Joint Assessment of Offshore Wind and Wave Energy Resources for the Portuguese Pilot Zone

2009 ◽  
Author(s):  
M. Teresa Pontes ◽  
Paulo Costa ◽  
Miguel Bruck ◽  
Anabela Carvalho
Keyword(s):  
Wave Energy ◽  
Wind Wave ◽  
Wave Model ◽  
Atmospheric Model ◽  
Energy Resources ◽  
Offshore Wind ◽  
Peak Period ◽  
Wave Conditions ◽  
Buoy Data ◽  
Joint Assessment

The objective of this paper is to present the joint assessment of offshore wind and wave energy resources for the Portuguese Wave Energy Pilot Zone (PZ). Offshore wind conditions are computed by the mesoscale regional atmospheric model MM5 whose good accuracy for that area had already been assessed through comparison against data. Wave conditions were produced by the shallow-water wind-wave model SWAN using as forcing wind the fields produced by MM5 and initial and boundary wave conditions computed the 3rd generation wind-wave model MAR3G. These preliminary results for the PZ were compared against buoy data for a two-month period. It was found that the accuracy is reasonable for significant wave height, wave power and mean direction but the energy period and peak period were significantly under-calculated. It is planned to further develop this work using initial and boundary conditions produced by a different wind-wave model as well as different SWAN parameterization models for wave generation and white-capping.

Assessing the Global Wave Energy Potential

2010 ◽  
Author(s):  
Gunnar Mo̸rk ◽  
Stephen Barstow ◽  
Alina Kabuth ◽  
M. Teresa Pontes
Keyword(s):  
Wave Energy ◽  
Wind Wave ◽  
Power Level ◽  
Wave Model ◽  
Altimeter Data ◽  
Second Step ◽  
Energy Potential ◽  
Satellite Altimeter ◽  
Buoy Data ◽  
Satellite Altimeter Data

In this paper the evaluation of the global wave energy potential is presented based on data from a global wind-wave model (validated and calibrated against satellite altimeter data) and buoy data (the WorldWaves database). The theoretical potential was computed first using all the available wave data and, in a second step, areas in which the power level is very low (P≤5kW/m) were excluded. Finally, in the third step, areas impacted by sea ice were removed. Annual and seasonal power distributions are presented both in tables and maps. The technical resource was also assessed for the west coast of Iberian peninsula showing a significant power decrease from north to south within only 500 km.

Numerical Prototyping of Floating Offshore Wind Turbines: Virtual Operation in Real Environmental Conditions

2020 ◽  
Author(s):  
Daniel Milano ◽  
Christophe Peyrard ◽  
Matteo Capaldo
Keyword(s):  
Wind Turbines ◽  
Wind Wave ◽  
Fatigue Analysis ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Wave Direction ◽  
Offshore Wind Turbines ◽  
Floating Offshore Wind Turbines ◽  
Wave Conditions

Abstract The numerical fatigue analysis of floating offshore wind turbines (FOWTs) must account for the environmental loading over a typical design life of 25 years, and the stochastic nature of wind and waves is represented by design load cases (DLCs). In this statistical approach, combinations of wind speeds and directions are associated with different sea states, commonly defined via simplified wave spectra (Pierson-Moskowitz, JONSWAP), and their probability of occurrence is identified based on past observations. However, little is known about the difference between discretizing the wind/wave direction bins into (e.g.) 10deg bins rather than 30deg bins, and the impact it has on FOWT analyses. In addition, there is an interest in identifying the parameters that best represent real sea states (significant wave height, peak period) and wind fields (profile, turbulence) in lumped load cases. In this context, the aim of this work is to better understand the uncertainties associated to wind/wave direction bin size and to the use of metocean parameters as opposed to real wind and sea state conditions. A computational model was developed in order to couple offshore wind turbine models with realistic numerical metocean models, referred to as numerical prototype due to the highly realistic wind/wave conditions in which it operates. This method allows the virtual installation of FOWTs anywhere within a considered spatial domain (e.g. the Mediterranean Sea or the North Sea) and their behaviour to be evaluated in measured wind and modelled wave conditions. The work presented in this paper compares the long-term dynamic behaviour of a tension-leg platform (TLP) FOWT design subject to the numerical prototype and to lumped load cases with different direction bin sizes. Different approaches to representing the wind filed are also investigated, and the modelling choices that have the greatest impact on the fidelity of lumped load cases are identified. The fatigue analysis suggests that 30deg direction bins are sufficient to reliably represent long-term wind/wave conditions, while the use of a constant surface roughness length (as suggested by the IEC standards) seems to significantly overestimate the cumulated damage on the tower of the FOWT.

