Nexus-e: Simulation Framework and Interfaces

Policy changes in the energy sector result in wide-ranging implications throughout the entire energy system and influence all sectors of the economy. Due partly to the high complexity of combining separate models, few attempts have been undertaken to model the interactions between the components of the energy-economic system. The Nexus-e Integrated Energy Systems Modeling Platform aims to fill this gap by providing an interdisciplinary framework of modules that are linked through well-defined interfaces to holistically analyze and understand the impacts of future developments in the energy system. This platform combines bottom-up and top-down energy modeling approaches to represent a much broader scope of the energy-economic system than traditional stand-alone modeling approaches. In Phase 1 of this project, the objective is to develop a novel tool for the analysis of the Swiss electricity system. This study illustrates the capabilities of Nexus-e in answering the crucial questions of how centralized and distributed flexibility technologies could be deployed in the Swiss electricity system and how they would impact the traditional operation of the system. The aim of the analysis is not policy advice, as some critical developments like the European net-zero emissions goal are not yet included in the scenarios, but rather to illustrate the unique capabilities of the Nexus-e modeling framework. To answer these questions, consistent technical representations of a wide spectrum of current and novel energy supply, demand, and storage technologies are needed as well as a thorough economic evaluation of different investment incentives and the impact investments have on the wider economy. Moreover, these aspects need to be combined with modeling of the long- and short-term electricity market structures and electricity networks. This report illustrates the capabilities of the Nexus-e platform. The Nexus-e Platform consists of five interlinked modules: 1. General Equilibrium Module for Electricity (GemEl): a computable general equilibrium (CGE) module of the Swiss economy, 2. Centralized Investments Module (CentIv): a grid-constrained capacity expansion planning module considering system flexibility requirements, 3. Distributed Investments Module (DistIv): a generation expansion planning module of distributed energy resources, 4. Electricity Market Module (eMark): a market-based dispatch module for determining generator production schedules and electricity market prices, 5. Network Security and Expansion Module (Cascades): a power system security assessment and transmission system expansion planning module. A novelty of the Nexus-e platform is that it combines the core modules with automated interfaces to pass all necessary information between modules. The data transfer process within each interface is completely automated in code (hard-linked). The combined process and interfaces are designed to be modular and customizable so that different combinations of modules could be used together in future analyses. This report provides the description and documentation for all the interfaces along with the overall simulation process.