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Sample records for nysted havmoellepark baggrundsrapport

  1. Offshore wind farms in the local community - a survey at Nysted offshore wind farm. Background report; Havvindmoeller i lokalomraedet - en undersoegelse ved Nysted havmoellepark. Baggrundsrapport

    Energy Technology Data Exchange (ETDEWEB)

    Kuehn, S.

    2005-07-15

    This report is part of a socio-economic project about offshore wind farms' influence on the local community. The project is part of the monitoring programme in connection with the establishment of the offshore wind farms at Horns Rev and Nysted. The socio-economic project consists of a sociological and an environment-economic project. This report is part of the sociological project which has the purpose of identifying attitudes towards the wind farm before and after the erection with a view to identify possible changes in opinions and reasons for these changes. (BA)

  2. Offshore wind farms in the local community - a survey at Horns Rev wind farm. Background report; Havvindmoeller i lokalomraedet - en undersoegelse ved Horns Rev havmoellepark. Baggrundsrapport

    Energy Technology Data Exchange (ETDEWEB)

    Kuehn, S.

    2005-07-15

    This report is part of a socio-economic project about offshore wind farms' influence on the local community. The project is part of the monitoring programme in connection with the establishment of the offshore wind farms at Horns Rev and Nysted. The socio-economic project consists of a sociological and an environment-economic project. This report is part of the sociological project which has the purpose of identifying attitudes towards the wind farm before and after the erection with a view to identify possible changes in opinions and reasons for these changes. (BA)

  3. Spatio-temporal correction targeting Nysted Offshore. Probabilistic forecasts

    DEFF Research Database (Denmark)

    Tastu, Julija; Pinson, Pierre; Trombe, Pierre-Julien

    This report concerns probabilistic forecasts for Nysted Offshore. Different approaches for issuing predictive densities are studied, discussed in details and compared. The results show that the spatial correction of the first order moments of the predictive densities improves the quality of the c......This report concerns probabilistic forecasts for Nysted Offshore. Different approaches for issuing predictive densities are studied, discussed in details and compared. The results show that the spatial correction of the first order moments of the predictive densities improves the quality...... of the corresponding forecasts. The spatial correction of the higher order moments is shown to be unnecessary as does not bring any additional amelioration. The best performing of the studied models is based on the adaptive quantile regression using the spatially corrected point predictions as input. This model...

  4. Offshore wind farms in the local environment - an examination at Horns Rev Offshore Wind Farm. Background report; Havvindmoeller i lokalomraadet - en undersoegelse ved Horns Rev Havmoellepark. Baggrundsrapport

    Energy Technology Data Exchange (ETDEWEB)

    Kuehn, Susanne

    2005-07-01

    Horns Rev Offshore Wind Farm was built in 2002. A presentation is made of a sociological, qualitative survey on the local community's reception of the offshore wind farm. The survey aims at identifying attitudes towards the farm before and after the construction, with a view to identifying possible changes in attitudes, and explain the reasons for these (ml)

  5. Sociological investigation of the reception of Nysted Offshore wind farm. Annual report 2004[Denmark

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-08-15

    This annual report presents the work related to the sociological part of a socio-economic project that examines the effects on the local communities of the two demonstration off-shore wind farms: Horns Rev Offshore Wind Farm, west of Blaavands Huk in Jutland, and Nysted Offshore Wind Farm, south of Lolland. The socio-economic project is part of the monitoring programme in connection with the construction of the offshore wind farms. Unlike projects, which examine the impact of the wind farms on nature, the socio-economic project did not start until 2003. The other part of the socio-economic project is an environmental-economic study that among other things examines the preferences of the population in relation to location of the wind farm and the willingness to pay for increasing the distance between the wind farms and the coast. This sociological study is qualitative. The study is divided into three phases, as the aim is to investigate the public community's attitude towards the erection of an offshore wind farm before and after the construction of the wind farm. This aim is based on the assumption that attitudes may change once the wind farm is erected and the population has experienced the visibility of the wind farm, etc. The division into phases is as follows: 1) Phase 1 treats the conditions as they were before the erection of Nysted Offshore Wind Farm. 2) Phase 2 is a study of the development in attitudes towards Horns Rev Offshore Wind Farm a year after erection. 3) Phase 3 comprises a follow-up study of the local area at Nysted Offshore Wind Farm. The Horns Rev study was conclusive and was carried out September-November 2003. The study at Nysted on the other hand implies two parts. The first was carried out April-August 2003 and identified attitudes before the wind farm was completed. A follow-up study in August-December 2004 served the purpose of revealing the extent of attitude changes regarding the wind farm and the development of these changes of

  6. Evaluation of wind farm efficiency and wind turbine wakes at the Nysted offshore wind farm

    DEFF Research Database (Denmark)

    Barthelmie, Rebecca Jane; Jensen, L.E.

    2010-01-01

    Here, we quantify relationships between wind farm efficiency and wind speed, direction, turbulence and atmospheric stability using power output from the large offshore wind farm at Nysted in Denmark. Wake losses are, as expected, most strongly related to wind speed variations through the turbine...... be quantified, albeit with relatively large uncertainty due to stochastic effects in the data. There is evidence of the ‘deep array effect’ in that wake losses in the centre of the wind farm are under-estimated by the wind farm model WAsP, although overall efficiency of the wind farm is well predicted due...... thrust coefficient; with direction, atmospheric stability and turbulence as important second order effects. While the wind farm efficiency is highly dependent on the distribution of wind speeds and wind direction, it is shown that the impact of turbine spacing on wake losses and turbine efficiency can...

  7. Sociological investigation of the reception of Horns Rev and Nysted offshore wind farms in the local communities[Denmark

    Energy Technology Data Exchange (ETDEWEB)

    Kuehn, S.

    2005-03-15

    This annual report presents the work related to the sociological part of the socio-economic project on the local communities' reception of the Horns Rev Offshore Wind Farm, west of Blaavands Huk in Jutland, and the Nysted Offshore Wind Farm, south of Lolland. The project is part of the monitoring programme in connection with the construction of the offshore wind farms. Unlike projects, which examine the impact of the wind farms on nature, the socio-economic project did not start until 2003. The socio-economic project examines the effects on the local communities. Among other things the environmental-economic part of the project examines the preferences of the population in relation to location of the wind farm and the willingness to pay for increasing the distance between the wind farms and the coast. The sociological survey is qualitative. The survey is divided into three phases, as the aim is to investigate the public community's attitude towards the erection of an offshore wind farm before and after the construction of the wind farm. This aim is based on the assumption that attitudes may change once the wind farm is erected and the population has experienced the visibility of the wind farm, etc. The division into phases is as follows: 1) Phase 1 treats the conditions as they were before the erection of Nysted Offshore Wind Farm. 2) Phase 2 is an investigation of the development in attitudes towards Horns Rev Offshore Wind Farm a year after erection. 3) Phase 3 comprises a follow-up investigation of the local area at Nysted Offshore Wind Farm. This annual report treats phases 1 and 2. Phase 1 was carried out in April-August 2003, and the interviews at Nysted were thus made during the erection of the first offshore wind turbines. Phase 2 was carried out in September-November 2003. The follow-up investigation of the conditions in the local area around Nysted offshore wind farm is to be carried out in August-December 2004. The results of the investigations