Application of Data Assimilation for a Spectral Wave Model on Unstructured Meshes

2006 ◽  
Author(s):  
Tai-Wen Hsu ◽  
Shan-Hwei Ou ◽  
Jian-Ming Liau ◽  
Jaw-Guei Lin ◽  
Chia-Chuen Kao ◽  
...  
Keyword(s):  
Data Assimilation ◽  
Wind Wave ◽  
Wave Spectrum ◽  
Wave Model ◽  
Wave Period ◽  
Optimal Interpolation ◽  
Sequential Method ◽  
Significant Wave ◽  
Spectral Wave Model ◽  
Buoy Data

The effect of the data assimilation of buoy data in the wind wave model (WWM) for wind wave simulations in both deep and shallow water regions developed by Hsu et al. [2005] is investigated. Following Lionello et al. [1992], the sequential method is implemented, where analyzed wave spectra and significant wave fields were assimilated by optimal interpolation (OI), then the analyzed values were used to reconstruct the wave spectrum. This paper examines the results of the assimilation of wave spectrum, significant wave height and significant wave period in a nearshore WWM model. The WWM model underestimates the wave period because it incorrectly applies past wave field data. The analysis has provided useful indications of the shortcomings of the WWM model. In summary, the OI approach is shown to be a reliable assimilation scheme in the WWM model.

Joint Description Methods of Wind and Waves for the Design of Offshore Wind Turbines

2009 ◽  
Vol 43 (3) ◽  
pp. 23-33 ◽  
Author(s):  
Kim E. Mittendorf
Keyword(s):  
Wind Energy ◽  
Wind Wave ◽  
Limit State ◽  
Wave Model ◽  
Design Guidelines ◽  
Offshore Wind ◽  
Ultimate Limit State ◽  
Wave Loads ◽  
Offshore Wind Energy ◽  
The North

AbstractWind and wave loads are equally important for the design of offshore wind energy structures. For the design against an ultimate limit state or fatigue, the engineer has to estimate the combination of loads that are likely to occur simultaneously during the design life of the wind turbine. This is quite a complex task, involving different wind/wave models, load-calculation methods and statistical analysis of simultaneous extreme wind and wave conditions. Moreover, reliable and realistic methods for the assessment of the service life of an offshore wind energy converter under combined wind and wave loads are necessary. However, the current design guidelines (Det Norske Veritas or German Lloyd) provide hardly any information on how to model the wind and wave correlation. In this article, several approaches for obtaining the required wind-wave correlation for the design have been investigated. Manual wave forecasting methods, spectral sea state descriptions and numerical wave model data have been compared to simultaneously measured wind and wave data from the FINO research platform in the German Bight of the North Sea. The used approaches are general and can be easily applied to different data sets from different regions.

Joint Probability Distribution of Environmental Conditions for Design of Offshore Wind Turbines

2017 ◽  
Author(s):  
Jan-Tore H. Horn ◽  
Jørgen R. Krokstad ◽  
Jørgen Amdahl
Keyword(s):  
Wind Speed ◽  
Wind Turbines ◽  
Environmental Conditions ◽  
Wind Wave ◽  
Joint Probability ◽  
Offshore Wind ◽  
Joint Probability Distribution ◽  
Peak Period ◽  
Offshore Wind Turbines ◽  
Mean Wind Speed

