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- Energie · Gebäude · Umwelt (EGU) (66) (remove)
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.
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.
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.
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.
Die Transformation der Energiesysteme im Rahmen der Energiewende macht diese durch zusätzliche Komponenten und Wechselwirkungen immer komplexer. Das ökonomische und ökologische Potenzial, dass sich aus der Nutzung der Synergien dieser Komponenten ergeben kann, erfordert eine gemeinsame Betrachtung des gesamten Energiesystems hinsichtlich sämtlicher Energie- und Verbrauchssektoren.
Die Energiesystemmodellierung stellt eine geeignete Methode zur Modellierung und Optimierung dieser urbanen Energiesysteme dar. Mit dem „Spreadsheet Energy System Model Generator“ (SESMG) hat die FH Münster ein Open Source Tool entwickelt, das die Betrachtung urbaner Quartiere ermöglicht. Diese können hinsichtlich verschiedener Zielkriterien wie z. B. monetären Kosten und THG-Emissionen optimiert werden. Die tabellenbasierte Eingabe erfordert keine Programmierkenntnisse. Das implementierte Urban District Upscaling Tool erleichtert die effektive Modellierung auch größerer Systeme. Die automatisierte Ergebnisaufbereitung ermöglicht eine schnelle Analyse der Ergebnisse.
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.
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.
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.
The energy demand of the residential sector contributed to about 29 % of Germany’s final energy consumption in 2020. For the planning and optimization of energy systems, an understanding of the temporal energy consumption is necessary. This paper discusses tools for estimating these load profiles. Load profiles for electricity, space heating and domestic hot water (DHW) are investigated. A total of ten tools were applied. It turns out that the selected load profiles are dependent on the field of application. Load profiles influence the results of energy system modeling and therefore it is important to differentiate load profile tools. Standardized load profiles are well suited when a large number of buildings are considered. Stochastic load profiles, behavioral load profiles and the reference load profiles are well suited for building-specific simulations. Physical load pro- files are well suited for single building models, but as soon as several buildings are considered, the input effort for a sufficient accuracy is high.