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The combined deployment of a PV and SW system in a residential building with an electric vehicle The interest in independent and sustainable energy supply is steadily increasing in times of continuously rising electricity prices and growing environmental awareness. While photovoltaic (PV) systems have almost become commonplace on roof surfaces and balcony railings, small wind (SW) turbines are still relatively rare. This is despite the fact that wind power accounts for over 50 % of the renewable energy generated in Germany and is subject to significantly lower fluctuations throughout the year compared to solar radiation. The aim of the calculations presented in this article therefore was to exemplarily examine whether the combined use of photovoltaic and small wind turbine systems on residential buildings represents both an energetically and an economically viable course of action. It was also necessary to analyse the importance of using and charging an electric vehicle in the context of the system combination. The resulting economic efficiency of the combined systems was determined by comparing software‐based yield forecasts for a specific location with the load profile of an average 3‐person household. [ABSTRACT FROM AUTHOR]

Copyright of Tribologie und Schmierungstechnik is the property of Narr Francke Attempto Verlag GmbH & Co.KG and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Onshore wind energy development is often delayed or even prevented by local resistance. Against this backdrop, we discuss financial participation as a measure to promote local acceptance by positively influencing the perceived experience of justice. Building on the concept of energy justice, this paper investigates the extent to which different forms of financial participation are suitable for better distributing costs and benefits, creating opportunities for participation, and examining who can participate financially. In addition to a comprehensive literature review, interviewswere conducted with wind turbine planners and operators. These show that stakeholders engage in financial participation to different degrees across different projects and that the preferred form of participation varies from one region to another. Moreover, no model of financial participation appears to be suited to address all dimensions of energy justice, as all models are characterised by certain advantages and disadvantages. Therefore, the availability of financial participation options alone is unlikely to increase local acceptance. Such options can, however, be effective when combined with other measures to increase acceptance. [ABSTRACT FROM AUTHOR]

Effects of imperfections on joint bearing capacity of segmented tower structures Hybrid tower structures for wind turbines have become established in recent years, especially for turbines with large hub heights. The upper part of these towers consists of steel sections, whereas the lower part is made up of prestressed precast concrete rings. The horizontal joints between the precast concrete elements are usually designed as dry joints. Due to the lack of a compensation layer in the joint, increased demands are made on the accuracy of the joint surfaces. From measurement data of real segments of wind turbines, it could be deduced that the joint surfaces show imperfections with respect to the cross‐sectional shape and flatness. Numerical simulations were used to investigate the influence of these imperfections on the joint support behaviour under combined loading of prestressing, bending and torsion. It is shown that, depending on the type of imperfection and the degree of prestressing, imperfections can have a considerable influence on the joint load‐bearing behaviour. [ABSTRACT FROM AUTHOR]

Copyright of Technikgeschichte is the property of Nomos Verlagsgesellschaft mbH & Co. KG and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Integrated design and operation methodology for offshore megastructures The collaborative research centre 1463 "Integrated Design and Operation Methodology for Offshore Megastructures" was established by the German Research Foundation in January 2021 for an initial period of four years. In 15 sub‐projects, researches from five institutions under the leadership of Leibniz University Hannover are investigating and developing new methods to realize future offshore wind turbines with a rated power of > 20 MW as a significant contribution to a renewable energy supply. [ABSTRACT FROM AUTHOR]

Advanced torsional bearing model of external prestressed circular ring segments with dry joints The frequent application of dry joints as connection technology in the field of wind turbine towers and prefabricated bridge construction demands improvement of the calculation model of these connections. This article describes the development of an interaction model for the determination of torsional load‐bearing capacity under shear forces and bending loads applied on circular ring segments. The model considers both the interaction with all loading conditions and the alternating effect of gaping joints due to the bending load. Previous models describe the load‐bearing capacity of circular ring segment joints insufficiently or without considering interactions with shear forces or the bending moment. Finally, the results of the developed model are compared to numerical calculations showing satisfactory agreement. [ABSTRACT FROM AUTHOR]

