@article{KlemmWiese2022, author = {Klemm, Christian and Wiese, Frauke}, title = {Indicators for the optimization of sustainable urban energy systems based on energy system modeling}, series = {Energy, Sustainability and Society}, volume = {12}, journal = {Energy, Sustainability and Society}, number = {3}, publisher = {Springer Nature}, doi = {10.25974/fhms-14513}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:836-opus-145136}, pages = {1 -- 20}, year = {2022}, abstract = {Background: Urban energy systems are responsible for 75 \% of the world's energy consumption and for 70 \% of the worldwide greenhouse gas emissions. Energy system models are used to optimize, benchmark and compare such energy systems with the help of energy sustainability indicators. We discuss several indicators for their basic suitability and their response to changing boundary conditions, system structures and reference values. The most suitable parameters are applied to four different supply scenarios of a real-world urban energy system. Results: There is a number of energy sustainability indicators, but not all of them are suitable for the use in urban energy system optimization models. Shortcomings originate from the omission of upstream energy supply chains (secondary energy efficiency), from limited capabilities to compare small energy systems (energy productivity), from excessive accounting expense (regeneration rate), from unsuitable accounting methods (primary energy efficiency), from a questionable impact of some indicators on the overall system sustainability (self-sufficiency), from the lack of detailed information content (share of renewables), and more. On the other hand, indicators of absolute greenhouse gas emissions, energy costs, and final energy demand are well suitable for the use in optimization models. However, each of these indicators only represents partial aspects of energy sustainability; the use of only one indicator in the optimization process increases the risk that other important aspects will deteriorate significantly, eventually leading to suboptimal or even unrealistic scenarios in practice. Therefore, multi-criteria approaches should be used to enable a more holistic optimization and planning of sustainable urban energy systems. Conclusion: We recommend multi-criteria optimization approaches using the indicators of absolute greenhouse gas emissions, absolute energy costs, and absolute energy demand. For benchmarking and comparison purposes, specific indicators should be used and therefore related to the final energy demand, respectively the number of inhabitants. Our example scenarios demonstrate modeling strategies to optimize sustainability of urban energy systems.}, language = {en} } @article{HoernschemeyerSoefkerRienietsNiestenetal.2022, author = {H{\"o}rnschemeyer, Birgitta and S{\"o}fker-Rieniets, Anne and Niesten, Jan and Arendt, Rosalie and Kleckers, Jonas and Klemm, Christian and Stretz, Celestin Julian and Reicher, Christa and Grimsehl-Schmitz, Winona and Wirbals, Daniel and Bach, Vanessa and Finkbeiner, Matthias and Haberkamp, Jens and Budde, Janik and Vennemann, Peter and Walter, Gotthard and Flamme, Sabine and Uhl, Mathias}, title = {The ResourcePlan — An Instrument for Resource-Efficient Development of Urban Neighborhoods}, series = {Sustainability}, volume = {14}, journal = {Sustainability}, number = {3}, publisher = {MDPI}, doi = {10.25974/fhms-14854}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:836-opus-148545}, year = {2022}, abstract = {In Germany, the current sectoral urban planning often leads to inefficient use of resources, partly because municipalities lack integrated planning instruments and argumentation strength toward politics, investors, or citizens. The paper develops the ResourcePlan as (i) legal and (ii) a planning instrument to support the efficient use of resources in urban neighborhoods. The integrative, multi-methodological approach addresses the use of natural resources in the building and infrastructural sectors of (i) water (storm- and wastewater) management, (ii) construction and maintenance of buildings and infrastructure, (iii) urban energy system planning, and (iv) land-use planning. First, the development as legal instrument is carried out, providing (i) premises for integrating resource protection at all legal levels and (ii) options for implementing the ResourcePlan within German municipal structures. Second, the evaluation framework for resource efficiency of the urban neighborhoods is set up for usage as a planning instrument. The framework provides a two-stage process that runs through the phases of setting up and implementing the ResourcePlan. (Eco)system services are evaluated as well as life cycle assessment and economic aspects. As a legal instrument, the ResourcePlan integrates resource protection into municipal planning and decision-making processes. The multi-methodological evaluation framework helps to assess inter-disciplinary resource efficiency, supports the spatial identification of synergies and conflicting goals, and contributes to transparent, resource-optimized planning decisions.