices. Fatigue loads could be reduced by 20%-40% (WP2). Various devices can be utilised to achieve this, such as trailing edge flaps, (continuous) camber control, synthetic jets, micro tabs, or flexible, controllable blade root coupling. Within UpWind, prototypes of adapting trailing edges, based on piezo-electrically deformable materials and SMA (shape memory alloys) were demonstrated (WP1B.3). However, the control system only works if both hardware and software are incorporated in the blade design. Thus advanced modelling and control algorithms need to be developed and applied. This was investigated in WP1B3. Powered by Elxis 2008.0 (Olympus). Copyright (C) 2006-2008 Elxis.org. All rights reserved. On the way to 20MW wind turbine Written by Admins Last Updated: Wednesday, 08 June 2011 Enerģija un Pasaule (http://220.127.116.11) Images: Powered by Elxis 2008.0 (Olympus). Copyright (C) 2006-2008 Elxis.org. All rights reserved.