Erweiterung der Flexibilität von Biogasanlagen – Substratmanagement, Fahrplansynthese und ökonomische Bewertung

Since the amendment of the German Renewable Energy Act (EEG) in 2012 as well as in the current version (EEG 2014) the parameters for the expansion of renewable energies aim for a stronger market integration of those. Thereby, biogas plants represent a promising option to produce demand-driven energy to compensate differences between energy demand and energy supply caused by irregular sources (e. g. wind and solar). The contribution focuses on the economic assessment of the flexible biogas production by specific feeding in comparison to continuous gas production against the background of a flexible conversion of biogas into electrical power. The required additional demand for gas storage capacity of a model biogas plant is determined by combinations of different feeding regimes and by three optimised power generation schedules. Subsequently, a cost-benefit analysis is conducted to assess the substrate management economically. The developed methodology is especially designed for existing plants and is used for assessing a multi-factorial substrate management as flexibility option. The results show that substrate management is increasingly appropriate to reduce the additional demand for gas storage especially for longer-term planning horizons (above 12 h) regarding schedule organisation. Moreover, the flexible operation allows generating higher marketing revenues on the European Power Exchange (EPEX Spot SE) at low additional costs.