}, language = {de} } @article{KlemmWieseVennemann2023, author = {Klemm, Christian and Wiese, Frauke and Vennemann, Peter}, title = {Model-based run-time and memory reduction for a mixed-use multi-energy system model with high spatial resolution}, series = {Applied Energy}, volume = {334}, journal = {Applied Energy}, issn = {0306-2619}, doi = {10.1016/j.apenergy.2022.120574}, pages = {120574}, year = {2023}, abstract = {Local and regional energy systems are becoming increasingly entangled. Therefore, models for optimizing these energy systems are becoming more and more complex and the required computing resources (run-time and random access memory usage) are increasing rapidly. The computational requirements can basically be reduced solver-based (mathematical optimization of the solving process) or model-based (simplification of the real-world problem in the model). This paper deals with identifying how the required computational requirements for solving optimization models of multi-energy systems with high spatial resolution change with increasing model complexity and which model-based approaches enable to reduce the requirements with the lowest possible model deviations. A total of 12 temporal model reductions (reduction of the number of modeled time steps), nine techno-spatial model reductions (reduction of possible solutions), and five combined reduction schemes were theoretically analyzed and practically applied to a test case. The improvement in reducing the usage of computational resources and the impact on the quality of the results were quantified by comparing the results with a non-simplified reference case. The results show, that the run-time to solve a model increases quadratically and memory usage increases linearly with increasing model complexity. The application of various model adaption methods have enabled a reduction of the run-time by over 99\% and the memory usage by up to 88\%. At the same time, however, some of the methods led to significant deviations of the model results. Other methods require a profound prior knowledge and understanding of the investigated energy systems to be applied. In order to reduce the run-time and memory requirements for investment optimization, while maintaining good quality results, we recommend the application of (1) a pre-model that is used to (1a) perform technological pre-selection and (1b) define reasonable technological boundaries, (2) spatial sub-modeling along network nodes, and 3) temporal simplification by only modeling every nth day (temporal slicing), where at least 20\% of the original time steps are modeled. Further simplifications such as spatial clustering or larger temporal simplification can further reduce the computational effort, but also result in significant model deviations.}, language = {en} } @article{KlemmBeckerTocklothetal.2023, author = {Klemm, Christian and Becker, Gregor and Tockloth, Jan N. and Budde, Janik and Vennemann, Peter}, title = {The Spreadsheet Energy System Model Generator (SESMG): A tool for the optimization of urban energy systems}, series = {Journal of Open Source Software}, volume = {8}, journal = {Journal of Open Source Software}, number = {89}, issn = {2475-9066}, doi = {10.25974/fhms-17084}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:836-opus-170845}, pages = {5519}, year = {2023}, abstract = {The Spreadsheet Energy System Model Generator (SESMG) is a tool for modeling and optimizing energy systems with a focus on urban systems. The SESMG is easily accessible as it comes with a browser-based graphical user interface, spreadsheets to provide data entry, and detailed documentation on how to use it. Programming skills are not required for the installation or application of the tool. The SESMG includes advanced modeling features such as the application of the multi-energy system (MES) approach, multi-objective optimization, model-based methods for reducing computational requirements, and automated conceptualization and result processing of urban energy systems with high spatial resolution. Due to its accessibility and the applied modeling methods, urban energy systems can be modeled and optimized with comparatively low effort.}, language = {en} } @article{Goray2023, author = {Goray, Lars}, title = {Life cycle energy analysis and ecological impact of wind turbines - a comparison of life cycle assessments}, series = {Educational Journal of Renewable Energy Short Reviews}, journal = {Educational Journal of Renewable Energy Short Reviews}, doi = {10.25974/ren_rev_2023_02}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:836-opus-172613}, pages = {8 -- 15}, year = {2023}, abstract = {The use of wind power is rapidly expanding worldwide. It is important to examine the impact of wind turbines on the environment to see if they provide a net benefit and to identify potential for improving. Therefore life cycle assessments (LCA) of different wind turbine types are compared in this short review. The results are then shown side by side in tables for comparison. Overall the LCAs show that wind turbines compensate the required energy and emitted pollutants after approx. 6-16 months. The energy payback period (EPP) for 2 MW onshore wind turbines remained roughly the same since 2009 with approximately 7 months. Onshore wind turbines have a higher impact due to emissions but a shorter EPP than offshore wind turbines. The estimated service life of 20 years should be maximized to ensure a high energy yield ratio. The biggest impact on the environment results from the processes to provide the building material e.g. steel and cement. That impact could be reduced by 20 \% if recycled steel would be used. It is shown that wind power is one of the cleanest energy sources. But further investigations in material processing and recycling are important to improve the eco-balance of wind turbines.