Conference programme

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Delegates are invited to meet and discuss with the poster presenters during the poster presentation sessions between 10:30-11:30 and 16:00-17:00 on Thursday, 19 November 2015.

Lead Session Chair:
Stephan Barth, ForWind - Center for Wind Energy Research, Germany
Guillem Juncà Farreras GE Renewable Energy, Spain
Guillem Juncà Farreras (1) F
(1) Alstom Wind, Barcelona, Spain

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Presenter's biography

Biographies are supplied directly by presenters at EWEA 2015 and are published here unedited

Mr. Guillem Juncà Farreras has been working in the wind industry for around 3 years. He is currently holding the position of Site Specific Assessment Engineer in ALSTOM Wind. He studied mechanical engineering at the Polytechnic University of Catalonia in Barcelona. He started his career during the later years of his studies in the Loads and Aerodynamics department of ALSTOM Wind. His areas of expertise are wind turbine loads and structural dynamics.


Poster Download poster (9.57 MB)


Optimization Platform for Site Specific Loads Assessment


An optimization platform for site specific loads assessment is presented.


OPAL (Optimization Platform for the Assessment of Loads) provides a link between the resource assessment, wind farm design and the site suitability assessment. It is oriented to be part of a general layout optimization process, providing a fast and automatic answer to the loads suitability problem.

Main body of abstract

OPAL has a modular design conceived to provide flexibility in terms of input data format and calculation models. The input data consists on a fixed layout and the corresponding external conditions at each position. These external conditions can be defined with different levels of detail, ranging from representative values (IEC-class like) to more accurate predictions taking into account directionality and seasonality. Different wind turbine models can be considered, each with a different surrogated model and different input/output format. Loads oriented wake models are implemented feeding on free-flow data. The standard approach of a surrogated model is a fatigue loads database. These databases are created for specific aeroelastic models, using thousands of simulations covering a wide range of external conditions. The tool obtains design equivalent load and load duration distribution outputs for every fatigue design load case by interpolating between the stored results. This allows easily combining different situations over the turbine’s lifetime: specific external conditions depending on wind direction and season, turbine operation strategies, wakes, etc. Surrogated models are created and tested for certified wind turbine models. When wake effects lead to higher loads than the acceptable values, sector management strategies can be defined. These strategies include curtailment and/or power limitation of either the wake-generating or wake-receiving turbine, depending on the situation. Even though the fatigue loads are calculated individually, the sector management strategies affect the wake interaction scenario. Thus, the definition of sector management strategies becomes an iterative process involving the whole wind farm. In order to minimize the impact of the sector management on the production, an optimization algorithm is implemented. These two aspects make the surrogate model an essential part of the process, since the loads are evaluated hundreds of times during the optimization.


The platform can be used as a consultation tool that determines whether a wind farm layout design is suitable in terms of loads, and what strategies need to be applied. It can also serve as a more detailed loads analysis tool. This allows to determine which are the most loaded components, what are the possible causes (site conditions, wakes, etc.), and point to potential solutions.

Learning objectives
OPAL is a first step into an integrated wind farm layout optimization tool that minimizes cost of energy for every site.