National Energy System Model with Focus on Intersectoral System Development



Study | Fraunhofer ISE | Februar 2020

Paths to a Climate-Neutral Energy System

The German Energy Transition in its Social Context

© Fraunhofer ISE
Scheme of the energy system as presented in the simulation model of REMod.

Focus of analysis

  • Cost optimised structural development of greenhouse gas neutral national energy systems
  • Future market shares and technology trends
  • Technology-specific operation modes based on interactions between different application sectors
  • Sector coupling technologies such as electric vehicles or electric heat pumps and their influence on the structural system development

Background of model application

To achieve its climate protection targets, the German federal government has declared to transform its energy system. Therefore, a fundamental restructuring of the energy system as we know it today is necessary.

How can a cost-optimised transformation of a national energy system – with consideration of all energy carriers and consumer sectors – be achieved in line with meeting the declared climate targets and ensuring a secure energy supply at all times? By running customized scenario-based simulations the REMod model is most suitable to answer specific questions concerning the transformation of a national energy system.  In repeated cooperation with federal and state ministries, international research institutions and above all through the close exchange with industrial customers, the applicability as a strategic consulting tool was proven and the model is continuously further developed.

Characteristics of the model

The basic functionality of the REMod model is based on a cost-based (non-linear) optimisation of a national energy supply system, whose energy-related CO2 emissions do not exceed a specified target value and/or target pathway. The optimisation target is to dimension all generators, stores, converters, and consumers at minimum costs such that the energy balance of the overall system is met in every hour from today to 2050. Each technological property can be displayed in any level of detail. For example, different charging strategies for battery-electric vehicles or the interaction of thermal storage and different heating systems can be modelled as realistically as possible. In addition to ecological sustainability and cost-effectiveness, the model also takes account of security of supply through a high level of technical detail and temporal resolution, which reconciles energy supply and demand at all times throughout the year.

The following characteristics describe the REMod model

  • Technical focus: Description of the interaction between the energy sectors electricity, heat, mobility and industry on the transformation path from today until 2050
  • Goal: Determine the cost-optimal transformation of a national energy system until the year 2050 and achieve the defined reduction of greenhouse gas emissions.
  • Type of energy system model: Technical, bottom-up energy system model with dynamic, non-linear optimisation of expansion planning for lowest possible costs.
  • Geographical coverage: national (e.g. Germany)
  • Temporal resolution: Hourly from 2014 (calibration) to 2050
  • All sectors: Demand, generation, storage, energy conversion, demand-side-management
  • Framework conditions: Meeting a defined reduction of greenhouse gas emissions
  • Dealing with uncertainty: Sensitivity analyses e.g. different scenario calculations
  • Programming language: Delphi/Python, Solver: Particle Swarm Optimisation (PSO)



  • Energy service providers
  • Industry
  • Policy makers
  • Public utilities