Digitalization and the use of sensor data for the condition monitoring of surface protection systems of steel towers of onshore wind power structures The paper describes the concept of a fully data‐based, mainly automated, procedure for the condition monitoring of surface protection systems on steel structures. Acquisition, processing and evaluation of relevant data as well as their implementation into a mathematical‐empirical condition monitoring model are discussed. The monitoring model is based on the definition and assessment of a local deterioration degree, which is characteristic for pre‐defined reference areas at the structure. The creation of the reference areas by means of In‐situ Virtual Twin Computation is introduced. The data‐based assessment procedure is practically exemplified on a steel tower of an onshore wind power structure in a rural corrosive environment. The procedure can be applied to steel structures with similar geometries (storage tanks, silos, chimneys) as well as to offshore conditions. [ABSTRACT FROM AUTHOR]

Wenn man räumliche Planung verstehen möchte, ist es wichtig, die Selbstverständnisse und beruflichen Identitäten der handelnden Akteure zu kennen. Bislang ist dazu in Deutschland kaum geforscht worden. Der Beitrag basiert auf einem Forschungsansatz, der berufliche Identitäten als Ergebnis des Zusammenwirkens gesellschaftlicher Anforderungen und eigener Handlungen in den Fokus rückt. Es wird gezeigt, welche Rollen Regionalplanern von außen zugewiesen werden und wie Regionalplaner selber ihre beruflichen Identitäten wahrnehmen und daran arbeiten. Anhand von Dokumentenanalysen und autobiographisch-narrativen Interviews wird untersucht, welche Subjektpositionen in schriftlichen Diskursfragmenten, die sich auf Regionalplanung und Windenergie beziehen, zu finden sind, welchen äußeren Anforderungen sich Regionalplaner ausgesetzt sehen, welche Ansprüche sie selber an ihr berufliches Handeln stellen, welche Techniken des Selbst sie praktizieren und welche diesbezüglichen Spannungen sie wahrnehmen. Die Ergebnisse knüpfen an internationale Untersuchungen über planerische Identitäten an und können als Angebot an die Praxis gelesen werden, individuelle Praktiken und Spielräume der Identitätsarbeit zu reflektieren.

Model development for torsion stressed circular ring segments with dry joints The segment construction method for wind turbine towers has established itself in the production of large hub heights in the form of hybrid constructions. Hybrid towers consist of steel pipes in the upper part and usually pre‐stressed reinforced concrete segments in the lower part. The horizontal joints in the reinforced concrete structure are generally constructed as a grinded dry joint without shear serrations. Therefore, shear forces in the joints can only be transmitted by friction, especially for the calculation of the ultimate limit state (ULS), in which case torsion is relevant and the joints open due to a bending load. The current theories are based on the known torsion theories according to Saint‐Venant, which are not fully applicable to this construction method. Based on the theoretical considerations from [1], a torsion support model for circular ring segments with dry joints is developed in this paper. Subsequently, this model is compared with numerical simulations and experimental results. [ABSTRACT FROM AUTHOR]

Numerical modelling of the force‐deformation behaviour of preloaded bolts in L‐flange joints Steel tube towers for wind energy turbines are support structures prone to vibrations, which are subjected to oscillating loads due to the turbine operation. Therefore the fatigue assessment of the tower is of high importance. A critical point within the tower structure is the ring flange connection, which connects single tower sections to each other with preloaded bolts. Regarding the fatigue strength of this connection the assurance of a sufficiently high bolt preload is essential. A precise gathering of the connection behavoir in the plastic region is important for a realistic prediction of the remaining preload level in a flange connection after an overload. In the present article a numeric approach for the prediction of preload losses due to high single loads is presented for centrically and eccentrically preloaded bolted connections. The presented approach is verified by tests. [ABSTRACT FROM AUTHOR]

