The Integrated MARKAL-EFOM System – Model generator for energy systems

TIMES as model generator

General Information

For modelling energy systems or parts of them,  TIMES (The Integrated Markal Efom System) has proven to be a process analytical, dynamic and optimizing model generator.  TIMES has been developed within the "Energy Technology Systems Analysis Programme" (ETSAP)1,2. ETSAP has been one of the longest running technology-related co-operation programme in the International Energy Agency (IEA). You can find further information on the ETSAP web page.

Remme, U; Goldstein, G; Schellmann, U; Schlenzig, C. (2001): MESAP/-TIMES - Advanced decision support for energy and environmental planning. In: Chamoni P., Leisten R., Martin A., Minnemann J., Stadtler H. (eds) Operations Research Proceedings 2001 (Selected Papers of the International Conference on Operations Research (OR 2001) Duisburg, September 3–5, 2001), Springer, Berlin/Heidelberg.
IEA-ETSAP (2002): Contributing to the Kyoto Protocol, Summary of Annex VII (1999-2002).


TIMES enables an identification of cost optimal paths towards an energy transformation within the framework of technical and ecological restrictions. With TIMES, an energy system is being mapped in-depth as a network of processes (e.g. types of power plants, traffic technologies) and goods (energy carriers and forms or material) in the shape of a so called reference energy system. With the optimization, we normally specify the initial power plant portfolio, the future development of the cost price and the energy demand as well as relevant parameters for characterizing technologies and energy carriers.

A partial result of the optimization is the outline of the technology portfolio, i.e. type and capacities of the technologies, their dispatch as well as the required energy input, differentiated by energy carriers. By an integrated examination of the energy system areas electricity, heat and mobility as well as associated actors and consumers, an analysis of efficient technology combinations as well as an observation of the interactions in the energy system can take place. 


Further development

We especially emphasize the development of methodological expansion as well as new model approaches regarding future supply and important questions.

TIMES models developed at IER

TIMES Local highlights the investigation of cities or quarters. This includes modelling the regulatory framework in terms of taxes, cost allocations and remuneration for network feed-in and intrinsic consumption of electricity. Here the model takes regard of the sectors public electricity and heat supply, private households, trade, industry, services, transport, manufacturing industry and the import of energy sources. Regarding the buildings sector the model differentiates between six different types of residential buildings (three for building stock and new buildings). Furthermore, the sector industry, trade and services it divided into smaller and larger consumers. The transport sector differentiates between short and long distances in the motorized private transport, and public transport or commercial transport. Regarding electricity and heat supply, the focus lies on modelling grid-related supply capacities in combination with renewables like solar-thermal local heat supply or the integration of sewage heat pumps into the energy system. The use of waste heat or biomass offers potential both for a supply based upon locally available resources as well as a sector specific annex of solar plants. The public electricity supply has access to a technological portfolio of combined heat and power plants, water power, photovoltaics or wind. Additionally, the local energy can also be supplied by electricity imports from overlapping medium-high-voltage power grids.  

As an energy system model, TIMES-D contains the demand sectors manufacturing industry, trade and services, households, agriculture and transport for Germany. Besides the demand sectors, it also displays the technological aspect of energy supply as well as the conversion sector. The system-optimal allocation of scarce resources with simultaneously taking regard of possible interdependencies within the conversion paths and, on the other hand, the possible mapping of competition between technological alternatives is a clear advantage of considering the overall energy system. Furthermore, the energy system model can record adjustment effects in the demand sectors regarding price signals or other energy economic and energy political determining factors. Thus, we can model-endogenously determine changes in the aggregated load profile through demand changes (e.g. by e-mobility).  


Haasz, T. (2017): Entwicklung von Methoden zur Abbildung von Demand Side Management in einem optimierenden Energiesystemmodell : Fallbeispiele für Deutschland in den Sektoren Industrie, Gewerbe, Handel, Dienstleistungen und Haushalte, Forschungbericht Band 131, Institut für Energiewirtschaft und Rationelle Energieanwendung (IER). Universität Stuttgart.

Welsch, J. (2018): Modellierung von Energiespeichern und Power-to-X im deutschen und europäischen Energiesystem, Forschungsbericht Band 136, Institut für Energiewirtschaft und Rationelle Energieanwendung (IER). Universität Stuttgart.

TIMES Actors Model is a technology oriented, linear optimisation model representing the complete German energy system, divided into modules for households, manufacturing industry, energy supply, transport services and other sectors. The actors’ heterogeneity is integrated in the model in order to receive insights into the roles of certain groups of actors. There is, for example a bottom-up-characterisation of the actors within an industrial branch on the basis of production technology and capacity to enable a definition of “actors’ groups”, whose decisions on operation and investments into different production technologies and customer generation technologies are represented more clearly. In ever module, the display of “actors’ groups” includes technological details to enable a proper mapping of conversion possibilities.

