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- Category: Articles
Enhancing Reliability and Reducing LCOE of Drive-Trains
Advances in design, materials and drive-train testing have resulted in substantial improvements of wind turbine reliability, particularly in the 2–4MW class [1]. But with continuous growth in size of turbines, the risk of gearbox damage appears to be back on the agenda. Further upscaling of conventional drive-train designs is limited and alternative architectures might be required. A flexible element at the low-speed shaft allows the gearbox to be mounted rigidly to the main frame and relieves the gearbox from unnecessary stress and fatigue. The author of this article was part of a team that recently presented the results of a load study of such a system [2]. The focus of the current article is on a commercial study with the objective to identify the potential of reducing operational cost (OPEX) and enhancing levelised cost of energy (LCOE), using the example of a 6MW offshore wind turbine.
By Alexander Kari, Geislinger GmbH, Austria
- Category: Articles
Fog Shows Amazing Details over North Sea Wind Farm
On 25 January 2016 at 12:45 UTC several photographs of the offshore wind farm Horns Rev 2 were taken by helicopter pilot Gitte Lundorff with an iPhone. A very shallow layer of fog covered the sea. The photos of the fog over the sea dramatically pictured the offshore wind farm wake. Researchers got together to investigate the atmospheric conditions at the time of the photos by analysing local meteorological observations and wind turbine information, satellite remote sensing and nearby radiosonde data. Two wake models and one mesoscale model were used to model the case and explain what was seen.
By Charlotte Bay Hasager, Ioanna Karagali, Patrick Volker and Søren Juhl Andersen Technical University of Denmark, Denmark and Nicolai Gayle Nygaard, DONG Energy, Denmark
- Category: Articles
Virtual Wind Farm Simulation
The WakeBlaster project team was formed in January 2017 and is an interdisciplinary team of six dedicated scientists, software engineers, expert computer modellers and wind industry professionals. Together the team has over 55 years of experience in the wind industry. Its mission is to produce a cloud-based software component which delivers down-to-earth, cost-effective, scalable and dynamic yet accurate wind farm simulations.
By Dr Wolfgang Schlez, Director of ProPlanEn, UK
- Category: Articles
Use of Lidars to Quantify Flow and Wind Turbine Wakes
Wind turbine nameplate capacities (and physical dimensions) are increasing and turbines are being deployed in increasingly complex/harsh environments. Hence, shortcomings are becoming evident in our understanding of the flow parameters of relevance to wind resources and turbine loading in inhomogeneous settings. Furthermore, propagation and dissipation of wakes from turbines on ridges and/or on escarpments and/or when flow interacts with vegetation are incompletely understood. While model predictions of the mean and time-evolving components of flow may be imperfect in simple topography, model errors tend to be relatively small. However, systematic and non-trivial model biases can exist in complex terrain. Hence there is a need for full-scale experiments using remote sensing technologies (notably lidars) to quantify key flow characteristics and provide data that can be used in model development and evaluation. Here we describe some key research opportunities and challenges facing these experimental investigations and present results from our recent field campaigns.
By Rebecca J. Barthelmie and Sara C. Pryor, Cornell University, USA
- Category: Articles
The Differences between Measured and Predicted Noise Levels from Wind Farms
When planning a new wind farm, it is essential to obtain a reliable estimate of the future noise impact. An underestimation of the noise impact can lead to complaints and subsequent possible loss of efficiency due to mitigation schemes like a temporary shutdown or the use of curtailment strategies. On the other hand, an overestimation of the noise impact leads to an underdevelopment of the wind park potential.
By Luc Schillemans, Tractebel, Belgium
- Category: Articles
Exploring New Technologies for Extreme-Scale Turbines
Larger turbines – beyond today’s multi-megawatt onshore and offshore machines – are one of the most attractive options for reducing the cost of wind energy. Continued technology scale-up to rated capacities of 10MW and beyond requires novel concepts for overcoming the fundamental limitations of today’s turbine designs and materials, including structural constraints of drive-train components. This article explores how magnetic gearbox technologies could provide solutions.
By Luis Cerezo, Technical Executive, EPRI, USA
- Category: Articles
How to Calculate the Remaining Useful Life (RUL) of Wind Farms
Wind farms are part of our surroundings and therefore are in general fairly accessible power generation facilities. Safety is key to both continuation of operations and a corporate responsibility towards workers and third parties. It must be safeguarded through a comprehensive process including analytical RUL calculation, inspections and certification to confirm that there is a limited risk exposure while the installation continues operating. Once the real status of the wind turbines is characterised, smart operational strategies can be deployed to maximise the return on the investment.
By Jose Javier Ripa, Business Development Manager, UL DEWI, Spain