  8. Review report 2004. The Danish offshore wind farm demonstration project: Horns Rev and Nysted offshore wind farms. Environmental impact assessment and monitoring

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-10-15

    The present review report presents the two wind farms Horns Rev and Nysted with regard to environmental characteristics and the results of the environmental studies carried out in connection with the Environmental Impact Assessment (EIA) and the baseline and monitoring programmes at the two sites. The descriptions of the programmes are based on extracts from the individual annual reports. Detailed information on method, programmes and conclusions can be found in these reports (see Appendix 1). This review report is divided into two parts. The first part contains a description of the potential environmental impacts of offshore wind farms and the potentially affected part of the environment. The second part includes a description of Horns Rev and Nysted Offshore Wind Farm and the environmental studies carried out here until the end of 2003. Appendix I is a list of the literature published on the studies carried out at Horns Rev and Nysted Offshore Wind Farm. Appendix II is a list of some of the literature relevant to the demonstration projects but not directly related to the projects. The offshore wind farm situated in the Roedsand area is officially denoted Nysted Offshore Wind Farm, and in the present report the denotation 'Nysted' will be used as well when referring to Nysted Offshore Wind Farm. The denotation Roedsand will be used when referring to the actual area Roedsand. (au)

  9. Comparison of Measured Transient Overvoltages in the Collection Grid of Nysted Offshore Wind Farm with EMT Simulations

    DEFF Research Database (Denmark)

    Arana Aristi, Iván; Holbøll, Joachim; Sørensen, T.

    2009-01-01

    This paper presents a comparison between GPS synchronized measurements of two switching operations in Nysted Offshore Wind Farm (NOWF) in Denmark, and results from electromagnetic transient (emt) simulations of these switching events using Power Factory/DIgSILENT and PSCAD/EMTDC. The collection...... grid of Nysted created in Power Factory and PSCAD was based on the information available from the wind farm as-built documentation. The cable model used in both programs was created based on the geometry and material properties of the cable. Circuit breakers and transformers were modelled by means...... of the comparable simple standard models in both tools. The results from the simulations in Power Factory and PSCAD match the measured steep fronted first wave, when one radial is energized in the wind farm. However, differences were found in both simulation tools results compared with the measurements, in the more...

  10. Regulation models for district heating. Background report; Denmark; Reguleringsmodeller for fjernvarmen. Baggrundsrapport

    Energy Technology Data Exchange (ETDEWEB)

    2012-02-15

    The background report describes in detail the elements of the analysis: the present regulation, experiences from other countries and sectors, the aim of regulation, and detailed analysis of four regulation models. (LN)

  11. Integrated environment and energy management; Integreret miljoe- og energiledelse - erfaringer fra 11 virksomheder - Baggrundsrapport

    Energy Technology Data Exchange (ETDEWEB)

    Pommer, Kirsten [Teknologisk Inst., Taastrup (Denmark)

    2005-07-01

    The report collects experiences from 11 companies from different sectors. The companies have during the past few years been working with integration of environment and energy management. the report forms background for the booklet 'Spar penge pae miljoe og energi - slae to fluer med et smaek'. (BA)

  12. Summarizing background report for Energy Strategy 2025; Sammenfattende baggrundsrapport for Energistrategi 2025

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-06-01

    The Danish Government's long-term energy strategy follows up on the political agreement of 29 March 2004. The energy strategy is a coherent formulation of the Government's long-term energy policy. The pivotal point for the energy strategy is liberalized energy markets and market based tools for obtaining goals such as efficiency, security of supply and environment. The focus is increasingly on the substantial business potential within development of new and more efficient energy technology, in which Denmark takes up several globally strong positions. Furthermore, transportation energy consumption has been included directly in an energy strategy for the first time. At the same time as the energy strategy is presented, a summarizing background report from the Danish Energy Agency with facts, analyses and evaluations is published, as well as a report from energinet.dk that summarizes the system responsibilities' input to that part of the energy strategy that deals with power infrastructure. (BA)

  13. Conditions for coastal wind turbines and small-scale wind farms; Rammer for kystnaere havmoeller og mindre havmoelleparker

    Energy Technology Data Exchange (ETDEWEB)

    2011-04-15

    The coastal wind turbine report recommends that research and demonstration projects be prioritised when determining the placement of 400 MW of coastal wind turbines in the coming years. Much of the capacity, however, is expected to be allotted to production wind turbines. A study will be carried out to identify the coastal areas best suited for the placement of wind turbines. Construction of offshore wind farms will be put out to tender in order to ensure that the best project is chosen at the lowest price. (ENS)

  14. Large-scale offshore wind farms in Denmark. Update of ''Future offshore sites for wind turbines 2025''; Stor-skala havmoelleparker i Danmark. Opdatering af fremtidens havmoelleplaceringer

    Energy Technology Data Exchange (ETDEWEB)

    2011-04-15

    This updating of the ''Future offshore sites for wind turbines 2025'', is made by the Offshore Wind Farm Committee and adjusts primarily the existing sites in relation to a updated data basis. The sites are adjusted within the already identified areas, and no new areas are therefore included. In addition to an update of the underlying data base, including the revised sailing routes, the new Natura 2000 sites and mineral resources, there are now further collected knowledge about the seabed in the designated areas. Moreover, the underlying assumptions for construction costs and grid connection updated, which has resulted in a revised socio-economic priority of the areas. The Offshore Wind Farm Committee's report confirms that the placement of the 600 MW Kriegers Flak Offshore Wind Farm in the Baltic Sea is the best location for Denmark's next major offshore wind farm. Kriegers Flak Offshore Wind Farm is already included in the Government's energy strategy. (LN)

  15. Analysis on the furthering of competition in relation to the establishment of large off-shore wind farms in Denmark. Main report; Analyse vedroerende fremme af konkurrence ved etablering af store havmoelleparker i Danmark. Hovedrapport

    Energy Technology Data Exchange (ETDEWEB)

    Joergensen, Carsten; Enevoldsen, M. (Deloitte, Copenhagen (Denmark))