}, language = {en} } @article{Plascher2023, author = {Plascher, Gregor}, title = {Current systems and potential areas for tidal power plants - A review - Using the example of the United Kingdom}, series = {Educational Journal of Renewable Energy Short Reviews}, journal = {Educational Journal of Renewable Energy Short Reviews}, doi = {10.25974/ren_rev_2023_03}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:836-opus-172622}, pages = {16 -- 20}, year = {2023}, abstract = {This review is about where and which tidal power systems are currently deployed. It starts with an insight into the variety of different tidal power systems. With the help of a list from the European Marine Energy Center about currently used systems for tidal power plants, it quickly becomes apparent that two systems stand out. These are the vertical and horizontal turbines. The latter are particularly common, as they are used for both tidal stream and tidal range power plants. Determining the regions with high potential for tidal power is not always easy due to the many influencing factors. Influencing factors are, for example form and conditions of the seabed, topographical features of the coast or currents in the sea [1]. Therefore, each region must be considered separately. n this paper the focus is on the UK, the literature shows that the coastal regions around the UK provide about 50 TWh/year of the European tidal power potential. This is due to the location between the oceans and the geological conditions, which act as a channel for the tides. The two areas with high potential where planning and construction of tidal power plants is currently underway are in the north of Scotland and in the southwest of England in the Bristol Channel.}, language = {en} } @article{Sommer2023, author = {Sommer, Philipp}, title = {Open-Power System Modelling - A Review of Existing Methods and Models}, series = {Educational Journal of Renewable Energy Short Reviews}, journal = {Educational Journal of Renewable Energy Short Reviews}, doi = {10.25974/ren_rev_2023_04}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:836-opus-172636}, pages = {21 -- 26}, year = {2023}, abstract = {This review paper presents a short overview of current power system modelling tools especially used for analysing energy and electricity systems for the supply and demand sector. The main focus of this review lies on open source tools and models which are written and used in the programming language "Python". The modelling tools are represented in a comprehensive table with key information. Five modelling tools with an open source license can be filtered out. The modelling tool PyPSA can be considered as a high performing tool especially as the gap between power system analysis tool (PSAT) and energy system modelling tool.}, language = {en} } @article{Bredehoeft2024, author = {Bredeh{\"o}ft, Claas}, title = {Environmental impacts of tidal power plants - Current status of the environmental impacts of conventional tidal power plants}, series = {Educational Journal of Renewable Energy Short Reviews}, journal = {Educational Journal of Renewable Energy Short Reviews}, doi = {10.25974/ren_rev_2024_01}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:836-opus-176379}, pages = {3 -- 8}, year = {2024}, abstract = {Meanwhile, renewable energy sources such as hydropower, solar and wind energy and biomass are increasingly being used to reduce dependence on fossil fuels and thus counteract the ongoing global warming. However, these are also associated with environmental impacts. To that effect, this article takes a closer look at tidal power plants, which are classified as hydroelectric power plants, by conducting a systematic literature review. The results show that the strength and form of the environmental impact depends on the specific location and type of plant. Tidal power plants have an impact on the habitats of marine animals and thus influence their behavior and population. In addition, the operation of tidal power plants changes the sediment distribution, causes a reduction in current velocities and a change in current direction in the surrounding area and leads to a change in wave height. The construction of the power plants is associated with noise, which primarily causes changes in the behavior of some species. Furthermore, the electromagnetic fields generated can also affect marine life. In order to assess the environmental impact of tidal power plants in comparison to other renewable energies, further studies should focus on the environmental impact of the different technologies in relation to the energy yield.}, language = {en} } @article{Bresgott2024, author = {Bresgott, Jannes}, title = {How can artificial intelligence be used to find areas for wind turbines and solve other challenges associated with wind energy?