The design process for offshore wind turbines includes a fatigue life evaluation of the structure with the relevant environmental conditions at the specified wind farm location. Such analyses require long-term distributions of the environmental parameters including their correlation. In general, the significant wave height, wave peak period and mean wind speed are the most important parameters for describing offshore environmental conditions. However, due to the low side-to-side damping level of offshore bottom-fixed wind turbines, wave directions misaligned with the wind direction may excite low-damped vibrational modes. As a consequence, the accumulated fatigue damage in the wind turbine foundation may change, compared to collinear wind and waves. In the current work, an extension to the three-parameter environmental joint probability distribution is presented, with the resulting distribution being a function of the significant wave height, peak period of the total sea, mean wind speed and the wave directional offset compared to the mean wind heading i.e. the wind-wave misalignment. The sea states within a 1-year return period for Dogger Bank are presented, as well as the 10- and 50-year environmental contour lines and extreme wind-wave misalignment angles.

scholarly journals Floating Offshore Renewable Energy Farms. A Life-Cycle Cost Analysis at Brindisi, Italy

Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 6150
Author(s):  
Daniela Pantusa ◽  
Antonio Francone ◽  
Giuseppe Roberto Tomasicchio
Keyword(s):  
Renewable Energy ◽  
Life Cycle ◽  
Hybrid System ◽  
Wave Energy ◽  
Life Cycle Cost ◽  
Wind Wave ◽  
Wind Farms ◽  
Offshore Wind ◽  
Floating Platforms ◽  
System Coupling

The present paper deals with the Life-Cycle Cost (LCC) of an offshore renewable energy farm that is currently a topic of interest for operators and investors. The LCC analysis refers to the Cost Breakdown Structure (CBS) considering all the phases of life span, and it has been carried out for floating offshore wind farms (FOWFs) and hybrid wind-wave farms (HWWFs). For HWWFs, this paper proposes a hybrid wind-wave energy system (HWWES), which provides the coupling of wave energy converter (WEC) with Tension Leg Platform (TLP) or Spar Buoy platform (SB). The LCC analysis has been carried out considering: (i) FOWF consisting of TLP floating platforms; (ii) FOWF consisting of a SB floating platforms; (iii) HWWF realized with the conceived hybrid system coupling the WEC with the TLP platform; (iv) HWWF realized with the conceived hybrid system coupling the WEC with SB platform. In addition to the LCC evaluation, the Levelized Cost of Energy (LCOE) analysis has also been carried out. The site chosen for the study is off the port of Brindisi, southern Italy. This work’s interest lies in having performed a LCC analysis for FOWF and HWWF in the Mediterranean that is an area of growing interest for offshore renewable energy, and obtained results have allowed making assessments on costs for offshore energy farms.

scholarly journals Joint Environmental Data at Five European Offshore Sites for Design of Combined Wind and Wave Energy Devices

2013 ◽  
Author(s):  
Lin Li ◽  
Zhen Gao ◽  
Torgeir Moan
Keyword(s):  
Renewable Energy ◽  
Deep Water ◽  
Wave Energy ◽  
Environmental Data ◽  
Energy Resources ◽  
Offshore Wind ◽  
Wave Power ◽  
Joint Distributions ◽  
Wave Parameters

The costs for an offshore wind farm, especially with bottom fixed foundations increase significantly with increasing water depth. If costs can be reduced to a competitive level, the potential for wind farms in deep water is huge. One way of reducing costs might be to combine offshore wind with wave energy facilities at sites where these resources are concentrated. In order to design combined renewable energy concepts, it is important to choose sites where both wind and wave energy resources are substantial. Such facilities might be designed in ultimate limit states based on load effects corresponding to 50-year wind and wave conditions. This requires a long-term joint probabilistic model for the wind and wave parameters at potential sites. In this paper, five European offshore sites are selected for analysis and comparison of combined renewable energy concepts developed in the EU FP7 project – MARINA Platform. The five sites cover both shallow water (<100m) and deep water (> 200m), with three sites facing the Atlantic Ocean and the other two sites in the North Sea. The selection of the sites is carried out by considering average wind and wave energy resources, as well as extreme environmental conditions which indicate the cost of the system. Long-term joint distributions of mean wind speed at 10-meter height (Uw), significant wave height (Hs) and spectral peak period (Tp) are presented for selected sites. Simultaneous hourly wind and wave hindcast data from 2001–2010 are used as a database, which are obtained from the National and Kapodistrian University of Athens. The joint distributions are estimated by fitting analytical distributions to the hindcast data following a procedure suggested by Johannessen et al. (2001). The long-term joint distributions can be used to estimate the wind and wave power output from each combined concept, and to estimate the fatigue lifetime of the structure. For estimation of the wind and wave power separately, the marginal distributions of wind and wave are also provided. Based on the joint distributions, contour surfaces are established for combined wind and wave parameters for which the probability of exceedance corresponds to a return period of 50 years. The design points on the 50-year contour surfaces are suggested for extreme response analysis of combined concepts. The analytical long-term distributions established could also be applied for design analysis of other offshore structures with similar environmental considerations of these sites.