    2011-04-15

    The report, based on the 2010 tender for Anholt Offshore Wind Farm, is an analysis of how competition in the offshore wind power area can be increased, and a lower consumer price achieved. The study concludes that there is broad support for the Danish tender model among relevant parties, just as the process of working with Danish authorities and connecting to the power grid were viewed positively by potential investors in Danish offshore wind farms. But the report also found that inflexible guidelines in the Anholt Offshore Wind Farm tender contributed to a higher settlement price. One example singled out by the report was the threat of drastic fines and short deadlines. Moreover, the tender also occurred at a time when the production of wind turbines and foundations could not keep pace with increasing demand, particularly in Germany and the United Kingdom. Deloitte forecasts that the price for building and operating offshore wind farms, despite the increasing demand for offshore wind turbines, can be cut by between 25% and 30% by 2020, given the right framework guidelines and tender conditions. Applied to the planned Kriegers Flak Offshore Wind Farm, this calculation would result in a settlement price of between DKK 0.781 and DKK 0.979/kWh. The settlement price for Anholt Offshore Wind farm is currently DKK 1.051/kWh. The report recommends that the tender be altered to permit a greater dialogue with potential bidders, and to allow for information about the tenders to be spread internationally. Deloitte's report is based on interviews with individuals from a number of energy companies, investors, and public agencies, and takes into account other countries' experiences building offshore wind farms, as well as an evaluation of the competitive conditions within the offshore wind sector. (ENS)

  16. Perspectives for the Danish heat supply towards 2025. Technical background report to the Energy Strategy 2025; Perspektiver for den danske varmeforsyning frem mod 2025. Teknisk baggrundsrapport til Energistrategi 2025

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-06-01

    This report describes the economy within different heating systems today and in 2025. A number of focus areas are addressed: 1) joint supply in the future, 2) phasing out of oil for individual heating, and 3) the possibilities for limiting/making effective the power consumption for heating. Special attention is paid to single-family houses, in which a considerable part of the energy consumption for heating is used. Though the report doesn't provide a complete picture of the Danish heat supply, the calculations can form basis for an estimate of the probable trend for Danish heat supply towards 2025. This probable trend forms background for projections of the energy consumption of heating in dwellings, which enters into the joint projections, manufactured in connection with the Energy Strategy 2025. (BA)

  17. Antimicrobial and Controlled Release Studies of a Novel Nystatin Conjugated Iron Oxide Nanocomposite

    Directory of Open Access Journals (Sweden)

    Samer Hasan Hussein-Al-Ali

    2014-01-01

    Full Text Available Nystatin is a tetraene diene polyene antibiotic showing a broad spectrum of antifungal activity. In the present study, we prepared a nystatin nanocomposite (Nyst-CS-MNP by loading nystatin (Nyst on chitosan (CS coated magnetic nanoparticles (MNPs. The magnetic nanocomposites were characterized by X-ray powder diffraction (XRD, Fourier transform infrared spectroscopy (FT-IR, thermogravimetry analysis (TGA, vibrating sample magnetometer (VSM, and scanning electron microscopy (SEM. The XRD results showed that the MNPs and nanocomposite are pure magnetite. The FTIR analysis confirmed the binding of CS on the surface of the MNPs and also the loading of Nyst in the nanocomposite. The Nyst drug loading was estimated using UV-Vis instrumentation and showing a 14.9% loading in the nanocomposite. The TEM size image of the MNPs, CS-MNP, and Nyst-CS-MNP was 13, 11, and 8 nm, respectively. The release profile of the Nyst drug from the nanocomposite followed a pseudo-second-order kinetic model. The antimicrobial activity of the as-synthesized Nyst and Nyst-CS-MNP nanocomposite was evaluated using an agar diffusion method and showed enhanced antifungal activity against Candida albicans. In this manner, this study introduces a novel nanocomposite that can decrease fungus activity on-demand for numerous medical applications.

  18. Hydrogen for transport in Denmark towards 2050. Contribution to electric-powered transport, growth, CO{sub 2} reduction and independence of fossil fuels; Brint til transport i Danmark frem mod 2050. Bidrag til elektrisk transport, vaekst, CO{sub 2} reduktion og fossil uafhaengighed. Baggrundsrapport. Endelig udgave

    Energy Technology Data Exchange (ETDEWEB)

    Wennike, F. (Hydrogen Link Danmark (Denmark)); Mortensgaard, A. (Brint and Braendselscelle Partnerskabet, Copenhagen (Denmark)); Sloth, M. (H2 Logic A/S, Herning (Denmark))

    2011-12-15

    Significant funding has been invested internationally in the development of hydrogen and fuel cells for the last 10 years, among others by the leading car makers. In Denmark alone businesses have, along with contributions from public programs, invested two billion DKK since 2001. The investments have helped to develop and mature hydrogen and fuel cells so that a deployment can be initiated from 2015. With the Danish government's new initiative, ''Our Energy'', which is targeted towards a switch to a fossil fuel-independent society in 2050, it is obvious that hydrogen is included as one of many technologies that can help solve the challenge within the transport sector. The Hydrogen Link Denmark Association and selected Danish players in the Hydrogen and Fuel Cell Partnership in Denmark has therefore prepared this analysis which describes a possible contribution to electrical transport, growth, CO{sub 2} reduction and fossil fuel independence by introduction of hydrogen for transport in Denmark up to 2050. The analysis is based on a possible share of hydrogen cars in the Danish car fleet in 2050 of 50% and the secondary effects of activation of the energy policy objectives for fossil fuel independence, and not least the significant potential for Danish exports of hydrogen and fuel cell technology and affected jobs. Similarly, the contribution of hydrogen for transport in relation to balancing the increased share of fluctuating renewable energy production was analyzed. (LN)

  19. Quantifying the Impact of Wind Turbine Wakes on Power Output at Offshore Wind Farms

    DEFF Research Database (Denmark)

    Barthelmie, Rebecca Jane; Pryor, Sara; Frandsen, Sten Tronæs;

    2010-01-01

    . Detailed data ensembles of power losses due to wakes at the large wind farms at Nysted and Horns Rev are presented and analyzed. Differences in turbine spacing (10.5 versus 7 rotor diameters) are not differentiable in wake-related power losses from the two wind farms. This is partly due to the high...... to an unacceptably high degree of uncertainty....

  20. Een merkwaardige Lamium maculatum L

    NARCIS (Netherlands)

    Mennema, J.

    1968-01-01

    Lamium X cardiaca Cogniaux, found before 1815 in Belgium near Kanne by Nyst, and considered by its author to be the hybrid of Lamium maculatum and Leonurus cardiaca, falls within the variability of L maculatum L. It has also been found in the Netherlands between Mook and Middelaar (prov. Limburg) an

  1. Interseismic and coseismic surface deformation deduced from space geodetic observations : with inferences on seismic hazard, tectonic processes, earthquake complexity, and slip distribution

    NARCIS (Netherlands)

    Bos, A.G. (Annemarie Gerredina)

    2003-01-01

    In this thesis I am concerned with modeling the kinematics of surface deformation using space geodetic observations in order to advance insight in both interseismic and coseismic surface response. To model the surface deformation field I adopt the method of Spakman and Nyst (2002) which resolves the

  2. Validation of the dynamic wake meander model with focus on tower loads

    DEFF Research Database (Denmark)

    Larsen, Torben J.; Larsen, Gunner Chr.; Pedersen, Mads Mølgaard

    2017-01-01

    of wind speeds. In general, tower loads in wake conditions are very challenging to predict correctly in simulations. The Nysted project offers an improved insight to this field as six wind turbines located in the Nysted II wind farm have been instrumented to measure tower top and tower bottom moments. All...... a period extending over a time span of more than 3 years. Based on the recorded data basic mechanisms driving the increased loading experienced by wind turbines operating in offshore wind farm conditions have been identified, characterized and modeled. The modeling is based on the Dynamic Wake Meandering...... (DWM) approach in combination with the state-of-the-art aeroelastic model HAWC2, and has previously as well as in this study shown good agreement with the measurements. The conclusions from the study have several parts. In general the tower bending and yaw loads show a good agreement between...

