Intelligent Airborne Inspection

Providing Quality Assurance Over the Lifetime

Aero Enterprise fig 1The standard inspection method for quality assurance of the exterior surfaces of wind turbines is to employ people trained as rope access or industrial climbers. But this is not the only way. This article, by Robert Hörmann of Aero Enterprise in Austria, outlines (using his company’s products) how drones can undertake visual inspection of turbines, and then supporting software and archiving can be used to analyse the data. As the author admits, drones and airborne access will never be a complete substitute for manned inspection, and there will always be the need for rope access workers, but he shows that there are many advantages to drone-based inspection together with software analysis and archiving.

By Robert Hörmann, CEO/CTO and Founder of Aero Enterprise, Austria

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Precast Braced Foundations

Towards a Significant CoE Reduction

Esteyco Figure 1The auction system is leading to reductions in the price of energy worldwide. At present every competitor involved in the sector is focusing on maximising energy production while trying to minimise the investment needed for this purpose. One of the trends is the use of higher towers and more powerful turbines. This leads to an increase of foundation loads, and hence higher volumes of concrete on regular shallow slab foundations. Nowadays values around 400–450 cubic metres of concrete per wind turbine generator (WTG) foundation are common and therefore efforts are being made to reduce both this concrete volume and the amount of reinforcing steel in the WTG foundations. So far, most of the innovative solutions have not had a significant penetration into the market since although there were material savings there were also much higher execution costs as well as longer construction schedules.

By Ramón López Mendizabal, Esteyco Energía, Spain

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Extending the Life of Gearboxes and Bearings

 

Rewitec 1a Rewitec 1b  

The Use of Nano- and Micro-sized Particle-Based Lubricant Additives

Nano- and micro-sized particle-based lubricant additives are used in wind turbine applications, and also in engines, gears and bearings in different industry sectors such as cement, steel, mining, maritime and automotive around the world. Treated machinery, gearboxes and bearings can run better with reduced friction and temperature and greater reliability and durability due to reduced abrasion and wear. Rewitec is an independent, medium-sized business that develops such additives, and in this article its Managing Director Stefan Bill describes how the company’s products have undergone tribological tests and been shown to provide life extension upgrades.

By Stefan Bill, Rewitec, Germany

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Remote Sensing in Cold Climates

Vaisala Oct fig 1Proven Practices for Optimal Results

Onshore wind farm developers are increasingly looking to cold climate regions around the globe for various reasons, including the strength of the available resource and low population density. However, carrying out high-quality measurement campaigns in cold climates poses a number of unique challenges for developers.

By Juha Paldanius and Nihat Hunerli, Vaisala, Hamburg, Germany

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Innovative Blade Tips for Wind Turbines

ECN 1What do Shark Fins, Winglets and Turbulators Have in Common?

Ambitions and developments in offshore wind energy have forced us to re-evaluate our approach and methods in wind turbine blade design once more. With the ultimate goal of reducing the levelised cost of energy (LCoE) through optimised tip design, the InnoTip research project ran as a collaboration between LM Wind Power’s aerodynamics team and ECN. During this project three new tip designs were delivered and two were tested by extending the blades on ECN’s 2.5MW test turbines with a temporary add-on tip extension – a unique process.

By Ozlem Ceyhan Yilmaz, ECN, The Netherlands and Jordy van Kalken, LM Wind Power, Denmark

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Composite Low-Speed Shaft Coupling

Geislinger Figure 1 onder elkaarEnhancing 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

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Wind Farm Wake

Hasager et al WindTech Figure1Fog 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

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