Soil vibrations induced by wind turbines The towers of wind turbines (WT) are constantly excited due to the rotation of the rotor, hub, gear and generator. The resulting vibrations, generated at the upper end of the tower, are modified by the dynamic properties of the tower structure and induced into the ground. Broadband seismometers record these vibrations not only in the close environment of the WT but also up to several kilometers away from the turbine. In addition, residents and wind power opponents fear a potential of negative health effects caused by these vibration phenomena. In the context of this paper, seismic vibrations are measured at the foundation of an exemplary 2 MW WT. These seismic signals are compared to numerical simulations. Based on this, the technical background of the source mechanism is explained. So far, the measured ground vibrations usually have been attributed exclusively to the excitation frequencies of the WT. However, the investigations presented in this article show that the structural properties of the tower structure influence the type and intensity of the vibrations introduced into the ground and dominate the emitted ground motion amplitudes. Finally, it is shown that the use of absorbers can cause a significant reduction of the vibrations. [ABSTRACT FROM AUTHOR]

Design at the limit – opportunities of large scale physical testing for an efficient design Support structures for wind energy converters have become serial products. More than 1 350 wind turbines are installed offshore only in the German North and Baltic Sea. Structures of large dimensions being highly dynamically loaded and located in a harsh offshore environment are challenging and moving at the limit of design standards. However, serious damages are rare. This is obviously positive, but meaning on the other side that there might be potential for dimensioning structures more efficiently. Driven by high cost pressure these reserves have to be quantified and potentials have to be demonstrated. Large scale experiments in particular offer possibilities for a more individual design of structures. With the objective of validating and optimising design approaches the Test Center for Support Structures in Hannover was founded in 2014. Here, large scale components and structures can be analysed and tested. This paper summarises the findings of research projects in the recent past. The regarded projects deal with the development of new tower concepts in steel for large hub heights, with the fatigue of thick‐walled welded structures considering special aspects of corrosion, and with the development of a structural health monitoring system in order to ensure the reliability of grouted connections. [ABSTRACT FROM AUTHOR]

Zusammenfassung Die Energiewende hat zum Ziel, den Energiebedarf Deutschlands komplett aus erneuerbaren Energiequellen zu decken. Ist das innerhalb des Landes möglich? Im Prinzip ja, zeigen Abschätzungen. Der Schlüssel ist die direkte Nutzung der Solarenergie, denn sie liefert mehr als genug erneuerbare Energie. Erneuerbare Energiequellen wie Wind, Wasserkraft oder Biomasse entstehen aus der Solarstrahlung über Umwandlungsketten mit oft geringen Wirkungsgraden. Ihre Potenziale sind entsprechend niedriger, besonders ineffizient ist die Biomasse. Auch der große Beitrag des Winds in derzeitigen Zukunftsszenarien der Energiewende ist kritisch zu bewerten. Die Nutzungsgrenzen der Windenergie werden wahrscheinlich bereits innerhalb dieser Szenarien überschritten. Da Solarenergie aber jahreszeitlich stark schwankt, sind effiziente Energiespeicher oder der Schritt über die Grenzen Deutschlands hinaus notwendig. Dann gelingt die Wende zu 100 % erneuerbarer Energie. [ABSTRACT FROM AUTHOR]

Zusammenfassung Eine Frage, die beim Ausbau erneuerbarer Energieerzeugung immer wieder aufkommt, ist die nach dem Flächenbedarf. Eine Abschätzung auf Basis heutiger Daten zeigt: Grundsätzlich ist mehr als genug Platz in Deutschland für eine hundertprozentige Umstellung der Stromproduktion auf Sonne, Wasser und Wind. Global gesehen gilt dies sogar für eine auf zehn Milliarden angewachsene Menschheit. Dabei muss allerdings die Solarenergie einen wesentlichen Anteil übernehmen. [ABSTRACT FROM AUTHOR]