  3. Summary Report: The Shadow effect of large wind farms: measurements, data analysis and modelling

    DEFF Research Database (Denmark)

    Frandsen, Sten Tronæs; Barthelmie, Rebecca Jane; Rathmann, Ole;

    It was the goal of the project – by means of data from the demonstration wind farms Horns Rev and Nysted, analyses of these data and modelling – to facilitate prediction of the power losses from a wind farm should a new wind farm be built upwind relative to the prevailing wind direction. Or conve......It was the goal of the project – by means of data from the demonstration wind farms Horns Rev and Nysted, analyses of these data and modelling – to facilitate prediction of the power losses from a wind farm should a new wind farm be built upwind relative to the prevailing wind direction....... The databases – one for each site – include production and operational statistics for the wind turbines and statistics for the meteorological measurements carries out in the vicinity of the wind farms. Several different modelling activities were carried out, which intentionally to some extent are redundant...

  4. PSO-Ensemble Demo Application

    DEFF Research Database (Denmark)

    2004-01-01

    Within the framework of the PSO-Ensemble project (FU2101) a demo application has been created. The application use ECMWF ensemble forecasts. Two instances of the application are running; one for Nysted Offshore and one for the total production (except Horns Rev) in the Eltra area. The output...... is available via two password-protected web-pages hosted at IMM and is used daily by Elsam and E2....

  5. PSO-Ensemble Demo Application

    DEFF Research Database (Denmark)

    2004-01-01

    Within the framework of the PSO-Ensemble project (FU2101) a demo application has been created. The application use ECMWF ensemble forecasts. Two instances of the application are running; one for Nysted Offshore and one for the total production (except Horns Rev) in the Eltra area. The output is a...... is available via two password-protected web-pages hosted at IMM and is used daily by Elsam and E2....

  6. Wind farm related mortality among avian migrants - a remote sensing study and model analysis

    DEFF Research Database (Denmark)

    Desholm, M.

    ,136 migrating sea ducks only 47 individuals were predicted to collide with the wind turbine rotor-blades, equivalent to an overall mean collision risk of c. 0.02%. This thesis shows the added value of modelling in supplementing sound empirical studies in accessing the effects of major human development......-2006) of migrating birds at the Nysted offshore wind farm in the Baltic Sea, Denmark. This thesis poses and answers the following questions: a) what hazard factors do offshore wind farming pose to wild birds, b) how should one choose the key focal species to study, c) how can remote sensing techniques be applied...

  7. Mesoscale wind fluctuations over Danish waters

    DEFF Research Database (Denmark)

    Vincent, Claire Louise

    - Horns Rev I in the North Sea, and Nysted in the Baltic Sea. The thesis begins with a climatological analysis of wind uctuations on time scales of 1{10 hours at the two sites. A novel method for calculating conditional climatologies of spectral information is proposed, based on binning and averaging...... the time axis of the Hilbert spectrum. Results reveal clear patterns between wind uctuations and locally observed meteorological conditions. The analysis is expanded by classifying wind uctuations on time scales of 1{3 hours according to synoptic patterns, satellite pictures and wind classes. Results...

  8. Effects on harbour porpoises from Roedsand 2 Off-shore Wind Farm

    Energy Technology Data Exchange (ETDEWEB)

    Teilmann, J.; Tougaard, J.; Carstensen, J.

    2012-11-15

    E.ON Vind Sverige has been commissioned the construction of Roedsand 2 Offshore Wind Farm comprising 90 wind turbines, south of Lolland-Falster, Denmark. The location of the wind farm is 3 km west of the existing Nysted Offshore Wind Farm with 72 turbines. In combination the two wind farms represents the largest wind farm area in the world. Porpoises were monitored by automatic acoustic dataloggers (T-PODs) according to a statistical BACI design and deployed during baseline (Sep 2008-Feb 2009) and during operation (Sep 2011-Mar 2012). These instruments were deployed at 10 stations covering a coastal stretch of 35 km from Gedser to Roedby, including the wind farm area with reference areas on both sides. In addition, background noise at four of the T-POD stations was recorded by automatic noise loggers. In order to assess the potential cumulative effect of two adjacent wind farms, similar data from the Nysted Offshore Wind Farm were also analysed. We found no overall change in echolocation activity over the entire monitoring area from baseline to operation of Roedsand 2 Offshore Wind Farm. Also, there was no significant change in the echolocation activity in Roedsand 2 Offshore Wind Farm relative to each or a combination of the three reference areas, i.e. changes from baseline to operation were similar in the impact and reference areas. Also no significant change in noise levels audible to porpoises was found. This could be due to a generally high noise level in the area, masking the turbine noise or that the noise loggers in the wind farm were deployed between the wind turbines, i.e. at distances {approx}350-450 m from the turbines. This study also shows that the echolocation activity is still significantly lower in Nysted Offshore Wind Farm since the baseline in 2001-2002, although the difference seem to gradually diminish possibly due to a habituation of the porpoises to the wind farm or better feeding posibilities. We found no cumulative effect of the two wind

  9. Transient Model Validation of Fixed-Speed Induction Generator Using Wind Farm Measurements

    DEFF Research Database (Denmark)

    Rogdakis, Georgios; Garcia-Valle, Rodrigo; Arana Aristi, Iván

    2012-01-01

    In this paper, an electromagnetic transient model for fixed-speed wind turbines equipped with induction generators is developed and implemented in PSCAD/EMTDC. The model is comprised by: an induction generator, aerodynamic rotor, and a two-mass representation of the shaft system. Model validation...... is conducted by measurement comparison using recordings obtained from switching operations performed at the Nysted OffshoreWind Farm in Denmark. A sensitivity analysis is performed to determine the impact of different model parameters on the simulated response as compared with measurements. This validated...

  10. Disease: H00776 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available H00776 Congenital motor nystagmus (CMN); Idiopathic congenital nystagmus (ICN) Nyst...ndependent of these known ocular or systemic diseases is referred to as congenital motor nystagmus (CMN) or idiopathic congenital...ulsi EI, Munier FL Novel mutations in FRMD7 in X-linked congenital nystagmus. Mutation in brief #963. Online.... Hum Mutat 28:525 (2007) PMID:22065086 Xiao X, Li S, Guo X, Zhang Q A novel locus for autosomal dominant congenital... Chinese family with X-linked congenital nystagmus. Mol Vis 17:715-22 (2011) ...

