The MESSAGEix framework

The ix modeling platform (source: [1])

Overview and scope

MESSAGEix is a versatile, open-source, dynamic systems-optimization modelling framework. It was developed for strategic energy planning and integrated assessment of energy-engineering-economy-environment systems (E4). The framework can be applied to analyse scenarios of the energy system transformation under technical-engineering constraints and political-societal considerations. The optimization model can be linked to the general-economy MACRO model to incorporate feedback between prices and demand levels for energy and commodities. The equations are implemented in the mathematical programming system GAMS for numerical solution of a model instance.

The MESSAGEix framework is fully integrated with IIASA’s ix modeling platform (ixmp), a data warehouse for high-powered numerical scenario analysis. The platform supports an efficient workflow between original input data sources, the implementation of the mathematical model formulation, and the analysis of numerical results. The platform can be accessed via a web-based user interface and application programming interfaces (API) to the scientific programming languages Python and R. The platform also includes a generic data exchange API to GAMS for numerical computation.

This documentation provides an introduction and the mathematical formulation of the MESSAGEix equations and auxiliary functions. For the scientific reference of the framework, see Huppmann et al. (2019) [1]. The formulation of MESSAGEix is a re-implementation and extension of ‘MESSAGE V’ (Messner and Strubegger, 1995 [5]), the Integrated Assessment model developed at the International Institute for Applied Systems Analysis (IIASA) since the 1980s. For an overview of the MESSAGEix model used at the IIASA Energy Program and a list of recent publications, please refer to the MESSAGE-GLOBIOM documentation website.

Getting Started

• MESSAGEix framework overview

• Installation

• Tutorials

Have a question? First, check the Frequently asked questions, then try the community Google group:

• on the Web at https://groups.google.com/d/forum/message_ix, or

• via e-mail at <message_ix@googlegroups.com>.

Developing MESSAGEix models

Developing a valid, scientific MESSAGEix model requires careful use of the framework features. This section provides guidelines for how to make some common model design choices.

• Efficiency - output- vs. input defined technologies

• Add model years to an existing Scenario

• Postprocessing and reporting

• Debugging and data validation

• Tune MESSAGE-MACRO

Mathematical Specification

These pages provide comprehensive description of the variables and equations in the core MESSAGEix mathematical implementation.

• Sets and mappings definition

• Parameter definition

• MESSAGE core formulation

• Solve statement workflow

• Standard output reports

• Auxiliary investment parameters

• MACRO core formulation

Using and contributing to MESSAGEix

MESSAGEix and the ix modeling platform are licensed under the APACHE 2.0 open-source license.

Anyone is encouraged to use the framework to develop energy system and integrated assessment models! Please see the User guidelines and notice for using the framework in scientific research. Contributions to the framework itself, which enable new features across all models, are also welcome.

• Python & R API

• What’s New

• User guidelines and notice

• Contributing to MESSAGEix development

• Frequently asked questions

• References