Copyright of Industrielle Beziehungen is the property of Rainer Hampp Verlag and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Torsional behavior of a segment tower with an alternative joint design Based on the most commonly constructed segment wind turbine towers at present, a further developed design of joints is described in this article. The dry joint which works without balancing layer of epoxy or cement mortar has been applied to wind turbine towers in the horizontal direction for many years. It should also be applied in the vertical direction. The evenness in the joint will be assured with the help of a high‐precision milling machine. Therefore, the compactness and force transmission of the construction can be guaranteed. However, a decrease of structural resistance is still observed through numerical simulation. By changing the integral cross section to an open half‐ring segment, the weak part can be easily pointed out in the structure design itself and also by current design approaches. There are currently no suitable theories or regulations for this kind of structural design. [ABSTRACT FROM AUTHOR]

Die aerodynamische Leistungsfähigkeit von Windenergierotorblättern wird durch Erosion und Kontamination der Rotorblattvorderkante negativ beeinflusst. Konventionelle Verfahren zur Messung der Strömungsgrenzschicht an Windenergierotorblättern sind invasiv und beeinflussen die zu messende Strömung. Daher wird ein nicht-invasives, auf der thermografischen Strömungsvisualisierung basierendes Verfahren vorgestellt, mit dem sich der Grad der Strömungsbeeinflussung aufgrund von Erosion und Kontamination erstmals an realen Windenergieanlagen in Betrieb quantifizieren lässt. Dies erfolgt über die Lokalisierung des laminar-turbulenten Strömungsumschlags und einer geometrischen Zuordnung der zweidimensionalen Kameramessdaten zur dreidimensionalen Rotorblattgeometrie. Eine exemplarische Messung an einer 1,5MW Windenergieanlage offenbart einen Kontaminationsgrad von bis zu 5,2% bei einer Messunsicherheit von 0,1 %. The aerodynamic performance of wind energy rotor blades is negatively affected by erosion and contamination of the rotor blade leading edge. Conventionally used methods for boundary layer flow measurements at wind turbines are invasive and affect the flow itself. Therefore, a non-invasive method based on thermographic flow visualization is presented, which enables the quantification of the degree of influenced boudary layer flow due to erosion and contamination for the first time. The method can be used at real-scale wind turbines in operation. The localization of the laminar-turbulent transition and a geometric assignment of the two-dimensional camera measurement data to the three-dimensional rotor blade geometry are the basis for this purpose. An example measurement at a 1.5MW wind turbine reveals a contamination level of up to 5.2% with a measurement uncertainty of 0.1 %. [ABSTRACT FROM AUTHOR]

Copyright of Zeitschrift für Wirtschaftsgeographie is the property of De Gruyter and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Torsion structural behavior of external prestressed circular segments with dry joints In the tower construction of wind power plants concrete or hybrid towers are established, especially for high towers, they have replaced the traditional steel towers due to better transportability. The needed joints for the prefabricated construction method leads to problems, which are not satisfactorily resolved by the current models and calculation approaches. In the case of the formation of dry joints (horizontal joints) between the segments, the force transmission of the lateral forces and torsion moments take place exclusively through the friction in the joint, the external prestressing and the coefficient of friction generate the frictional resistance. The capacity of lateral force between the joints should be calculate by a linear calculation approach, that the permissible transverse force corresponds to the prestressing force multiplied by the coefficient of friction. For the transmission of the torsional moments, the calculation is carried out according to the known torsion theories of Bredt and Saint-Venant, as long as the joints are overpressed, they can transmit a very high torsional moment. However, in the ultimate limit state, if the joint begin to open, the permissible torsional moment drops immediately to a very small value and thus becoming a critical criterion for the tower. According to recent investigations, these approaches witch describe the bearing and deformation behavior of such a joints are incorrect, results in an uncertainty range and a very large unused potential. [ABSTRACT FROM AUTHOR]