  11. Statistical meandering wake model and its application to yaw-angle optimisation of wind farms

    Science.gov (United States)

    Thøgersen, E.; Tranberg, B.; Herp, J.; Greiner, M.

    2017-05-01

    The wake produced by a wind turbine is dynamically meandering and of rather narrow nature. Only when looking at large time averages, the wake appears to be static and rather broad, and is then well described by simple engineering models like the Jensen wake model (JWM). We generalise the latter deterministic models to a statistical meandering wake model (SMWM), where a random directional deflection is assigned to a narrow wake in such a way that on average it resembles a broad Jensen wake. In a second step, the model is further generalised to wind-farm level, where the deflections of the multiple wakes are treated as independently and identically distributed random variables. When carefully calibrated to the Nysted wind farm, the ensemble average of the statistical model produces the same wind-direction dependence of the power efficiency as obtained from the standard Jensen model. Upon using the JWM to perform a yaw-angle optimisation of wind-farm power output, we find an optimisation gain of 6.7% for the Nysted wind farm when compared to zero yaw angles and averaged over all wind directions. When applying the obtained JWM-based optimised yaw angles to the SMWM, the ensemble-averaged gain is calculated to be 7.5%. This outcome indicates the possible operational robustness of an optimised yaw control for real-life wind farms.

  12. Economic valuation of the visual externalities of off-shore wind farms

    Energy Technology Data Exchange (ETDEWEB)

    Ladenburg, J.; Dubgaard, A.; Martensen, L.; Tranberg, J.

    2005-07-01

    The study is based on a mail survey including 700 households in a national sample, and 350 households in two sub samples in the Horns Rev and Nysted areas. In the choice experiment, four alternative off-shore wind farm distances from the coast were used namely: 8, 12, 18 and 50 km. Based on the respondents' choices between alternative locations of off-shore wind farms their willingness to pay (WTP) for increasing the distance was elicited using three different sub samples for each of the three locations. These sub samples were constructed using the full sample (B-model), a sample containing respondents who were certain in their choice (C-model) and finally a sample containing respondents, who according to a defined set of questions were considered consistent and rational in their choice (R-model). (au)

  13. The color of interval

    CERN Multimedia

    Nyst,JL

    1983-01-01

    J.L.Nyst a étudié aux Beaux Arts de Madrid et Liège et a participé à de nombreux expositions en Belgique, son pays, et à l'étranger. Sa conférence est sous le titre "la couleur de l'intervalle" et il passera une bande vidéo avec intermèdes musicaux qui s'appelle "Theresa Plane", qui vient d'obtenir le prix spécial de biopraphie à l'actuelle exposition internationale d'art vidéo. Il a crée un cours d'art vidéo à l'Académie de Beaux Arts de Liège où il enseigne.

  14. Cross-spectra over the sea from observations and mesoscale modelling

    DEFF Research Database (Denmark)

    Vincent, Claire Louise; Larsén, Xiaoli Guo; Larsen, Søren Ejling

    2013-01-01

    Cospectra and quadrature spectra are calculated for six pairs of tall offshore measurement masts near the Horns Rev I wind farm in the Danish North Sea and the Nysted wind farm in the Baltic sea. The mast-pairs are separated from one another by horizontal distances of 2.13–12.4 km. Cospectra...... based on 3-month simulations using the weather research and forecasting (WRF) numerical model with a horizontal grid spacing of 2 km. For the sea-fetch directions, good agreement in spectral properties between the model and observations is found. Analytical expressions based on the properties...... of the cross-correlation function and an exponentially decaying coherence function are fitted to the normalized cospectra and quadrature spectra. The expressions are shown to be a good fit to the spectra calculated from the WRF simulations and to the observed spectra for directions with a long sea-fetch, which...

  15. Energy Dynamics of an Infinitely Large Offshore Wind Farm

    DEFF Research Database (Denmark)

    Frandsen, Sten Tronæs; Barthelmie, R.J.; Pryor, S.C.

    , particularly in the near-term, can be expected in the higher resource, moderate water depths of the North Sea rather than the Mediterranean. There should therefore be significant interest in understanding the energy dynamics of the infinitely large wind farm – how wakes behave and whether the extraction...... of energy by wind turbines over a large area has a significant and lasting impact on the atmospheric boundary layer. Here we focus on developing understanding of the infinite wind farm through a combination of theoretical considerations, data analysis and modeling. Initial evaluation of power losses due...... to wakes in the large Danish offshore wind farms at Horns Rev and Nysted indicated that losses were larger than expected. Temporary solutions have been found to account for this in wind farm models including use of an ‘added roughness’ block around the offshore wind farm. In the long-term however physical...

  16. Phasor Measurement Units in the Eastern Danish power system

    DEFF Research Database (Denmark)

    Nielsen, Arne Hejde; Pedersen, Knud Ole Helgesen; Jørgensen, Preben;

    2006-01-01

    Technology. After power system events data can be extracted and analyzed offline. The purpose of the project is to do research within various utilizations of PMU data. On 8 January 2005 a severe storm passed Denmark, and wind speeds were so high, that wind turbines disconnected from the transmission grid......In the Eastern Danish transmission system four Phasor Measurement Units (PMU’s) are installed at 400 kV and 132 kV voltage level. The PMU’s continuously record voltage and current phasors each 20 ms. Data are stored locally on the PMU’s and are also transferred to a database at Centre for Electric...... because of their self protection. Nysted offshore wind farm was among the wind power units that disconnected from the grid, and PMU data from that event are analyzed. The case illustrates the close relation between voltages, power flows and voltage phase angles over a wide area. The voltage phase angle...

  17. Phasor Measurement Units in the Eastern Danish power system

    DEFF Research Database (Denmark)

    Nielsen, Arne Hejde; Pedersen, Knud Ole Helgesen; Jørgensen, Preben

    2006-01-01

    In the Eastern Danish transmission system four Phasor Measurement Units (PMU’s) are installed at 400 kV and 132 kV voltage level. The PMU’s continuously record voltage and current phasors each 20 ms. Data are stored locally on the PMU’s and are also transferred to a database at Centre for Electric...... because of their self protection. Nysted offshore wind farm was among the wind power units that disconnected from the grid, and PMU data from that event are analyzed. The case illustrates the close relation between voltages, power flows and voltage phase angles over a wide area. The voltage phase angle...... measurements complements the traditional voltage and power flow measurements....

  18. ARIMA-Based Time Series Model of Stochastic Wind Power Generation

    DEFF Research Database (Denmark)

    Chen, Peiyuan; Pedersen, Troels; Bak-Jensen, Birgitte

    2010-01-01

    This paper proposes a stochastic wind power model based on an autoregressive integrated moving average (ARIMA) process. The model takes into account the nonstationarity and physical limits of stochastic wind power generation. The model is constructed based on wind power measurement of one year from...... the Nysted offshore wind farm in Denmark. The proposed limited-ARIMA (LARIMA) model introduces a limiter and characterizes the stochastic wind power generation by mean level, temporal correlation and driving noise. The model is validated against the measurement in terms of temporal correlation...... and probability distribution. The LARIMA model outperforms a first-order transition matrix based discrete Markov model in terms of temporal correlation, probability distribution and model parameter number. The proposed LARIMA model is further extended to include the monthly variation of the stochastic wind power...

