Purpose Energy scenarios have long been successfully used to inform decision-making in energy systems planning, with a wide range of different methodological approaches for developing and evaluating them. The purpose of this study is to analyze the existing approaches and classify them with a morphological box. Design/methodology/approach This paper builds upon the methodological literature on developing and evaluating energy scenarios and presents a morphological box, which comprises parameters describing the scenario properties, (energy system) model properties, scientific practice and institutional settings of energy scenarios. The newly developed morphological box is applied to four selected energy scenarios of the German energy transition. Findings The morphological box is a suitable tool to classify current energy scenarios. The exemplary application also points toward four challenges in the current practice of energy scenario development and evaluation: increasing complexity of decision problems, transparency of the scenario development process, transparency of the decision support process and communication of uncertainty. Originality/value The morphological box of energy scenarios helps researchers soundly document and present their methodological approaches for energy scenario development and evaluation. It also facilitates the work of analysts who want to classify, interpret and compare energy scenarios from a methodological perspective. Finally, it supports the identification of gaps between current practice and the methodological literature on energy scenarios, leading to the development of new types of energy scenarios.