Damping of wind turbines The hub heights of wind turbines in Germany have significantly increased over the years. The requirements for these towers are also increasing - especially due to the high focus on costs. Since turbines are increasingly installed with variable rotor speeds, there is a high incentive to avoid potential resonance issues. This article investigates the influence of the structural damping on the mechanical loads on high hybrid-towers. A new method to estimate the structural damping is proposed, which has been validated by means of a full-scale measurement campaign. [ABSTRACT FROM AUTHOR]

Development of soft towers for wind energy plants - Softtower. The tower plays an increasingly important role in the wind energy due to the fact that tower and foundation are responsible for the overall costs up to 45 %. For further yield increase the tower height will go up to 160 m in the future. Soft towers, designed purposefully with their natural frequency in the area of resonance of the rotor, will be developed to work against the growing cost pressures. This gives the tower a key role in the development of turbine control and load simulation. This article describes how the soft tower along with the turbine as a unit will determine the future wind energy plants. The aero-elastical relations and the related positive aero-dynamical damping will be implicated and analysed. [ABSTRACT FROM AUTHOR]

This study aims to analyse the perception of cultural landscape by local communities, with emphasis on representatives of Generation Y in the sense of people aged between 16 and 34 in the context of the development of wind energy identified through the location of wind-power plants. We have chosen to study the commune of Dąbrowa Chełmińska (LAU-2, Kuyavian-Pomeranian Voivodeship [województwo kujawsko-pomorskie], NUTS-2), a suburban area housing one of the oldest wind-power plants in Poland as well as modern installations. We achieved the aim of this paper by conducting a bipartite study using questionnaire interviews and Wejchert's impression-curve method. The analyses we have performed indicate that matters related to cultural landscape engage every resident of the commune, yet primarily the younger generation: Generation Y. This is a social group interested in processes, which are currently underway, especially those regarding innovation and ecological actions. The study shows that the perception of cultural landscape comprising wind-power plants by the local community, including Generation Y, is primarily ambivalent. We are dealing with diverse, sometimes even contrasting opinions, both among young people and the generation of their parents and grandparents. Generation Y gives a more negative assessment of the presence of wind turbines in cultural landscape than the generation of parents and grandparents. It may seem surprising that in the view of the respondents, wind-power plants do not dominate the landscape, although representatives of Generation Y stated that they should be removed as elements disharmonising the landscape. [ABSTRACT FROM AUTHOR]

Site-specific assessment of wind turbines: A pragmatic approach In Germany formal building regulations often request site-specific assessments of all Wind Turbine Generators (WTG) including new and existing ones. When using the current technical methods and guidelines, the assessment cannot be completed for all WTG, if the wind farm consists of different WTG types (produced by different manufacturers). Thus, in order to comply with the regulations, operators of WTG are forced to curtail the power of many WTG. In the present document a technical method is described extending the existing methodo logy for site-specific assessments according to DIBt 2012. The technical method describes a simplified load estimation model, which would enable other expert engineers - not only the manufacturer of the WTG - to carry out capacity checks as well. [ABSTRACT FROM AUTHOR]

Bu çalışmada, enerji ihtiyacının karşılanmasında gelecekte daha fazla rol alacağı anlaşılan rüzgar enerjisinin, dünya ve Türkiye'deki kullanımına ilişkin genel bir durum değerlendirmesi yapılmıştır. Bu amaçla; öncelikle dünya ve Türkiye'de rüzgar enerjisi kullanımının tarihsel gelişimi aktarılmış, ardından da rüzgar enerjisi potansiyeli, rüzgarın oluşumu ve rüzgar ölçümleri üzerinde durulmuştur. Daha sonra da; rüzgarın güvensizliği, bir evin elektrik enerjisi gereksiniminin sadece rüzgardan karşılanması ve rüzgar elektriğinin ekonomikliği konularındaki rüzgar enerjisi kullanımına yöneltilen eleştiriler irdelenerek, somut cevaplar verilmiştir.