scholarly journals An atmosphere–wave regional coupled model: improving predictions of wave heights and surface winds in the southern North Sea

Ocean Science ◽  
2017 ◽  
Vol 13 (2) ◽  
pp. 289-301 ◽  
Author(s):  
Kathrin Wahle ◽  
Joanna Staneva ◽  
Wolfgang Koch ◽  
Luciana Fenoglio-Marc ◽  
Ha T. M. Ho-Hagemann ◽  
...  
Keyword(s):  
North Sea ◽  
German Bight ◽  
Wind Wave ◽  
Surface Wind ◽  
Wave Model ◽  
Atmospheric Model ◽  
Induced Drag ◽  
Wave Heights ◽  
Wave Induced ◽  
The Impact

Abstract. The coupling of models is a commonly used approach when addressing the complex interactions between different components of earth systems. We demonstrate that this approach can result in a reduction of errors in wave forecasting, especially in dynamically complicated coastal ocean areas, such as the southern part of the North Sea – the German Bight. Here, we study the effects of coupling of an atmospheric model (COSMO) and a wind wave model (WAM), which is enabled by implementing wave-induced drag in the atmospheric model. The numerical simulations use a regional North Sea coupled wave–atmosphere model as well as a nested-grid high-resolution German Bight wave model. Using one atmospheric and two wind wave models simultaneously allows for study of the individual and combined effects of two-way coupling and grid resolution. This approach proved to be particularly important under severe storm conditions as the German Bight is a very shallow and dynamically complex coastal area exposed to storm floods. The two-way coupling leads to a reduction of both surface wind speeds and simulated wave heights. In this study, the sensitivity of atmospheric parameters, such as wind speed and atmospheric pressure, to the wave-induced drag, in particular under storm conditions, and the impact of two-way coupling on the wave model performance, is quantified. Comparisons between data from in situ and satellite altimeter observations indicate that two-way coupling improves the simulation of wind and wave parameters of the model and justify its implementation for both operational and climate simulations.

scholarly journals An Evaluation of the Wind and Wave Dynamics along the European Coasts

2019 ◽  
Vol 7 (2) ◽  
pp. 43 ◽  
Author(s):  
Daniel Ganea ◽  
Elena Mereuta ◽  
Eugen Rusu
Keyword(s):  
Wave Model ◽  
Atmospheric Model ◽  
Reference Points ◽  
Global Perspective ◽  
Weather Forecasts ◽  
Wave Dynamics ◽  
The Mean ◽  
Wave Conditions ◽  
Geographical Locations ◽  
European Seas

The objective of this work is to analyze the wind and wave conditions along the coasts of the European seas. The emphasis is put on the mean and maximum values. The areas studied are characterized by intense maritime activities, including traffic, as well as various harbor and offshore operations. In the present study, 35 years of data (1983–2017) coming from the European Centre for Medium-Range Weather Forecasts (ECMWF) were processed, corresponding to 40 different geographical locations. Thus, these 40 reference points are defined for some of the most relevant offshore locations in the coastal environments targeted. As regards the data considered in the analysis, two different sets were used. The first corresponds to the wave model, while the second to the atmospheric model, both operated by ECMWF. Finally, it can be concluded that the proposed work provides a global perspective related to the average and maximum wind and wave conditions and to a further extent on the climate dynamics along the coasts of the European seas.

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