Energy System Uncertainty Catalog A structured catalog of uncertainties for energy-system modelling, covering parametric, structural, and temporal uncertainties across renewable energy, heat, bioenergy, Power-to-X/hydrogen, storage, imports, grid infrastructure, and demand sectors. The catalog is designed to support uncertainty analysis, sensitivity analysis, scenario development, and model robustness assessment in integrated energy-system models. Overview Energy-system models are affected by multiple sources of uncertainty, including uncertain technology costs and potentials, modelling assumptions, system constraints, demand evolution, and weather-dependent time series. However, these uncertainties are often treated inconsistently across studies. This repository provides a structured and traceable catalog of relevant uncertainty parameters that can be used to systematically identify and characterize uncertainty in energy-system models. The catalog distinguishes between three main uncertainty classes: Parametric uncertainty — uncertainty in numerical model inputs such as investment costs, technology efficiencies, capacities, potentials, and technical parameters. Structural uncertainty — uncertainty arising from modelling choices, system representation, constraints, optimization assumptions, and technology inclusion/exclusion. Temporal uncertainty — uncertainty associated with weather years, demand profiles, time series, and other time-dependent model inputs. Catalog Structure The main catalog is provided as an Excel workbook: Uncertainty Catalog.xlsx The workbook contains the following sheets: Main Provides an overview of the uncertainty classification and technology categories used throughout the catalog. Parametric Contains numerical model parameters and their associated uncertainty ranges. Each parameter includes information such as: Field Description ID Unique uncertainty identifier Parameter Parameter name Technology Category Relevant technology or sector Model Component Specific model component Sector Electricity, heat, gas, etc. Unit Parameter unit Baseline Reference value Lower Bound Lower uncertainty boundary Upper Bound Upper uncertainty boundary Uncertainty Type Epistemic, aleatory, or mixed Reference Plot Location of supporting reference data Source / Reference Literature and data sources Justification Rationale for the selected uncertainty range Description Interpretation of the parameter Parameter Name in Model Corresponding model variable Structural Contains uncertainties associated with the formulation and structure of the energy-system model. Examples include: Temporal resolution CO₂ constraints Grid losses Storage operating assumptions Optimization approach Penalty costs Technology inclusion/exclusion Alternative system configurations Temporal Contains uncertainties related to time-dependent inputs and scenarios, including: Wind generation profiles Rooftop PV profiles Open-field PV profiles Solar-thermal generation Electricity demand Heat demand Gas demand The catalog distinguishes between aleatory uncertainty, such as interannual weather variability, and mixed uncertainty, where both variability and modelling assumptions contribute. Sources Contains the literature and other sources used to derive or justify the uncertainty ranges. Reference plot Contains the reference information used to derive selected numerical uncertainty ranges for technology parameters.