Die etablierten konventionellen Windturbinen rotieren um eine horizontale Drehachse. Deshalb benötigen sie eine aufwendige Nachführung in die Windrichtung und meist ein Getriebe zwischen Rotor und Generator. Windenergieanlagen mit vertikaler Achse, sogenannte H-Rotoren, sind dagegen deutlich einfacher aufgebaut. Sie sind robust, wartungsarm und laufen fast geräuschlos. Daher eignen sie sich für den Betrieb an entlegenen Orten in sogenannten Insellösungen, in lokalen Netzen, aber auch in Städten. Ihr Wirkungsgrad ist nicht prinzipiell geringer als bei herkömmlichen Anlagen. Fortschritte in Konstruktion und Steuerung lassen auf einen baldigen kommerziellen Durchbruch im Bereich der kleinen und mittleren Anlagen hoffen. [ABSTRACT FROM AUTHOR]

Conflicts about natural resources in countries of the global South have consistently gained more political and scholarly attention. In the context of climate protection and the 'green economy discourse', contentious renewable energy projects are becoming an important area of research. In the Mexican state of Oaxaca in the region of Istmo de Tehuantepec, local asambleas (assemblies) criticize the implementation of wind parks by transnational corporations, arguing that the latter as well as the Mexican state are ignoring and violating agrarian and indigenous rights guaranteed in the International Labour Organization (ILO) convention 169. This article gives a brief overview of the conflict in Istmo and argues that the implementation of wind parks is reproducing and intensifying existing structural conflicts surrounding land rights and competing processes of participation. [ABSTRACT FROM AUTHOR]

In this paper, an attempt is made to estimate the available wind energy along the coasts and over the islands of Greece, based on data from 34 anemometer stations. A seasonal and annual climatological estimate of wind speed and wind power density at 10 m was made first. Similarly, the mean maximum available wind energy was also estimated at 10 and 50 m. The vertical extrapolation of wind energy was based on the power law expression. On the western coasts and islands, the annual natural wind energies at 50 m above ground lie between 500 and 1500 kWh-m-2 and on the eastern coasts and islands between 500 and 8000 kWh-m-2. For the mountainous areas of Greece, good sites for wind machines might exist in the elevated eastern and western exposed parts of Greece.

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Copyright of e & i Elektrotechnik und Informationstechnik is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of e & i Elektrotechnik und Informationstechnik is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of e & i Elektrotechnik und Informationstechnik is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of e & i Elektrotechnik und Informationstechnik is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of e & i Elektrotechnik und Informationstechnik is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In den letzten beiden Jahrzehnten ist der Markt für Windenergieanlagen rasant gewachsen und hat dadurch auch eine dynamische Weiterentwicklung der entsprechenden Technologien ermöglicht. Initiiert durch die Novellierung des Erneuerbare Energien-Gesetzes sowie durch das Ablaufen der genehmigten Nutzungsdauer bei den Anlagen der Ersten Generation, gewinnt der Ersatz alter Windenergieanlagen zunehmend an Bedeutung. Wachsende Rotordurchmesser und Turmhöhen stellen zudem neue Anforderungen an Tragwerksplaner, Prüfer und Überwacher. Im Beitrag werden Empfehlungen des Bau-Überwachungsvereins BÜV für die Bauüberwachung und wiederkehrende Prüfung von Windenergieanlagen an Land vorgestellt. BÜV recommendations for supervision of onshore wind energy plants In the last two decades, the sector of wind energy plants has grown rapidly and therefore enabled also a dynamic development of relevant technologies. Initiated by revision of the Renewable Energy Law as well as by the expiration of the approved life of first generation plants, the replacement of ancient wind energy plants has gained increasing significance. Increasing rotor diameters and tower heights lead additionally to new demands on structural engineers, checking engineers and supervisors. In the attached text recommendations of the Bau-Überwachungsverein BÜV regarding site supervision and periodic inspections of onshore wind energy plants are presented. [ABSTRACT FROM AUTHOR]