Energy scenarios are developed to provide decision support in the energy sector or in energy policy. In this context, scenario planning and multi-criteria decision-making can complement energy system analysis for identifying and evaluating transition paths toward a sustainable energy supply system. This presentation focuses on aspects of multi-criteria analysis within a case study on the transition of the electricity sector in Lower Saxony, Germany, to energy from renewable sources (Dumeier et al. 2019; Witt et al. 2020). We enhance the MCA method PROMETHEE (Brans and Smet 2016) for the evaluation of long-term transition paths and suggest a multi-period problem formulation. To identify and quantify the environmental impacts of electricity generation in Lower Saxony until 2050 selected LCA impact categories have been calculated for (a) local power generation with flexible energy demand and a focus on onshore wind power and rooftop PV and (b) large-scale storage and power generation with a focus on offshore wind power and ground-mounted PV.