}, series = {Educational Journal of Renewable Energy Short Reviews}, journal = {Educational Journal of Renewable Energy Short Reviews}, doi = {10.25974/ren_rev_2024_02}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:836-opus-176393}, pages = {9 -- 13}, year = {2024}, abstract = {This article discusses the use of artificial intelligence in the wind energy industry, particularly in addressing challenges and optimizing the expansion of renewable energies in Germany. It highlights the application of artificial intelligence in wind forecasts and yield predictions, bird detection, wind turbine and farm design, condition monitoring, and predictive maintenance. Additionally, it introduces the "WindGISKI" research project, which aims to use artificial intelligence to identify new areas for wind turbines. The project utilizes a neural network to analyze and predict flight routes, potentially reducing bird mortality. The document also emphasizes the potential broader applications of "WindGISKI" in other fields of activity, such as land use planning and city development. Overall, it underscores the significant role of artificial intelligence in addressing challenges in wind energy and outlines the potential for artificial intelligence to drive the expansion of renewable energies while addressing key obstacles.}, language = {en} } @article{Brinkschmidt2024, author = {Brinkschmidt, Florian}, title = {Technologies for structural health monitoring of wind turbine blades - An overview of different techniques}, series = {Educational Journal of Renewable Energy Short Reviews}, journal = {Educational Journal of Renewable Energy Short Reviews}, doi = {10.25974/ren_rev_2024_03}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:836-opus-176401}, pages = {14 -- 21}, year = {2024}, abstract = {Wind turbine structures take a major role in the modern conversion to renewable energy sources and contribute to the creation of a greener world. In recent years, the development and installation of wind turbines have seen rapid growth. However, with the increasing capacity and size of wind farms worldwide, there are growing concerns about the safety and reliability of these installations. Therefore, structural health monitoring and the detection of damage to wind turbines have gained considerable importance in research. Wind turbine blades are particularly susceptible to various types of damage due to environmental influences. This article provides an overview of signal responses, sensors used and non-destructive testing techniques in the field of damage detection on wind turbine blades. The intention of the article is to give an insight into the possibilities of structural health monitoring and at the same time to point out unsolved problems in this field.}, language = {en} } @article{Finke2024, author = {Finke, Tessa}, title = {Drawing up a catalog of criteria for special solutions for fish passages based on the DWA-M 509 leaflet}, series = {Educational Journal of Renewable Energy Short Reviews}, journal = {Educational Journal of Renewable Energy Short Reviews}, doi = {10.25974/ren_rev_2024_04}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:836-opus-176410}, pages = {22 -- 27}, year = {2024}, abstract = {The preservation of water bodies continuity is fundamental for aquatic communities, particularly for fish populations. Various structures impede watercourse continuity, impacting fish migration and habitat distribution. Conventional fish passages often fall short in diverse scenarios, prompting the development of specialized solutions. This article proposes a criteria catalog for these special fish passage solutions based on DWA leaflet DWA-A 509. It discusses the need for these solutions, presents a selection of specialized options, and outlines criteria from DWA-M 509, construction guidelines, and economic perspectives. It scrutinizes criteria ranging from target fish species to cost considerations. Three examples, including the Runserau fish lift, the bristle ramp fish lock, and the Fishcon sluice, illustrate these specialized solutions, their functionalities, advantages, and drawbacks. Additionally, the article compiles criteria from industry standards and guidelines into a comprehensive evaluation catalog. The criteria, when applied, assist in the selection of suitable fish passage solutions based on specific site conditions and fish species requirements. This holistic approach aims to optimize fishway selection, fostering the ecological sustainability of watercourses. However, this catalog remains dynamic and open to expansion with evolving research and practical application, urging further exploration and validation of these criteria through diverse case studies and technological advancements in the field.}, language = {en} } @article{KlemmVennemannWiese2024, author = {Klemm, Christian and Vennemann, Peter and Wiese, Frauke}, title = {Potential-risk and no-regret options for urban energy system design — A sensitivity analysis}, series = {Sustainable Cities and Society}, volume = {102}, journal = {Sustainable Cities and Society}, issn = {2210-6707}, doi = {10.25974/fhms-17568}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:836-opus-175686}, pages = {105189}, year = {2024}, abstract = {This study identifies supply options for sustainable urban energy systems, which are robust to external system changes. A multi-criteria optimization model is used to minimize greenhouse gas (GHG) emissions and financial costs of a reference system. Sensitivity analyses examine the impact of changing boundary conditions related to GHG emissions, energy prices, energy