  19. Voltage dip caused by the sequential energization of wind turbine transformers

    DEFF Research Database (Denmark)

    Arana Aristi, Iván; Holbøll, Joachim; Sørensen, T.

    2009-01-01

    THIS paper presents the results from electromagnetic transient (emt) simulations using PSCAD, where the model of Nysted Offshore Wind Farm (NOWF) was created to simulate the voltage dips due to wind turbine transformer energization. Four different sequences energizing different numbers of wind...... turbine. The step up transformer (2,5 MVA, 33/0.69 kV) in every turbine is connected via a switch-disconnector and fuse on the MV-side. The grid codes are defined by the Transmission System Operator of each country, and some of them are not updated to regulate correctly the operation of large wind power...... plants. According to the British Engineering Recommendations P28, the voltage fluctuation at the point of connection with the grid may be required to be as low as 3% during the energization of a motor; and since the energization of a transformer is similar to the direct-on-line starting of induction...

  20. Coseismic slip distribution of the 1923 Kanto earthquake, Japan

    Science.gov (United States)

    Pollitz, F.F.; Nyst, M.; Nishimura, T.; Thatcher, W.

    2005-01-01

    The slip distribution associated with the 1923 M = 7.9 Kanto, Japan, earthquake is reexamined in light of new data and modeling. We utilize a combination of first-order triangulation, second-order triangulation, and leveling data in order to constrain the coseismic deformation. The second-order triangulation data, which have not been utilized in previous studies of 1923 coseismic deformation, are associated with only slightly smaller errors than the first-order triangulation data and expand the available triangulation data set by about a factor of 10. Interpretation of these data in terms of uniform-slip models in a companion study by Nyst et al. shows that a model involving uniform coseismic slip on two distinct rupture planes explains the data very well and matches or exceeds the fit obtained by previous studies, even one which involved distributed slip. Using the geometry of the Nyst et al. two-plane slip model, we perform inversions of the same geodetic data set for distributed slip. Our preferred model of distributed slip on the Philippine Sea plate interface has a moment magnitude of 7.86. We find slip maxima of ???8-9 m beneath Odawara and ???7-8 m beneath the Miura peninsula, with a roughly 2:1 ratio of strike-slip to dip-slip motion, in agreement with a previous study. However, the Miura slip maximum is imaged as a more broadly extended feature in our study, with the high-slip region continuing from the Miura peninsula to the southern Boso peninsula region. The second-order triangulation data provide good evidence for ???3 m right-lateral strike slip on a 35-km-long splay structure occupying the volume between the upper surface of the descending Philippine Sea plate and the southern Boso peninsula. Copyright 2005 by the American Geophysical Union.

  1. The shadow effect of large wind farms: measurements, data analysis and modelling. Summary report[Final summary report

    Energy Technology Data Exchange (ETDEWEB)

    Frandsen, Steen; Barthelmie, R.; Rathmann, O.; Joergensen, Hans E.; Badger, J.; Hansen, Kurt; Ott, S.; Rethore, P.-E.; Larsen, Soeren E.; Jensen, Leo E.

    2007-07-15

    It was the goal of the project by means of data from the demonstration wind farms Horns Rev and Nysted, analyses of these data and modelling to facilitate prediction of the power losses from a wind farm should a new wind farm be built upwind relative to the prevailing wind direction. Or conversely, predict with adequate accuracy the production of a new wind farm built downwind of an existing wind farm. The project should be seen in the perspective of the two existing demonstration wind farms that extend 5-10 km in each direction. In order to e.g. use the existing electrical infrastructure it may be appropriate to build new wind farms rather close to the existing wind farms. A relevant question is therefore how far away new wind farms must be placed to avoid too large power losses. Measurements have been carried out for several years at the two sites, and databases have been prepared. The databases one for each site include production and operational statistics for the wind turbines and statistics for the meteorological measurements carries out in the vicinity of the wind farms. Several different modelling activities were carried out, which intentionally to some extent are redundant. Thus, if different modelling efforts results in comparable results, the quality of the models will be tested outside the physical range where data are available. All project participants find that the project has been immensely successful. The main achievements of the project are: 1) Measurements were carried out at the Nysted and Horns Rev demonstration wind farms for several years. Doing so included design, installation and operation of the measurement system 2) A data base was built from the incoming data. The data have been organized to facilitate verification of the models developed as part of the project 3) 6-7 different models have been developed and compared. 4) Approximately 20 journal and conference papers have resulted directly from the project (au)

  2. Collision risks at sea: species composition and altitude distributions of birds in Danish offshore wind farms

    Energy Technology Data Exchange (ETDEWEB)

    Blew, J.; Hoffmann, M.; Nehls, G. [BioConsult SH (Germany)

    2007-07-01

    This study investigates the collision risks of birds in operating offshore wind farms, focussing on all bird species present in the direct vicinity of the wind farms, their altitude distribution and reactions. The project was conducted jointly by BioConsult SH and the University of Hamburg in the two Danish offshore wind farms Horns Rev (North Sea) and Nysted (Baltic Sea) in the framework of a Danish-German cooperation and financed by the German Federal Ministry for the Environment, Nature Conservation and Nuclear Safety (BMU). Data were collected between March 2005 and November 2006, using a ship anchored at the edge of the offshore wind farms. In this way, bird species of all sizes could be considered. Daytime observations yielded data on species composition, flight routes and potential reactions of the birds. Radar observations provided altitude distributions inside and outside the wind farm area and also reactions. The results shall help to further describe and assess the collision risk of different species groups. Since data analysis is still running, exemplary results will be presented here. 114 species have been recorded in Nysted and 99 in Horns Rev, approximately 65% of which have been observed inside the wind farm areas. Migrating birds seem to avoid flying into the wind farms, whereas individuals present in the areas for extended time periods utilize areas within the wind farms. While a barrier effect exists for species on migration, resident species probably have a higher collision risk. Raptors migrating during daylight frequently enter the wind farm area on their flight routes, correcting their flight paths in order to avoid collisions. Radar results show that during times of intensive migration, the proportion of birds flying at high altitudes and thus above windmill height is higher than in times of low migration intensity. Consequently, there is a lower proportion of migrating birds flying within the risk area. Data will be further analysed to

  3. Wind farm related mortality among avian migrants - a remote sensing study and model analysis

    Energy Technology Data Exchange (ETDEWEB)

    Desholm, M.

