TY - JOUR A1 - Zurhold, Roman T1 - Guidelines for Onshore Repowering in Germany JF - Educational Journal of Renewable Energy Short Reviews N2 - Wind energy plays a major role among renewable energies. Its expansion is therefore important in order to achieve the climate targets. Repowering is an important element in the expansion of wind energy. On the one hand, it offers a solution for many wind turbines in Germany that are no longer subsidised due to their age. On the other hand, modern turbines are significantly more powerful and enable more efficient land utilisation. This article provides an overview of the most important aspects of onshore repowering. There is a lot to consider when repowering wind turbines. The legal situation for repowering aims to be improved through simplified authorisation procedures. Even though efforts are being made by the government, there is still room for improvement. The repowering potential is also dependent on the various distance regulations to residential buildings in the federal states. These regulations might also be improved in the future. Another aspect is the remuneration, which is now closer to market developments due to the market premium model. It is also subject to greater competition as a result of the tendering process. At the same time, interest rates and turbine prices have risen, which creates economic challenges for the operators of future wind farms. Last but not least, repowering also depends on public acceptance. This is also to be regulated by law in the future. T3 - EGU Master Journal of Renewable Energy Short Reviews - 2024_14 KW - Onshore repowering KW - simplified authorisation procedure KW - distance regulations KW - market premium model KW - tendering Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-176520 SP - 85 EP - 93 ER - TY - JOUR A1 - Wos, Karolina A1 - Borghoff, Lisa Marie A1 - Horvat, Andrijana A1 - Paoletti, Flavio A1 - Saggia Civitelli, Eleonora A1 - Rembiałkowska, Ewa ED - Bacenetti, Jacopo T1 - Preliminary Analysis of Voluntary Information on Organic Milk Labels in Four European Union Countries JF - Sustainability N2 - The concern for the environment among European consumers is growing and in the future the need for sustainable shopping is expected to increase. Through transparent on-packaging communication with consumers, organic producers have the opportunity to show attributes of organic production system and build a strong market position. The aim of the study was to analyse voluntary packaging information on organic milk from four European markets in the context of organic food quality, i.e., Germany, the Netherlands, Italy and Poland. More specifically, the textual content of 106 organic milk packages was analysed and voluntary information on each package was categorized according to process- and product-related organic milk attributes. The assortment and content of voluntary packaging information varied across the four countries. The largest number of products was found on the German market (37) and the smallest on the Polish market (14). Dutch milk had the greatest amount of voluntary information on animal welfare, product locality, environmental protection, quality confirmation, naturalness and nutritional value. German milk had the most information on enjoyment and conditions of processing, while the Italian milk on the social perspective. The products available on the Polish market had the least voluntary information. Pasteurized organic milk had noticeably more information about organic quality attributes than micro filtrated and UHT milk. KW - milk package KW - organic KW - content analysis KW - optional KW - value Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-156981 SP - 1 EP - 18 PB - MDPI ER - TY - CHAP A1 - Wittrock, Ulrich A1 - Welp, Petra T1 - Adaptive laser resonator control with deformable MOEMS mirrors T2 - MEMS/MOEMS Components and Their Applications III, Proc. SPIE N2 - Adaptive laser resonators with deformable MOEMS mirrors under closed-loop control are discussed and experimental results are presented. The requirements for deformable mirrors and for closed-loop control systems of these mirrors are analyzed. Several deformable mirrors have been characterized and the results are presented. Currently available membrane mirrors deform under laser load and need further development before they can be used for aberration correction of solid state lasers above some tens of Watts. Nevertheless, the results are encouraging and the requirements are within reach of currently available technology. Finally, we demonstrate an Nd.YVO4-laser with a closed-loop adaptive resonator and more than 6 W of output power. The closed-loop system was able to compensate artificially introduced aberrations from a phase plate. Y1 - 2006 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-6537 VL - 6113 SP - 61130C PB - SPIE ER - TY - RPRT A1 - Wittor, Yannick T1 - Harvesting wind energy through electrostatic wind energy conversion - Comparison with common wind turbines and future possibilities N2 - Despite their important role in our energy system, common wind turbines have some disadvantages. Mainly, those disadvantages are connected to the intermediate conversion of wind energy in rotational energy. The resulting effects include maintenance costs and social acceptance problems. There are different technological approaches, that convert wind energy to electrical energy without its conversion to