demands, and population density. Options that align with both financial and emission reduction and are robust to system changes are called "no-regret" options. Options sensitive to system changes are labeled as "potential-risk" options. There is a conflict between minimizing GHG emissions and financial costs. In the reference case, the emission-optimized scenario enables a reduction of GHG emissions (-93\%), but involves higher costs (+160\%) compared to the financially-optimized scenario. No-regret options include photovoltaic systems, decentralized heat pumps, thermal storages, electricity exchange between sub-systems and with higher-level systems, and reducing energy demands through building insulation, behavioral changes, or the decrease of living space per inhabitant. Potential-risk options include solar thermal systems, natural gas technologies, high-capacity battery storages, and hydrogen for building energy supply. When energy prices rise, financially-optimized systems approach the least-emission system design. The maximum profitability of natural gas technologies was already reached before the 2022 European energy crisis.}, language = {en} } @article{Kramer2024, author = {Kramer, Kevin}, title = {Water wheels for energy recovery in the outlet of wastewater treatment plants - Using the example of the water wheel at the Warendorf central wastewater treatment plant}, series = {Educational Journal of Renewable Energy Short Reviews}, journal = {Educational Journal of Renewable Energy Short Reviews}, doi = {10.25974/ren_rev_2024_05}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:836-opus-176423}, pages = {28 -- 32}, year = {2024}, abstract = {The annual wastewater flow that is treated by public wastewater treatment plants in Germany amounts to approx. 10 ∗ 10^9 m3/a and forms an "artificial" hydropower potential that can be used for energy generation or recovery. In the context of this paper, energy recovery in the outlet of wastewater treatment plants is examined using the specific example of the water wheel at the Warendorf central wastewater treatment plant. The "artificial" hydropower potential can be roughly estimated at up to 20 to 105 GWh/a , whereby this is largely dependent on the hydraulic gradient. The strong variance results, among other things, from the findings of the water wheel operation in Warendorf. The decisive aspect here is the differential factor, which describes the deviation between the theoretical and actual energy yield of the water wheel. The factor includes maintenance work, downtimes and insufficient inflows, which are associated with a loss of output. In the case study, the annual energy recovery amounts to approx. 2 \% of the annual electricity consumption of the wastewater treatment plant and can be estimated to 23,500 kWh (2022). In the context of the economic analysis, it can be seen that despite the "low" yield, economic operation is possible if the system is viewed as a long-term investment - payback period of the example is approx. 14,5 years. The 27-year operation (1996 - 2023) of the water wheel at the Warendorf central wastewater treatment plant confirms this and important findings on successful practical operation can be shown in the context of this paper.}, language = {en} } @article{Krehenbrink2024, author = {Krehenbrink, Julian}, title = {Comparison of small wind turbines for urban areas, a market analysis}, series = {Educational Journal of Renewable Energy Short Reviews}, journal = {Educational Journal of Renewable Energy Short Reviews}, doi = {10.25974/ren_rev_2024_06}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:836-opus-176430}, pages = {33 -- 40}, year = {2024}, abstract = {This document presents a comparative analysis of horizontal and vertical small wind turbines for urban areas in three power classes up to 10 kW in different categories. The main objective was to conduct a market analysis to assess the marketability of these wind energy systems. The aim was to make it easier for potential customers to make a decision. However, due to the limited availability of data, the project encountered considerable difficulties. As a result, the study became a comparative assessment, which led to results that may not be readily transferable to urban environments, slightly missing the original objective of the study. The results underline the difficulties associated with conducting a comprehensive market analysis in this sector and highlight the need for an independent series of tests under specific conditions. The paper concludes with a plea for future research efforts to adapt data collection methods to urban conditions in order to improve the relevance and applicability of such studies in practice.}, language = {en} } @article{Mueller2024, author = {M{\"u}ller, Hendrik}, title = {Fish mortality at hydropower plants - Protection Measures and Solutions}, series = {Educational Journal of Renewable Energy Short Reviews}, journal = {Educational Journal of Renewable Energy Short Reviews}, doi = {10.25974/ren_rev_2024_07}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:836-opus-176444}, pages = {41 -- 45}, year = {2024}, abstract = {The construction and operation of hydropower plants for energy generation is a major issue in sustainable energy production. Nevertheless, hydropower plants have a negative impact on fish populations. It is crucial to understand the causes and consequences of fish mortality in hydropower plants in order to find sustainable solutions that reconcile the need for energy with the conservation of aquatic ecosystems. This article examines the fish protection measures that can be implemented to reduce fish mortality and maintain ecological balance. Based on the main literature reviewed, this article mainly refers to Germany in terms of studies carried out and hydropower plants.