Methods and tools

The main tools of EEG are energy-system models that have a process-oriented representation of the energy system. However, the multi-dimensionality complexity of the energy transition requires additional tools such as models to assess energy markets impacts, or broader socioeconomic impacts. Given also that the climate change mitigation is a global problem, national energy models need also to be complemented by regional and global models.  To support the group's modeling activities, EEG is a member of the Energy Technology Systems Analysis Programme (ETSAP) of the International Energy Agency (IEA). 


The "model orbit" of the Energy Economics Group has in its core the Swiss TIMES Energy System model (STEM). STEM is a powerful tool to assess energy transition pathways for Switzerland, because it combines long-term horizon, with high intra-annual resolution, and advanced representation of all energy system sectors and technologies. 

STEM is supported by a suite of models, which are also stand alone tools. The JRC EU TIMES model represents in detail the energy systems of 36 European countries, and it is also used to assess the interactions between the Swiss energy system with the European one. GMM is a global energy system model representing 15 (or 17, depending on its configuration), world regions. It is a bottom-up model with high technical details. MERGE-ETL is an Integrated Assessment Model, capturing the interactions between the economic, energy and climate systems. It is a global model, but it also has a representation of Switzerland. SEED is an agent-based model for Switzerland, linked to STEM to provide energy service demands and consumer choices on energy consumption and technology investment which are often not only cost-driven. And, BEM is an electricity and gas market model, which represents the market interactions between the main players in Switzerland and its neighboring countries.  

In addition, the group has established partnership with many international and Swiss teams, including among others ETH-ESA, ETH-FEN, TEP Energy, E3Modelling, and Cambridge Econometrics, while it leverages collaboration and expertise of the Technology Assessment and Risk and Risk Human Reliability groups of LEA.   

EEG ModelOverview.png

The main tools of EEG comprise energy-system models. This type of model refers to a process-oriented representation of the energy system with technological detail. The energy-system models used by EEG are from the MARKAL (MARKet ALlocation) and TIMES (The Integrated MARKAL EFOM System) family of models (Fishbone et al., 1981; Loulou et al., 2005), a group of perfect-foresight, energy-system optimization models that represent current and potential future energy technologies. Such models are typically used to determine the least-cost configuration of the energy system for a given time horizon under a set of assumptions about end-use demands, technology characteristics and resource potentials. In addition to energy-system models, EEG continues to develop and apply MERGE-ETL, an integrated assessment model (Kypreos 2007a,b; Marcucci and Turton 2012).

The models currently used at EEG are as follows:

In the Swiss TIMES energy system model (STEM), the full energy system is depicted from resource supply to end-use energy service demands (ESDs), such as space heating, mechanical processes, and personal/freight transport. The model represents a broad suite of energy and emission commodities, technologies and infrastructure as illustrated in the reference energy system below. The model also combines a long time horizon (2010-2100) with an hourly representation of weekdays and weekends in three seasons. 

Discover more here


EUSTEM is a multiregional electricity model of Europe. It is an extension of the Cross border Swiss TIMES electricity model (CRoSSTEM), by extending the geographical scope to include wider EU electricity markets (as shown in Figure). The model covers 90% of the total installed capacity and 95% of the total electricity generation of EU-28 + Switzerland and Norway.

Discover more here.


The global multi-regional MARKAL (GMM) model provides a long-term (2100) bottom-up representation of the global energy system, with a detailed representation of energy supply technologies and an aggregate representation of demand technologies. The model has recently been disaggregated into 15 world regions. 


PSI's Global Multi-regional MARKAL (GMM) model is extended by the integration of Multi-criteria Decision Analysis (MCDA) indicators.

More information is provided on the GMM-MCDA project website.


MERGE-ETL is an integrated assessment model combining a bottom-up description of the energy system disaggregated into electric and non-electric sectors, a top-down model based on a macroeconomic production function, and a simplified climate cycle. 

Discover more here.


To model the behavior of players in the European electricity markets, we use bi-level market models.

Discover more here.


See Model documentation and publications for details


The model's purpose is to quantify digitalization's impact on technology investment choices, energy consumption and emissions on different energy sectors.

Discover more here.


To model the optimization of dispatch of pumped-storage plant against exogenous electricity prices, we apply stochastic optimal control theory.

See Model documentation and publications for details


The Swiss MARKAL model (SMM) is a bottom-up energy system model depicting in detail the full Swiss energy system to 2050, including a high-level of end-use technology detail in the residential and transportation sectors (Schulz et al. 2007, 2008; Weidmann et al. 2012). This model was originally developed jointly with the University of Geneva (LABRIET, 2003) and subsequently developed independently by EEG. 

Discover more here.


The European, multi-regional energy-conversion MARKAL (EuroMM) model was built within the framework of the EU-sponsored ADAM project (Reiter 2010; Reiter et al. 2011). The EuroMM model provides a multi-regional representation of the energy-conversion sector of the EU-29 countries (EU-27+Norway+Switzerland) aggregated in 18 regions.

Discover more here.


As part of collaborative project activities, EEG has been involved in coupling energy-system models to macro-economic models from other partners (e.g. general equilibrium models). Currently, efforts are underway to develop methodologies for linking the electricity sector models STEM-E and CROSSTEM to the macro-economic models GENESwIS and GEMINI-E3, in collaboration with the Research Lab on the Economics and Management of the Environment (REME) at EPFL and Econability (an economic consultancy) in the framework of the ELECTRA project. Previously, the group collaborated with REME to link the residential and transportation sectors of the Swiss MARKAL model with the macro-economic model GEMINI-E3 as part of NCCR Climate (and earlier projects with the Federal Office of Environment) (Sceia et al. 2009a,b, 2012). These coupling actitivies aim to incorporate macro-economic feedbacks while maintaining technological resolution.