  In this paper, we explore centralized and more decentral approaches to
succeed the energiewende in Germany, in the European context. We use the AnyMOD
framework to model a future renewable-based European energy system, based on a
techno-economic optimization, i.e. cost minimization with given demand,
including both investment and the subsequent dispatch of capacity. The model
includes 29 regions for European countries, and 38 NUTS-2 regions in Germany.
First the entire energy system on the European level is optimized. Based on
these results, the electricity system for the German regions is optimized to
achieve great regional detail to analyse spatial effects. The model allows a
comparison between a stylized central scenario with high amounts of wind
offshore deployed, and a decentral scenario using mainly the existing grid, and
thus relying more on local capacities. The results reveal that the cost for the
second optimization of these two scenarios are about the same: The central
scenario is characterized by network expansion in order to transport the
electricity from the wind offshore sites, whereas the decentral scenario leads
to more photovoltaic and battery deployment closer to the areas with a high
demand for energy. A scenarios with higher energy efficiency and lower demand
projections lead to a significant reduction of investment requirements, and to
different localizations thereof.
