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EnBW Energie Baden-Württemberg AG, or simply EnBW, is a publicly traded electric utilities company headquartered in Karlsruhe, Germany. Wikipedia.

Heidel B.,University of Stuttgart | Hilber M.,EnBW | Scheffknecht G.,University of Stuttgart
Applied Energy | Year: 2014

The wet flue gas desulfurization process (FGD) in fossil fired power plants offers the advantage of simultaneously removing SO2 and other water soluble pollutants, such as certain oxidized mercury compounds (Hg2+). In order to maximize SO2 removal efficiency of installed FGD units, organic additives can be utilized. In the context of multi-pollutant control by wet FGD, the effect of formic and adipic acid on redox reactions of dissolved mercury compounds is investigated with a continuously operated lab-scale test-rig. For sulfite (SO32-) concentrations above a certain critical value, their potential as reducing agent leads to rapidly increasing formation and re-emission of elemental mercury (Hg0). Increasing chloride concentration and decreasing pH and slurry temperature have been identified as key factors for depressing Hg0 re-emissions. Both organic additives have a negative impact on Hg-retention and cause increased Hg0 re-emissions in the wet FGD process, with formic acid being the significantly stronger reducing agent. Different pathways of Hg2+ reduction were identified by qualitative interpretation of the pH-dependence and by comparison of activation enthalpies and activation entropies. While the first mechanism proposed identifies SO32- as reducing agent and is therefore relevant for any FGD process, the second mechanism involves the formate anion, thus being exclusively relevant for FGDs utilizing formic acid as additive. © 2013 Elsevier Ltd. Source

The Iffezheim hydropower plant was commissioned in 1978. Due to it being designed for approximately 180 days of exceedance, the plant was predestined to be extended by a 5th unit right from the beginning. Several attempts to start planning failed because of the profitability of such a project, which became possible only in the wake by the German Renewable Energy Act for large-scale hydropower plants. After two planning phases that were very difficult, the construction of the 5th turbine was launched in the beginning of 2009. Not only was the realisation of the building pits in extremely small spaces very complex, but there were also various problems that had considerable repercussions on the time of construction and the execution of construction work. Unusual solutions in the unit's technology finally led to a successful result, which fully met the expectations in terms of production and availability. Source

Adams Z.,European Union | Gerner M.,EnBW
Energy Economics | Year: 2012

This paper investigates the cross hedging performance of several oil forwards contracts using WTI, Brent, gasoil and heating oil to manage jet-fuel spot price exposure. We apply three econometric techniques that have been widely tested and applied in the cross hedging literature on foreign exchange and stock index futures markets. Using quotes from the financial industry on forward contracts, we can show that the optimal cross hedging instrument depends on the maturity of the instrument's forwards contract. The results highlight that the standard approach in the literature to use crude oil as a cross hedge is not optimal for time horizons of three months or less. By contrast, for short hedging horizons our results indicate that gasoil forwards contracts represent the highest cross hedging efficiency for jet-fuel spot price exposure, while for maturities of more than three months, the predominance of gasoil diminishes in comparison to WTI and Brent. © 2012 Elsevier B.V. Source

Schlechtingen M.,EnBW | Santos I.F.,Technical University of Denmark
Applied Soft Computing Journal | Year: 2014

This paper is part two of a two part series. The originality of part one was the proposal of a novelty approach for wind turbine supervisory control and data acquisition (SCADA) data mining for condition monitoring purposes. The novelty concerned the usage of adaptive neuro-fuzzy interference system (ANFIS) models in this context and the application of a proposed procedure to a wide range of different SCADA signals. The applicability of the set up ANFIS models for anomaly detection was proven by the achieved performance of the models. In combination with the fuzzy interference system (FIS) proposed the prediction errors provide information about the condition of the monitored components. Part two presents application examples illustrating the efficiency of the proposed method. The work is based on continuously measured wind turbine SCADA data from 18 modern type pitch regulated wind turbines of the 2 MW class covering a period of 35 months. Several real life faults and issues in this data are analyzed and evaluated by the condition monitoring system (CMS) and the results presented. It is shown that SCADA data contain crucial information for wind turbine operators worth extracting. Using full signal reconstruction (FSRC) adaptive neuro-fuzzy interference system (ANFIS) normal behavior models (NBM) in combination with fuzzy logic (FL) a setup is developed for data mining of this information. A high degree of automation can be achieved. It is shown that FL rules established with a fault at one turbine can be applied to diagnose similar faults at other turbines automatically via the CMS proposed. A further focus in this paper lies in the process of rule optimization and adoption, allowing the expert to implement the gained knowledge in fault analysis. The fault types diagnosed here are: (1) a hydraulic oil leakage; (2) cooling system filter obstructions; (3) converter fan malfunctions; (4) anemometer offsets and (5) turbine controller malfunctions. Moreover, the graphical user interface (GUI) developed to access, analyze and visualize the data and results is presented. © 2013 Elsevier B.V. All rights reserved. Source

Kohler W.R.,EnBW
Theory and Decision | Year: 2011

This article investigates how subjects determine minimum selling prices for lotteries. We design an experiment where subjects have at every moment an incentive to state their minimum selling price and to adjust the price, if they believe that the price that they stated initially was not optimal. We observe frequent and sizeable price adjustments. We find that random pricing models cannot explain the observed price patterns. We show that earlier prices contain information about future price adjustments. We propose a model of Stochastic Pricing that offers an intuitive explanation for these price adjustment patterns. © 2009 Springer Science+Business Media, LLC. Source

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