    2006-11-15

    This thesis is the result of a PhD study on bird-wind farm collisions and consists of a synopsis, five published papers, one submitted manuscript and another ready for submission. The papers describe the findings from pre- and post-construction visual, radar and thermal imaging studies (1999-2006) of migrating birds at the Nysted offshore wind farm in the Baltic Sea, Denmark. This thesis poses and answers the following questions: a) what hazard factors do offshore wind farming pose to wild birds, b) how should one choose the key focal species to study, c) how can remote sensing techniques be applied to the study of bird wind farm interactions, and d) specifically, how do water birds react when approaching an offshore wind farm? The main aim of the study was the development of a predictive bird-wind farm collision model that incorporates the avoidance rate of birds at multiple scales. Out of 235,136 migrating sea ducks only 47 individuals were predicted to collide with the wind turbine rotor-blades, equivalent to an overall mean collision risk of c. 0.02%. This thesis shows the added value of modelling in supplementing sound empirical studies in accessing the effects of major human development pressures on migratory bird populations. (au)

  4. Wind farm power optimization including flow variability

    DEFF Research Database (Denmark)

    Herp, Jürgen; Poulsen, Uffe Vestergaard; Greiner, Martin

    2015-01-01

    an optimized wind-farm control strategy, derived from a fixed wake parameter, is facing this flow variability, the potential gain reduces to 0.3–0.5%. An omnipotent control strategy, which has real-time knowledge of the actual wake flow, would be able to increase the gain in wind-farm power to 4.9%.......A model-based optimisation approach is used to investigate the potential gain of wind-farm power with a cooperative control strategy between the wind turbines. Based on the Jensen wake model with the Katic wake superposition rule, the potential gain for the Nysted offshore wind farm is calculated...... to be 1.4–5.4% for standard choices 0.4 ≥ k ≥ 0.25 of the wake expansion parameter. Wake model fits based on short time intervals of length 15sec ≤ T ≤ 10 min within three months of data reveal a strong wake flow variability, resulting in rather broad distributions for the wake expansion parameter. When...

  5. Elsam. Offshore Wind Turbines. Horns Rev. Annual status report for the environmental monitoring programme 1. January 2004 - 31. December 2004

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-15

    In 2001, the former Ministry of the Environment and Energy granted Elsam A/S and Eltra A.m.b.A. approval to establish a wind farm capable of producing 160 MW of electric power, at Horns Rev, west of Blaevandshuk at the west coast of Jutland. According to the conditions of the approval, Elsam and Eltra were required to monitor the environmental effects of the wind farm by performing monitoring before, during and after construction of the wind farm. The environmental monitoring programme is financed through Public Service Obligation (PSO). Analogue to the Horns Rev wind farm another offshore demonstrational wind farm was established in the Baltic sea south of Lolland by Energi E2 the Nysted 165 MW offshore wind farm. To coordinate the environmental monitoring at the two demonstration wind farms at Nysted and Horns Rev within the framework of the approved budget, the Environmental Group of Danish Offshore Wind Farm Demonstration Projects was set up. The group consists of representatives from the Danish Forest and Nature Agency, the Danish Energy Authority, Elsam and Energi E2. The Environmental Group initiates, monitors and evaluates the environmental programmes continuously with respect to possible improvements and intensifications to ensure that the design of the individual programmes is optimal. After evaluation, the monitoring programmes are proposed by the Environmental Group and carried out after final approval by the Danish Energy Authority. The Environmental Group considers if there is reason to adjust the issues and priorities of the programmes based on previous experience or other inputs eg from the international expert panel, IAPEME (International Advisory Panel of Experts on Marine Ecology). IAPEME evaluates the environmental monitoring programmes and makes valuable suggestions and recommendations to the Environmental Group. The programmes have concentrated on the monitoring of possible impacts before, during and after construction to investigate and

  6. Apie lietuvių senųjų raštų atoninę įvardžio formą te ‘tave’

    Directory of Open Access Journals (Sweden)

    Auksė Razanovaitė

    2011-12-01

    Full Text Available ABOUT THE ATONIC FORM OF 2 SG. ACC. te IN THE OLD LITHUANIAN TEXTSSummaryIn the old Lithuanian texts the atonic form gen., dat., acc. m(i, t(i (Zinkevičius 1981, 49 is also used alongside the orthotonic genitive, dative and accusative forms of the first and the second person. The usual forms are mi, ti or the shortened ones -m or -t, except some forms te: used in the meaning of the second person accusative in the hymnal written by Saliamonas Mozerka Slavočinskis (SG IOzapay pamażu / Meldźiute pamażu SG I 60,4–5, Sunau te girdźiu raudanti / Aſż ſaweſp tawe biłanti SG I 95,16–17 and Aß teyſingay ir łáymingay / Gȧrbinċiau te tułomis SG II 98,26–27. It is interesting that the clitic -te is used instead of the usual -ti in the old writings. The above-mentioned forms cannot be analysed apart from the reflexive particle, the origin of which is pronominal as well. Hermann is known to have paid attention to this phenomenon (1926, 83. It is thought that the reflexive particle se reflects the Baltic *s (Zinkevičius 1966, 331f.; Mažiulis 1959, 13; Rosinas 1995, 36. With reference to the form the Balts can be thought to have had other forms of accusative of pronominal clitics, such as *m, *t (Rosinas 1995, 36. Consequently, the forms with -te attested in the hymnal of Slavočinskis and in „Knyga nobažnystės“ show that the Baltic *t enclitic form te ‘tave’ is directly attested.

  7. Wind energy applications of synthetic aperture radar

    Energy Technology Data Exchange (ETDEWEB)

    Bruun Christiansen, M.

    2006-11-15

    Synthetic aperture radars (SAR), mounted on satellites or aircraft, have proven useful for ocean wind mapping. Wind speeds at the height 10 m may be retrieved from measurements of radar backscatter using empirical model functions. The resulting wind fields are valuable in offshore wind energy planning as a supplement to on site measurements, which are costly and sparse, and model wind fields, which are not fully validated. Two applications of SAR measurements in offshore wind energy planning are addressed here: the study of wind farm wake effects and the potential of using SAR winds in offshore wind resource assessment. Firstly, wind wakes behind two large offshore wind farms in Denmark Horns Rev and Nysted are identified. A region of reduced wind speed is found downstream of both wind farms from the SAR wind fields. The wake extent and magnitude depends on the wind speed, the atmospheric stability, and the fraction of turbines operating. Wind farm wake effects are detected up to 20 km downwind of the last turbine. This distance is longer than predicted by state-of-the art wake models. Wake losses are typically 10-20% near the wind farms. Secondly, the potential of using SAR wind maps in offshore wind resource assessment is investigated. The resource assessment is made through Weibull fitting to frequency observations of wind speed and requires at least 100 satellite observations per year for a given site of interest. Predictions of the energy density are very sensitive to the wind speed and the highest possible accuracy on SAR wind retrievals is therefore sought. A 1.1 m s{sup -1} deviation on the mean wind speed is found through comparison with mast measurements at Horns Rev. The accuracy on mean wind speeds and energy densities found from satellite measurements varies with different empirical model functions. Additional uncertainties are introduced by the infrequent satellite sampling at fixed times of the day. The accuracy on satellite based wind resource

