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- Category: Articles
Anemometry Technology to Measure the Wind in Front of the Rotor
The ROMO Wind iSpin system uses proven ultrasonic technology to measure wind where it first hits the turbine – directly at the spinner. In this way, it is able to measure parameters at the nacelle which until now have been difficult or impossible to measure accurately. Operators gather exact information on the wind conditions in front of the rotor including wind speed, yaw alignment, flow inclination, turbulence, rotor position and temperature. This enables them to check whether their turbines are aligned for the best possible yield. At the same time, the data allows for optimised wind farm management and load reduction, which prolongs the total life of the turbines.
By Harald Hohlen, ROMO Wind Deutschland GmbH, Germany
- Category: Articles
The Integrated Urban Green Wind Energy Solution
PowerNEST is a new sustainable energy generation system for the tops of buildings. IBIS Power and Pontis Engineering have joined forces to get PowerNEST to a state where it is ready to enter the European market. The consortium has received a Horizon 2020 SME Phase II grant from the EC and is now fully operational and ready to realise the first demonstration in the Netherlands within a few months. The initial stage of the overall European project consists of installing 25 units within 2 years, therefore gaining sufficient knowledge to develop a standardised mass production design and establish a distribution network. The EU independent review committee awarded a score of 14.35 out of 15.00 to the project with all aspects graded as ‘excellent’.
By Anna Blanch Vergés and Dr Alexander B. Suma, IBIS Power, The Netherlands
- Category: Articles
A Few Potential Design Alternatives and System-level Reassessment
In recent years, increasing evidence of failures has been reported from spherical roller main bearings used in three-point mounting (TPM) drivetrains of wind turbines. One of the leading causes has been micropitting, a failure mode that is possibly overlooked by design, selection and life-prediction tools. It remains to be seen if retrofitting problematic spherical roller bearings (SRBs) with improved bearing design solutions can improve their durability. Questions to ask might be: ‘Are the operating conditions of the main bearing well understood?’ and ‘Are the failures caused by deficient design practice or other unidentified external sources within the system?’ These questions fundamentally challenge the underlying design basis and encourage the need for a system analysis approach that is currently being undertaken by researchers from the National Renewable Energy Laboratory (NREL). Specifically, this article discusses a few potential design alternatives and system-level reassessment to circumvent micropitting in main bearings used in TPM drivetrains.
By Latha Sethuraman, Yi Guo and Shuangwen Sheng, National Wind Technology Center, National Renewable Energy Laboratory, USA
- Category: Articles
Development of a Collision Risk Model
The US Fish and Wildlife Service (FWS), in conjunction with the US Geological Survey and Washington State University, have developed a statistical model that enables a wind facility to predict its expected number of bird fatalities in advance of construction. Avian fatalities at wind facilities are a serious consideration for both wildlife and wind facility managers. Many local, regional and international laws protect various bird species, making an understanding of a facility’s potential impact invaluable for planning and conservation purposes.
By Dr Leslie New, Washington State University, Vancouver, USA
- Category: Articles
The Effect on the Bottom Line
One of the most difficult jobs facing project managers tasked with the mobilisation of critical resources in the renewables industry is planning ahead for what are often referred to as medium range weather impacted events. Forecasting weather over longer periods (typically up to 15 days in advance, often termed medium range forecasts) is extremely difficult to predict with any degree of accuracy due to the volatile and chaotic nature of the atmosphere. Very small variations in the initial conditions of a computer forecast model can lead to huge variations in the forecast – a phenomenon known as the ‘Butterfly Effect’. This is why forecasters can typically only forecast conditions up to roughly three days ahead with any degree of precision. Beyond this timescale, conditions become significantly more influenced by these tiny initial variations.
By Polly Kirk, Regional Marketing Executive, MeteoGroup, UK
- Category: Articles
A Crane-Less Solution for Great Heights
Concrete towers have become an increasingly popular choice in the wind industry around the world because of their superior ability to support larger turbines at higher hub heights. However, this market is being constrained when it comes to increasing tower height because of the limited availability of the powerful cranes needed to erect such tall towers.
By Ramón López Mendizábal, Director, Esteyco, Spain
- Category: Articles
Optimising Aerodynamic Efficiency at the Wind Farm Design Stage
Reduced wind turbine performance, as compared to the manufacturer’s design or warranted power curve, is common outside of the turbine design conditions. On many sites, such as those with steep slopes or considerable forestry, or simply those that experience certain atmospheric conditions, turbines will regularly operate outside the ideal operational conditions without falling outside the operational envelope. This typically results in reduced wind turbine performance and can have a major impact on overall project performance. Prevailing has applied established angle of attack based aerodynamic theories to produce a method of modelling the aerodynamic efficiency of a wind turbine for supplied wind conditions. The presented methodology can be used to provide turbine performance predictions. Accurate turbine performance predictions contribute to better wind farms both by optimising turbine layouts and providing improved preconstruction energy yield estimates.
By Alex Head, Prevailing Analysis, USA and Joel Manning, Prevailing Analysis, UK