kinetic energy. As one of those technologies, the electrostatic wind energy conversion is to be discussed in this article. For this discussion, the historical development of this technology is presented. There are three important projects which will be presented to explain the technology and its different technological approaches. Those projects are the WPG, the EWICON and the SWET. Furthermore the results of those different experimental projects are collected and analyzed. On the basis of this analysis it is discussed, whether or not the electrostatic wind energy conversion could be of importance in a future energy system. Therefore the technology is set in relation to modern wind turbines. Also, important factors that influence the efficiency and energy output of those systems are outlined for further research. Due to different technological approaches a suggestion is made for the most promising system setting. T3 - EGU Master Journal of Renewable Energy Short Reviews - 2021_09 KW - electrostatic wind energy KW - wind energy KW - solid state wind energy KW - electrohydrodynamics KW - bladeless wind generator Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-136832 ER - TY - JOUR A1 - Winter, Corinna A1 - Brandes, Mirko A1 - Müller, Carsten A1 - Schubert, Tim A1 - Ringling, Michael A1 - Hillmann, Axel A1 - Rosenbaum, Dieter A1 - Schulte, Tim T. T1 - Walking ability during daily life in patients with osteoarthritis of the knee or the hip and lumbar spinal stenosis JF - BMC Musculoskeletal Disorders N2 - Background Degenerative musculoskeletal disorders are among the most frequent diseases occurring in adulthood, often impairing patients' functional mobility and physical activity. The aim of the present study was to investigate and compare the impact of three frequent degenerative musculoskeletal disorders -- knee osteoarthritis (knee OA), hip osteoarthritis (hip OA) and lumbar spinal stenosis (LSS) -- on patients' walking ability. Methods The study included 120 participants, with 30 in each patient group and 30 healthy control individuals. A uniaxial accelerometer, the StepWatch™ Activity Monitor (Orthocare Innovations, Seattle, Washington, USA), was used to determine the volume (number of gait cycles per day) and intensity (gait cycles per minute) of walking ability. Non-parametric testing was used for all statistical analyses. Results Both the volume and the intensity of walking ability were significantly lower among the patients in comparison with the healthy control individuals (p < 0.001). Patients with LSS spent 0.4 (IQR 2.8) min/day doing moderately intense walking (>50 gait cycles/min), which was significantly lower in comparison with patients with knee and hip OA at 2.5 (IQR 4.4) and 3.4 (IQR 16.1) min/day, respectively (p < 0.001). No correlations between demographic or anthropometric data and walking ability were found. No technical problems or measuring errors occurred with any of the measurements. Conclusions Patients with degenerative musculoskeletal disorders suffer limitations in their walking ability. Objective assessment of walking ability appeared to be an easy and feasible tool for measuring such limitations as it provides baseline data and objective information that are more precise than the patients' own subjective estimates. In everyday practice, objective activity assessment can provide feedback for clinicians regarding patients' performance during everyday life and the extent to which this confirms the results of clinical investigations. The method can also be used as a way of encouraging patients to develop a more active lifestyle. KW - Gait Cycle KW - Lumbar Spinal Stenosis KW - Walking Ability KW - Healthy Control Individual KW - Zygapophyseal Joint Y1 - 2010 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-168673 VL - 11 IS - 233 SP - 1 EP - 7 ER - TY - BOOK A1 - Wetter, Christof A1 - Brügging, Elmar T1 - 16. Steinfurter Bioenergiefachtagung - Tagungsband N2 - Dieser Tagungsband umfasste eine Übersicht zu den Vorträgen, Ausstellern sowie die Abstracts der Poster-Präsentation auf der 16. Bioenergiefachtagung. Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-177896 CY - Steinfurt ER - TY - JOUR A1 - Weißer, Hannes T1 - Relevance of Bird Strikes on Wind Turbines in Germany: A Review JF - Educational Journal of Renewable Energy Short Reviews N2 - As Germany aims to increase its utilization of wind power, the potential threat to bird populations due to this expansion is a controversial issue. This paper aims to collect data on the magnitude of bird strikes on wind turbines, review existing protective measures and explore innovative solutions. After a thorough examination of the literature, it was concluded that although the impact on bird populations is significant, it may be overemphasized in popular debates. This statement is not final as further research is necessary to assess the impact of bird strikes and explore new solutions. Comprehensive studies on this specific topic in Germany are limited, which makes a thorough evaluation challenging. While there are measures in place to protect species that may be negatively impacted, it is possible that these measures will not be adequate for all of them. While several innovative methods are under examination, progress in testing and implementation is slow. Lastly, an information problem was identified. Since the topic is highly politicized and polarizing, it is crucial to provide the public with