Netzdienlicher Handel als Element des zellulären Energiesystems am Beispiel des Altdorfer Flexmarkts (ALF)

Der Beitrag erläutert auf Grundlage von beschriebenen Marktmechanismen, welche im Rahmen des Projekts C/sells für ein zelluläres Energiesystem entwickelt werden, die Wertversprechen von Flex-Plattformen für den netzdienlichen Handel von Flexibilität. Diese stellen Netzbetreibern ein zukünftiges Werkzeug für marktbasiertes Engpassmanagement zur Verfügung. Hierzu werden die Funktionen des C/sells Flex-Plattform Konzepts sowie die Interaktionen der beteiligten Akteure vorgestellt. Anschließend werden Charakteristika des Altdorfer Flexmarkts (ALF) als eine Implementierung des Flex-Plattform Konzepts detailliert beschrieben. Auf Basis der Systemlandschaft werden spezifische Prozessschritte erläutert und auf die Schwerpunkte bei der Umsetzung von ALF eingegangen. Hierzu gehört neben dem einfachen Marktzugang von Kleinanlagen die Integration in die durch intelligente Messsysteme bereitgestellte Infrastruktur. In der Zusammenfassung werden die Inhalte im energiewirtschaftlichen Kontext verortet und ein Ausblick auf die weitere Umsetzung gegeben

Infrasound as a cue for seabird navigation

Seabirds are amongst the most mobile of all animal species and spend large amounts of their lives at sea. They cross vast areas of ocean that appear superficially featureless, and our understanding of the mechanisms that they use for navigation remains incomplete, especially in terms of available cues. In particular, several large-scale navigational tasks, such as homing across thousands of kilometers to breeding sites, are not fully explained by visual, olfactory or magnetic stimuli. Low-frequency inaudible sound, i.e., infrasound, is ubiquitous in the marine environment. The spatio-temporal consistency of some components of the infrasonic wavefield, and the sensitivity of certain bird species to infrasonic stimuli, suggests that infrasound may provide additional cues for seabirds to navigate, but this remains untested. Here, we propose a framework to explore the importance of infrasound for navigation. We present key concepts regarding the physics of infrasound and review the physiological mechanisms through which infrasound may be detected and used. Next, we propose three hypotheses detailing how seabirds could use information provided by different infrasound sources for navigation as an acoustic beacon, landmark, or gradient. Finally, we reflect on strengths and limitations of our proposed hypotheses, and discuss several directions for future work. In particular, we suggest that hypotheses may be best tested by combining conceptual models of navigation with empirical data on seabird movements and in-situ infrasound measurements

Constrained Optimization as the Allocation Method in Local Flexibility Markets

Local flexibility markets or smart markets are new tools used to harness regional flexibility for congestion management. In order to benefit from the available flexibility potential for grid-oriented or even grid-supportive applications, complex but efficient and transparent allocation is necessary. This paper proposes a constrained optimization method for matching the flexibility demand of grid operators to the flexibility supply using decentralized flexibility options located in the distribution grid. Starting with a definition of the operational and stakeholder environment of smart market design, various existing approaches are analyzed based on a literature review and a resulting meta-analysis. In the next step, a categorization of the allocation method is conducted followed by the definition of the optimization goal. The optimization problem, including all relevant input parameters, is identified and formulated by introducing the relevant boundary conditions and constraints of flexibility demand and offers. A proof of concept of the approach is presented using a case study and the Altdorfer Flexmarkt (ALF) field test within the project C/sells. In this paper, we analyze the background of the local flexibility market, provide the methodology (including publishing the code of the matching mechanism), and provide the results of the field test

Methylene-bridged bimetallic α-diimino nickel(ii) complexes: synthesis and high efficiency in ethylene polymerization

A series of 1,2-bis(arylimino)acenaphthylidenes (L1-L5) and their corresponding 4,4′-methylenebis(1-(2,6-diisopropylphenylimino)-2- (arylimino)acenaphthylene) derivatives (L6-L10) were synthesized and used to form mono-nuclear nickel bromides LnNiBr2 (n = 1-5, Ni1-Ni5) and bi-nuclear nickel halides LnNi2X4 (n = 6-10: X = Br, Ni2-1-Ni2-5; n = 4, X = Cl, Ni2-6). All the organic compounds were fully characterized by FT-IR spectra, NMR measurements and elemental analysis. The nickel complexes were characterized by FT-IR spectra and elemental analysis and the molecular structures of the representative complexes Ni1, Ni2-1 and Ni2-3 were confirmed by single-crystal X-ray diffraction. Upon activation with either Et2AlCl or MAO, all the nickel complex pre-catalysts exhibited high activity toward ethylene polymerization over the temperature range from ambient to 50 °C. In general, the bi-nuclear complexes showed a positive synergetic effect with higher activity than their mono nuclear analogs. The resultant polyethylene possessed higher molecular weight and a high degree of branching. © 2013 The Royal Society of Chemistry