  8. Linearised CFD models for wakes

    Energy Technology Data Exchange (ETDEWEB)

    Ott, S.; Berg, J.; Nielsen, Morten

    2011-12-15

    This report describes the development of a fast and reasonably accurate model for the prediction of energy production in offshore wind farms taking wake effects into account. The model has been implemented as a windows application called Fuga which can run in batch mode or as a graphical user interface. Fuga is briefly described. The model is based on a linearization technique which is described in some detail, and linearized, governing equations are derived and written in a standard form based on a mixed-spectral formulation. A new solution method is used to solve the equations which involves intensive use of look-up tables for storage of intermediate results. Due to the linearity of the model, multiple wakes from many turbines can be constructed from the wake of a single, solitary turbine. These are in turn constructed from Fourier components by a fast Fourier integral transform of results derived from generic look-up tables. Three different models, based on three different closures, are examined: 1) the 'simple closure' using an unperturbed eddy viscosity kucentre dotz. 2) the mixing length closure. 3) the E-epsilon closure. Model results are evaluated against offshore wind farm production data from Horns Rev I and the Nysted wind farm, and a comparison with direct wake measurements in an onshore turbine (Nibe B) is also made. A very satisfactory agreement with data is found for the simple closure. The exception is the near wake, just behind the rotor, where all three linearized models fail. The mixing length closure underestimates wake effects in all cases. The E-epsilon closure overestimates wake losses in the offshore farms while it predicts a too shallow and too wide the wake in the onshore case. The simple closure performs distinctly better than the other two. Wind speed data from the the Horns rev met masts are used to further validate Fuga results with the 'simple' closure. Finally, Roedsand 1 and 2 are used as an example to illustrate

  9. Mesoscale wind fluctuations over Danish waters

    Energy Technology Data Exchange (ETDEWEB)

    Vincent, C.L.

    2010-12-15

    Mesoscale wind fluctuations affect the large scale integration of wind power because they undermine the day-ahead predictability of wind speed and power production, and because they can result in large fluctuations in power generation that must be balanced using reserve power. Large fluctuations in generated power are a particular problem for offshore wind farms because the typically high concentration of turbines within a limited geographical area means that fluctuations can be correlated across large numbers of turbines. Furthermore, organised mesoscale structures that often form over water, such as convective rolls and cellular convection, have length scales of tens of kilometers, and can cause large wind fluctuations on a time scale of around an hour. This thesis is an exploration of the predictability of mesoscale wind fluctuations using observations from the world's first two large offshore wind farms - Horns Rev I in the North Sea, and Nysted in the Baltic Sea. The thesis begins with a climatological analysis of wind fluctuations on time scales of 1-10 hours at the two sites. A novel method for calculating conditional climatologies of spectral information is proposed, based on binning and averaging the time axis of the Hilbert spectrum. Results reveal clear patterns between wind fluctuations and locally observed meteorological conditions. The analysis is expanded by classifying wind fluctuations on time scales of 1-3 hours according to synoptic patterns, satellite pictures and wind classes. Results indicate that cold air outbreaks and open cellular convection are a significant contributor to mesoscale wind variability at Horns Rev. The predictability of mesoscale wind fluctuations is tested by implementing standard statistical models that relate local wind variability to parameters based on a large scale weather analysis. The models show some skill, but only achieve a 15% improvement on a persistence forecast. The possibility of explicitly modelling

  10. Evaluation of efficiency of three molecular marker techniques for identifying poisonous plants%三种分子标记技术对有毒植物鉴定效能的评价

    Institute of Scientific and Technical Information of China (English)

    龙鑫; 孙承业; 谢立璟; 王英伟; 刘冰

    2013-01-01

    Objective To evaluate the efficiency of the three molecular marker techniques for identification of plant genus in order to select the most suitable molecular technique to rapidly identify a poisonous plant at the scene of the poisoning accident.Methods Nineteen samples of leaves in 18 species of common poisonous plants of Ranunculaceae and Euphorbiaceaec were selected.Genomic DNA of these samples were extracted using improved hexadecyltrimethylammonium bromide (CTAB) method,species identification (genus level) were performed using random amplified polymorphic DNA (RAPD),intersimple sequences repeats (ISSR) and DNA barcoding,cluster analysis were performed using NYSTS,SPSS,PAUP,and MEGA software.Accuracy,reliability,timeliness,and operability were compared between the 3 molecular marker techniques.Results Accuracy:genus level of samples failed to be identified using RAPD ; and the accuracy rates in genus level of identification using ISSR and DNA barcoding were 68% and 100%,respectively.Reliability:the subjective influence rates and the repetitive rates in RAPD and ISSR were 47% and 26% as well as 47% and 45%,respectively; the success rates of amplification and sequencing of trnH-psbA fragment using DNA barcoding both were 100%.Timeliness:the time from extraction of DNA to accomplishment of identification in the 3 molecular marker techniques were 8.5,9.0,and 42.2 h,respectively.Operability:species identification using RAPD and ISSR could be done in a common laboratory; special sequencing equipment was needed when using DNA barcoding technique in the identification of poisonous plants.Conclusion The preliminary study results show that DNA barcoding is a molecular identification technique more suitable for rapid determination of the poisonous plant at the scene of the sudden poisoning accident.%目的 评价3种不同的分子标记技术对植物属级的鉴定能力以选出最适合在中毒现场快速鉴定有毒植物的分子技术. 方法

  11. Environmental issues of offshore wind farms

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-07-01

    evaluation of data; 4. Procedures ElA (Environmental Impact Assessment) and other assessments. The meeting agreed to propose the COD project to handle these questions. After the meeting it was decided to develop a preliminary questionnaire (form) which can be used by the COD-project. No less than five presentations were given on the interaction between birds and wind energy. Tracking bird movement is a time consuming task. Methods incorporate surveying by aeroplane, radar, thermography and visual observations from platforms. The effect on the birds was summarised as: physical change of the habitat (i.e. resting areas); disturbance/avoidance effect (effects on foraging of sea birds); collision risk. In the ElA studies of Rodsand/Nysted and Horns Rev the behaviour of harbour porpoise and seal was also investigated. By tracking the migration movements of seal, their main routes could be studied. Grey seals travels larger distances, one went to Sweden while the Harbour seals stayed in the local area. In a project (MINOS) Harbour porpoise distribution in the North Sea and Baltic Sea (EEZ) will be studied. Detailed studies will be carried out locally like behaviour, habituation, curiosity and avoidance. A presentation was given on the expected changes of sediment structure by turbine foundations. The effects of wind farms can be: changes in the hydrodynamic system; changes of the sediment characteristics; changes of the benthos composition (increase of epibenthos); changes of the fish fauna with possible implication to fisheries. It was discussed, what relevance the changes in sedimentation will have in decision making processes. Changes leading to an increase of species (diversity), are judged differently. Due to the European Directive on EIA, which had to be transformed into national law of every European country, the building offshore requires an EIA study as a part of the licensing process. The levels of investigation and applied methods of assessments are apparently different