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 - 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 - RPRT A1 - Tillenburg, Dennis T1 - Technical challenges of floating offshore wind turbines - An overview N2 - Floating offshore wind (FOW) holds the key to 80 % of the total offshore wind resources, located in waters of 60 m and deeper in European seas, where traditional bottom-fixed offshore wind (BFOW) is not economically attractive. Many problems affecting floating offshore wind turbines (FOWT) were quickly overcome based on previous experience with floating oil rigs and bottom-fixed offshore wind. However, this technology is still young and there are still many challenges to overcome. This paper shows that electrical failures are amongst the most significant errors of FOWT. The most common cause was corrosion. It is also stated that the control system is most often affected, and that the Generator is frequently involved. Material corrosion is also the key factor when it comes to the most common overall reason for failures. A particular attention must be paid to mooring line fracture. Mooring lines are especially vulnerable to extreme sea conditions and the resulting fatigue, corrosion, impact damage, and further risks. It must be stated that the primary challenge is that of economics. Over time technological costs will decline making FOW more competitive and hence attractive for greater depth. T3 - EGU Master Journal of Renewable Energy Short Reviews - 2021_03 KW - floating offshore wind power KW - challenges KW - wind turbine KW - mooring line KW - Windkraftanlage Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-136770 ER - TY - RPRT A1 - Tchorz, Enno T1 - Sensorless maximum power point tracking systems in wind energy conversion systems - A review N2 - Wind energy conversion systems have attracted considerable attention as a renewable energy source due to depleting fossil fuel reserves and environmental concerns as a direct consequence of using fossil fuel and nuclear energy sources. The increasing number of wind turbines increases the interest in efficient systems. The power output of a wind energy conversion system depends on the accuracy of the maximum power tracking system, as wind speed changes constantly throughout the day. Maximum power point tracking systems that do not require mechanical sensors to measure the wind speed offer several advantages over systems using mechanical sensors. In this paper four different approaches that do not use mechanical sensors to measure the wind speed will be presented; the assets and drawbacks of these systems are highlighted, and afterwards the examined algorithms will be compared based on different characteristics. Finally, based on the analysis, an evaluation is made as to which of the presented algorithms is the most promising. T3 - EGU Master Journal of Renewable Energy Short Reviews - 2021_05 Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-136791 ER - TY - RPRT A1 - Steinigeweg, Joshua T1 - Review of the suitability of thermoplastic rotor blades in terms of the circular economy N2 - Wind energy has steadily gained importance in the generation of renewable energy over the last 25 years. A wind turbine has an average life expectancy of about 25 years. After that, thermoplastic composite materials from the rotors, among other things, accumulate and have to be recycled. Previous methods, such as landfilling, incineration and pyrolysis, have not yet proven to be effective in terms of the circular economy because the recycled material cannot be reused for equivalent products. The use of thermoplastic materials can be a sensible alternative, as thermoplastic resins can be recycled almost without loss of value due to their properties. Recycling of fibreglass is also possible with less loss of stiffness. In the future, it will be crucial to scale up thermoplastic rotor blades and create a market for the recycled material. T3 - EGU Master Journal of Renewable Energy Short Reviews - 2021_06 KW - Wind power KW - Recycling KW - Thermoplastic rotor KW - Solvolysis KW - Circular economy Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-136809 ER - TY - RPRT A1 - Speller, Julian T1 - Self-build small wind turbines - A review N2 - Self-build small wind turbines are used for rural electrification in the developed and developing world as well as for educational purposes. To give an overview about self-build small wind turbines a systematic literature review was conducted. The identified literature deals with two different vertical and horizontal axis turbine designs. The vertical axis turbines are both prototypes while one of the horizontal axis designs, the design by Piggott is widely used in rural electrification projects. Different papers dealing with the optimization of the Piggott design exist. In retrospect the conduction of a holistic review was not possible due to limited resources and length of this review. Nevertheless it can give a quick overview and a starting point for further research. T3 - EGU Master Journal of Renewable Energy Short Reviews - 2021_10 KW - small wind turbines KW - self-build KW - horizontal axis KW - vertical axis Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-136845 ER - TY - RPRT A1 - Schneid, Konrad A1 - Di Bernardo, Sascha A1 - Kuchen, Herbert A1 - Thöne, Sebastian T1 - Data-Flow Analysis of BPMN-Based Process-Driven Applications: Detecting Anomalies across Model and Code T2 - ERCIS Working Papers, 38 Y1 - 2021 UR - https://www.ercis.org/research/ercis-working-papers SN - 1614-7448 ER - TY - RPRT A1 - Schmeinck, Hendrik T1 - Impact of wind and wave induced platform motion on the aerodynamic properties of floating offshore wind turbines N2 - With floating offshore wind turbines, new sources of wind energy can be used, which cannot be tapped into by bottom-fixed wind turbine systems. However, due to their design, they experience additional motion caused by wind and wave loads. The motions that are induced into the system have an oscillating course. This affects the aerodynamic properties of the wind turbine and leads to changes in the thrust force and power output of floating wind turbines compared to bottom-fixed wind turbines. Furthermore, the motions lead to an earlier breakdown of the helical wake structure behind the wind turbine and moreover lead to a decreased reliability of the rotor blades. Differences in the effects of wind and wave loads on the aerodynamic performance of floating offshore wind turbines supported by different platform systems were found. T3 - EGU Master Journal of Renewable Energy Short Reviews - 2021_01 KW - floating offshore wind turbine KW - unsteady aerodynamics KW - six-degree-of-freedom motions KW - failure probabilities KW - rotor blade reliability Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-136750 ER - TY - RPRT A1 - Scheffler, Mark T1 - Low-Cost Hydropower Turbines for Developing Countries N2 - There are many hydropower turbines for low heads or low flows on a small scale. Many technologies are unsuitable for developing countries because equipment or materials are limited, high-tech machines are to expensive or spare parts are not readily available. This review combines currently available technologies with the requirements of developing countries in small, micro and pico hydropower. In small hydropower a propeller turbine from Thailand has a high efficiency of 70 to 80 percent at calculated production costs of around $ 513 per kW. Pumps as turbines are suitable for developing countries in micro hydropower due to readily availability, low price and an large number of standard sizes. In pico-scale, a low-cost Turgo wheel can be made of spoons for $ 48 and yields acceptable values in comparison to a 3D printed Pelton wheel for $ 822. While the Turgo wheel is suitable for high heads, a homemade siphon turbine can be used for low heads. The siphon turbine generates up to 200 W, is made of materials that are available anywhere in the world, and costs less than $ 50. T3 - EGU Master Journal of Renewable Energy Short Reviews - 2021_11 KW - hydropower KW - developing countries KW - low-cost KW - micro hydro KW - small hydro Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-136858 ER - TY - RPRT A1 - Olbertz, Niklas T1 - Sustainable hydro-power plants with focus on fish-friendly turbine design N2 - The impact of hydro-power plants on the ecosystem was studied with focus on the fish mortality and types of damage for many years. The fish mortality have a wide range of causes. Types of damage can be different and are caused by different parts of the power plant. The most dangerous part of the system are the fast moving turbine blades. They can cause blade strike and barotrauma due to the high speeds. Different types of turbines were developed for a better survival rate. Five different types of different research groups and manufacturers are presented in this paper. By considering those newly developed turbine designs, a fish survival rate from 96 % to 100 % is achieved. T3 - EGU Master Journal of Renewable Energy Short Reviews - 2021_13 KW - fish-friendly turbine KW - fish injury KW - sustainable hydro-power KW - Alden turbine KW - Minimum Gap Runner Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:836-opus-136876 ER -