accessible and reliable information on the discussed themes. This is currently not the case due to a lack of data and missing information campaigns. T3 - EGU Master Journal of Renewable Energy Short Reviews - 2024_13 KW - bird strike KW - wind power KW - red kite Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-176500 SP - 79 EP - 84 ER - TY - RPRT A1 - Wagenknecht, Fiona T1 - Assessment of noise mitigation measures during pile driving of larger offshore wind foundations N2 - Wind energy is an important source of electricity generation, but the construction of offshore wind foundations causes high underwater sound pressure, harming marine life. In this context limiting values for underwater noise emissions were set to protect the marine flora and fauna. Therefore, noise mitigation measures during pile driving are mandatory to comply with these limits. Current development in the wind industry lead to increasing wind turbine sizes, requiring a larger pile diameter, which leads to higher underwater noise emissions. As a result, the state of the art noise mitigation systems might not be sufficient and a combination of different technologies is necessary. This article focuses on the issue of noise mitigation during pile driving with respect to large pile sizes. First, the most tested and proven noise mitigation techniques (big bubble curtain, hydro sound damper, and IHC-noise mitigation system) are described, following an analysis of noise reduction measurements in applications at different offshore wind farm projects. In the end the suitability of current noise mitigation systems for large monopiles is evaluated, regarding their effectiveness and practicability. T3 - EGU Master Journal of Renewable Energy Short Reviews - 2021_04 KW - Noise mitigation measures KW - Offshore wind foundations KW - Big bubble curtain KW - Hydro sound damper KW - IHC-noise mitigation system Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-136786 ER - TY - JOUR A1 - Volkmer, Philipp T1 - Technical challenges and trends in upscaling wind turbines - A review JF - Educational Journal of Renewable Energy Short Reviews N2 - The upscaling of wind turbines has been increasing in recent years and will continue to play a significant role in the future, as it allows for the reduction of electricity generation costs. Various challenges arise when it comes to upscaling. This article summarizes the technical challenges associated with upscaling wind turbines and presenting their problem-solving approaches and research trends based on other reviews. It was found that the most frequently cited challenges are related to individual components, such as rotor blades, drive train, generator, tower, and noise impact. For rotor blades, the challenges are increased flexibility, more aeroelastic vibrations, increased wear, interferences with radar and transportation difficulties. Proposed solutions include the use of carbon-fiber blades, prebending, novel paints, and for transportation, segmented rotor blades and on-site manufacturing. In the gearbox, torque increases, leading to higher weight and susceptibility to errors. As a result, the trend is moving towards gearless systems with permanent magnet synchronous generators. Transportation is the major issue with towers, which can be resolved with on-site manufacturing. In terms of noise emission, reducing aerodynamic noise plays the most significant role. T3 - EGU Master Journal of Renewable Energy Short Reviews - 2024_12 KW - upscaling wind turbines KW - large wind turbines KW - trends and challenges wind turbines KW - wind turbine enlargement Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-176492 SP - 73 EP - 78 ER - TY - JOUR A1 - Tophoff, Lukas A1 - Kreyenschulte, Moritz A1 - Schüttrumpf, Holger A1 - Heimbecher, Frank T1 - Verockerung wasserbaulicher Filteranlagen: Stand der Wissenschaft und notwendige Untersuchungen JF - Grundwasser - Zeitschrift der Fachsektion Hydrogeologie N2 - In den letzten Jahrzehnten kam es in Einzelfällen zu schweren Schäden an wasserbaulichen geotextilen Filteranlagen infolge der Verstopfung durch ausgeflockte ockerhaltige Produkte. Durch eine starke Verminderung der Durchlässigkeit der Geokunststoffe in Kombination mit einem hohen hydrostatischen Druck wurden unter anderem die Deckschichten verschiedener Deckwerke in den tidebeeinflussten Wasserstraßen Ems und Weser angehoben und beschädigt. Bisher wurden die Milieubedingungen, d.h. Grundwasser- und Oberflächenwasserbeschaffenheit sowie Aquifer- und Deckwerksmaterial, unter denen die Ockerbildung in geotextilen und mineralischen Filteranlagen auftritt, noch nicht systematisch untersucht. Im Rahmen des vorliegenden Beitrags werden im ersten Schritt aus theoretischen Untersuchungen und Datenanalysen von Grundwasser- und Oberflächenwasseruntersuchungen Kriterien zur Bewertung der Verockerungsneigung abgeleitet. Diese Kriterien bzw. DOCP (decisive ochre clogging parameters) zeigen in den Ästuaren Ems, Weser und Elbe Beträge an, die Verockerungserscheinungen begünstigen bzw. ermöglichen. Auf Basis dieser Untersuchungen werden im zweiten Schritt Randbedingungen für zukünftige systematische in-situ Untersuchungen an wasserbaulichen Filteranlagen sowie im experimentellen Modell abgeleitet. KW - Deckwerksschäden KW - Grundwasseruntersuchungen KW - Verockerung KW - Wasserbau KW - Mineralische und geotextile Filter Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-152930 SP - 1 EP - 14 ER -