}, language = {en} } @article{Noelken2024, author = {N{\"o}lken, Lukas}, title = {Impact of robotics on the operation and maintenance of offshore wind turbines - A review}, series = {Educational Journal of Renewable Energy Short Reviews}, journal = {Educational Journal of Renewable Energy Short Reviews}, doi = {10.25974/ren_rev_2024_08}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:836-opus-176456}, pages = {46 -- 52}, year = {2024}, abstract = {This article analyses the impact of robotics on the operation and maintenance (O\&M) of offshore wind turbines (OWTs), with a particular emphasis on the challenges and benefits. As the world's reliance on renewable energy, particularly offshore wind, increases to reduce climate change, the growing number of OWTs requires effective O\&M. Challenges consist of logistics, accessibility and high costs. The paper presents the application of climbing robots, unmanned aerial vehicles and underwater robots to overcome these challenges. The combination of multiple robotic platforms, such as autonomous surface vehicles and autonomous underwater vehicles, represents a collaborative approach to O\&M. Obstacles include the need for accurate navigation, building trust between humans and robots, and research into artificial intelligence. In conclusion, the integration of robotics in O\&M presents considerable advantages, increasing efficiency, safety and cost-effectiveness. Further progress and research into artificial intelligence are crucial in achieving complete automation, which will transform the O\&M of OWTs.}, language = {de} } @article{Ortmann2024, author = {Ortmann, Thiark}, title = {Effects of Noise Emissions from Offshore Wind Turbines on the Marine Environment}, series = {Educational Journal of Renewable Energy Short Reviews}, journal = {Educational Journal of Renewable Energy Short Reviews}, doi = {10.25974/ren_rev_2024_09}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:836-opus-176460}, pages = {53 -- 60}, year = {2024}, abstract = {The pursuit of Offshore Wind Energy (OWE), integral to the German government's ambitious renewable energy goals raises concerns about the environmental impact of noise emissions on marine life. This paper delves into the theoretical background of Offshore Wind Turbine (OWT) noise, exploring its various phases from the survey to decommission. It examines the types and causes of noise emissions, their effects on marine wildlife and potential mitigation measures. Highlighting the regulatory framework in Germany, the paper emphasises the need for nuanced approaches to balance renewable energy objectives with marine ecosystem preservation.}, language = {en} } @article{Recker2024, author = {Recker, Luis}, title = {State of the art: Corrosion protection for offshore wind turbines}, series = {Educational Journal of Renewable Energy Short Reviews}, journal = {Educational Journal of Renewable Energy Short Reviews}, doi = {10.25974/ren_rev_2024_10}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:836-opus-176475}, pages = {61 -- 66}, year = {2024}, abstract = {This review paper provides an initial overview of the state of the art of common corrosion protection methods for offshore wind turbines. The functions of the individual corrosion protection methods and their interaction are explained. In addition, the specific corrosion protection of different zones and components of an offshore wind turbine will be discussed. Finally, some information is given on current and possible future developments in this subject area.}, language = {en} } @article{Reintjes2024, author = {Reintjes, Jannis}, title = {Dismantling of wind turbines - An overview of methods}, series = {Educational Journal of Renewable Energy Short Reviews}, journal = {Educational Journal of Renewable Energy Short Reviews}, doi = {10.25974/ren_rev_2024_11}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:836-opus-176481}, pages = {67 -- 72}, year = {2024}, abstract = {This paper outlines the three main areas relevant to dismantling: the rotor blades, hub and nacelle, the tower and the foundation. The paper discusses the dismantling procedures, including the removal of the top structure, the tower and the foundation, and evaluates various methods of dismantling the tower, such as modular dismantling, collapse blasting, folding blasting, wrecking ball demolition and hydraulic ram demolition. The assessment of these methods in practice and the potential challenges and considerations for future dismantling, particularly as wind turbine heights increase, are also addressed.}, language = {en} } @article{Volkmer2024, author = {Volkmer, Philipp}, title = {Technical challenges and trends in upscaling wind turbines - A review}, series = {Educational Journal of Renewable Energy Short Reviews}, journal = {Educational Journal of Renewable Energy Short Reviews}, doi = {10.25974/ren_rev_2024_12}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:836-opus-176492}, pages = {73 -- 78}, year = {2024}, abstract = {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.