The model distinguishes between actors’ groups specific investment options for retrofitting, best available technologies, innovative technologies with a high decarbonisation potential as well as investment options for distributed energy production. This helps to understand the actors’ contributions to the energy transition process. Additionally, the model takes regard of energy source prices regarding the different actors’ groups. The modules are connected to each other via a data link, so that an overall system balance can be identified.

The Pan-European TIMES energy system model (in short: TIMES PanEU) Das Pan-Europäische TIMES Energiesystemmodell (kurz TIMES PanEU) is an energy system model comprising 30 regions, containing all states of EU-27 as well as Switzerland, Norway and the United Kingdom. The function of this model is to time integrally minimise the overall discounted system costs for the time horizon 2010 to 2050. The model assumes a competition between different technologies or energy conversion paths. As an energy system model, on a national level, TIMES PanEU contains all sectors concerned with energy supply and demand, such as raw material supply, public and industrial electricity and heat generation, manufacturing industry, trade, business, service, households and transport. Both greenhouse gas emissions (CO2, CH4, N2O) as well as polluting emissions (CO, NOX, SO2, NH3, NMVOC, PM10, PM2.5) are measured in TIMES PanEU.


Belsl, M. (2014): Kraft-Wärme-Kopplung im Wärmemarkt Deutschlands und Europas – eine Energiesystem- und Technikanalyse, Forschungbericht Band 120, Institut für Energiewirtschaft und Rationelle Energieanwendung (IER). Universität Stuttgart.

Korkmaz, P., Montenegro, R, Schmid, D., Blesl, M., Fahl, U. (2020): On the Way to a Sustainable European Energy System: Setting Up an Integrated Assessment Toolbox with TIMES PanEU as the Key Component, Energies, 13(3), 707.

TIAM IER Model is a global energy system model analysing possible paths towards international climate goals. Based upon the „World Energy Balances“ of the International Energy Agency (IEA) the energy supply structure for 16 world regions as in 2015 can be recorded. Moreover, the energy demand per region can be broken down into 42 energy services with additional drivers, such as population growth or GDP development and be projected as far as into the year 2100. The model covers a detailed display of energy, which examines the y resources, their conversion and transport, and the sectors agriculture, manufacturing industry, trade, services, households and transport. As an Integrated Assessment Model, TIAM can process additional modules: First, for example, the macro-economic CGE model MACRO which examines the economic impacts of different climate paths. Secondly, the global temperature rise can be directly depicted by the emissions derived from the model, also regarding LULUFC emissions, and this shows the impacts of different climate paths.


Mousavi, B., Blesl, M. (2018): Analysis of the relative roles of supply-side and demand-side measures in tackling the global 1.5°C target, In: Giannakidis G., Karlsson, K., Labriet, M., Ó Gallachóir, B. (eds.) Limiting Global Warming to Well Below 2°C: Energy System Modelling and Policy Development, Lecture Notes in Energy, Vol. 64, Springer, Cham.

TIMES Power System Model for Brazil is a newly developed application of the TIMES model generator focusing the integration of SCP into the Brazilian energy system with a high share of renewables. It covers four regions enabling an energy exchange between them. The model comprises a great number of options for capacity expansion. Moreover, the model regards measures for increasing energy efficiency in mapping solar-thermal hot water generation in residential buildings. The energy demand in other sectors is exogenous. The capacity expansion in the TiPS-B-Model takes place in five year steps from 2010 to 2050. The temporal resolution for each step covers 6 seasons, three typical days (weekday, Saturday and Sunday), and 24 hours per day. This results in 432 time slices per year, enabling a detailed analysis of the system operation.


Tomaschek, J., Haasz, T., Fahl, U. (2016): Concentrated solar power generation: Firm and dispatchable capacity for Brazil’s solar future?, AIP Conference Proceedings 1734, 110005.

TIMES-GEECO is an application of the TIMES model generator for South Africa focusing Gauteng region and covering the whole energy system of Gauteng as well as the energy supply structure of South Africa. The model can determine low-priced measures to achieve climate and energy efficiency goals of the region by integrating proposed energy political measures and technologies into a defined technical and socio-economic framework. This integration comprises the transport sector as well as other components of the energy system. All relevant energy carriers on each step of the transformation process are displayed by the model, starting with primary energy supply, covering secondary energy forms such as electricity, up to energy services. Thus, a balance between energy supply and demand can be found.


Tomaschek, J. (2013): Long-term optimization of the transport sector to address greenhouse gas reduction targets under rapid growth: application of an energy system model for Gauteng province, South Africa, Forschungsbericht Band 114, Institut für Energiewirtschaft und Rationelle Energieanwendung (IER), Stuttgart.


This image shows Markus Blesl

Markus Blesl

apl. Prof. Dr.

Assistant professor
Head of Research Department

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