Browsing by Author "Härdtlein, Marlies"

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    Bilanz und Perspektiven der Holzenergienutzung in Baden-Württemberg
    (2006) Eltrop, Ludger; Moerschner, Johannes; Härdtlein, Marlies; König, Andreas
    Für Baden-Württemberg mit rund 14.000 km² Wald auf etwa 39 % der Landesfläche kann die energetische Nutzung von Holz aus ökologischen, ökonomischen und strukturellen Gründen eine wichtige Rolle bei der Entwicklung einer nachhaltigen Forst- und Energiewirtschaft spielen. Die Analyse der Potentiale, die für die Holzenergienutzung in Baden-Württemberg zur Verfügung stehen, hat ergeben, dass ausreichende Mengen des Rohstoffes Holz zur Verfügung stehen. Die Gesamtmenge an Waldholz hat sich nach den Ergebnissen der Waldinventur 2002 trotz verstärkter Nutzung und Sturmkalamitäten sogar weiter vergrößert. Die Berechnungen der vorliegenden Untersuchung haben darüber hinaus deutlich gemacht, dass die Menge an frei verfügbarem Holz in Baden-Württemberg derzeit nicht limitierend ist, um z.B. den Anteil der Holzenergie am Ausbauziel der Verdoppelung des Anteils Erneuerbarer Energien am Primärenergiebedarf in Baden-Württemberg sicherzustellen.
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    A plant‐specific model approach to assess effects of repowering measures on existing biogas plants: the case of Baden‐Wuerttemberg
    (2018) Güsewell, Joshua; Härdtlein, Marlies; Eltrop, Ludger
    Up to the latest versions of the German renewable energy act (EEG), there had been a constant growth of new biogas plants (BGPs). After reaching a stagnation in the last years, today the focus has shifted to improving the existing BGPs. Assuming that most plants have not reached the technical end of life, the question arises on how an operation can be realized beyond the initial EEG support period of 20 years. In addition, new legal and economic conditions require the implementation of adjustments, that is, “repowering measures.” Based on a method review, a plant‐specific model approach is presented to assess repowering measures for a wide range of BGPs differing in capacity, substrate mixture and agricultural structures. The techno‐economic model includes different performance indicators like levelized cost of electricity (LCOE) and temporal aspects like technical progress. Using a data set for BGPs in the state of Baden‐Wuerttemberg (Germany), results are illustrated for the different model modules and three repowering scenarios of an extended operation period of ten years. The scenarios regard different options to meet the requirements of the current EEG, namely the flexibilization and restrictions on energy crops, in comparison with a reference case. While in repowering scenarios, the number of plants decreases between 54% and 69% and the overall power capacity changes between -48% and 13% until 2035. The results further show a reduction potential in the specific area demand and GHG emission up to 12% and 24%, respectively. Technical progress, additional revenues and capacity premiums are shown to be an important factor for efficient substrate utilization, low LCOE and thereby the enabling of an extended operation period. The scenario results indicate that the agricultural areas for energy crop cultivation and the amount of manure used in BGPs will be reduced considerably, inducing new chances and challenges in the future.