Frequently asked questions

What’s included in a ‘typical’ MESSAGEix model?

A typical MESSAGEix model is based on a suite of technologies such as power plants, which represent a reference energy system (RES). Each technology is characterised by its input and output commodities, costs (investment, fixed and variable components), and other technical/engineering parameters. The model minimizes the total system cost while meeting a given demand for energy services or commodities.

Which policies and regulatory measures can be included?

The MESSAGEix framework can represent a wide range of mitigation options and policies to analyse transformation pathways. For example, bounds or taxes on emissions can be defined to shift the system towards a low-emission technology mix. Upper or lower bounds on deployment of new technologies can also be easily included.

Under which license is MESSAGEix released?

MESSAGEix and the ix modeling platform (ixmp) are released under the APACHE 2.0 open-source license. You are free to use, modify and redistribute the source code of the framework as long as you clearly indicate any changes. You must also include the NOTICE file in any redistributed work.

Can I use MESSAGEix for my own analysis?

Yes! We invite you to develop your own energy system or integrated assessment model based on the MESSAGEix framework. Please read the NOTICE for user guidelines on naming conventions of new models based on MESSAGEix.

How can I contribute to the development of the MESSAGEix framework?

We use GitHub for code development and management of issues and bug reports. In addition, we use a Google-group ( as a discussion forum and community mailing list.

I have more questions…

Please have a look at the discussion forum at the MESSAGEix Google group - maybe your issue has been discussed there already! If not, just send an email to the community mailing list.