}, language = {en} } @article{Weisser2024, author = {Weißer, Hannes}, title = {Relevance of Bird Strikes on Wind Turbines in Germany: A Review}, series = {Educational Journal of Renewable Energy Short Reviews}, journal = {Educational Journal of Renewable Energy Short Reviews}, doi = {10.25974/ren_rev_2024_13}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:836-opus-176500}, pages = {79 -- 84}, year = {2024}, abstract = {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.}, language = {en} } @article{Zurhold2024, author = {Zurhold, Roman}, title = {Guidelines for Onshore Repowering in Germany}, series = {Educational Journal of Renewable Energy Short Reviews}, journal = {Educational Journal of Renewable Energy Short Reviews}, doi = {10.25974/ren_rev_2024_14}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:836-opus-176520}, pages = {85 -- 93}, year = {2024}, abstract = {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.}, language = {en} } @article{SieringGruening2023, author = {Siering, Nils and Gr{\"u}ning, Helmut}, title = {Stormwater Tree Pits for Decentralized Retention of Heavy Rainfall}, series = {Water}, volume = {2023 / 15}, journal = {Water}, number = {Water 2023, 15, 2987}, issn = {2073-4441}, doi = {10.25974/fhms-17720}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:836-opus-177201}, pages = {1 -- 16}, year = {2023}, abstract = {Stormwater tree pits with storage elements enable the irrigation of urban trees and can potentially act as decentralized rainwater retention basins. This paper mainly focuses on analyzing this potential. Field tests were conducted to investigate the irrigation behavior and the storage effect of a storm water tree pit system using Perl hoses as irrigation elements over a period of two years. The rainfall, storage volumes, and soil moisture within the employed planting pit were measured. With the help of system modeling, the retention ability of the storm water tree pit system was analyzed. The available storage volume was sufficient to irrigate trees for several days. During the measurement period, about 15\% of the inflowing rainwater was fed to the root zone of the tree. With practical storage volumes of 200 to 300 m3/ha, a remarkable amount of water from heavy rainfall could be completely stored, thus significantly reducing the risk of flooding. The retention effect and irrigation behavior largely depend on the soil conditions and the technical possibilities of the equipment supplying the root area (in this case, Perl hoses). Further investigations are required to determine the influence on the growth conditions of trees and optimize of the system for discharge into the root zone.}, language = {en} } @article{Dresemann2023, author = {Dresemann, Oliver}, title = {Challenges for the construction of an underground hydroelectric power plant with electricity storage (UPSHP) in terms of public acceptance and technical aspects - A Summary}, series = {Educational Journal of Renewable Energy Short Reviews}, journal = {Educational Journal of Renewable Energy Short Reviews}, doi = {10.25974/ren_rev_2023_01}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:836-opus-172607}, pages = {3 -- 7}, year = {2023}, abstract = {For the increasingly important storage of renewably generated electricity, this review explains the construction of a surface and underground pumped storage power plant. The problems for the construction of an underground pumped storage power plant are further listed. These are geological, environmental and economic problems as well as a low acceptance by the population. The geological problems are concerns about leaching of minerals and heavy metals as well as the statics of the cavities. Mining companies in Germany are obligated to renaturalize the landscape areas again, which could be realised by a lake. Furthermore, care must be taken to ensure that the mine water does not come into contact with the groundwater. According to a survey by RISP on the subsequent use of the mine areas for an underground pumped storage power plant, the acceptance of the population is over 70 percent. The economic consideration concludes that the arbitrage profit for a difference between off-peak and peak of 10 €/MWh is about 2.7 M€/a and for 100 €/MWh about 27.3 M€/a. With investment costs of about 630 M€, despite the assumption of 100 €/MWh, more than 20 years are needed for an underground pumped storage power plant to be amortized. The acceptance could be increased by creating a lake as a recreation area as well as being used as an upper storage reservoir. Thus, the cost of renaturation decrease when combined with the creation of the storage basin. The problem of ground conditions can be solved by creating new cavities by means of tunnel boring at an inclination. For static safety as well as against leaching of minerals and heavy metals, the cavity walls can be sealed with reinforced concrete. The technology of underground pumped storage power plants can be used for better utilisation of renewable energies. This is especially in flat and densely populated regions a possibility to store energy, because the main part of the power plant is underground.}, language = {en} }