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ANSWER is a user friendly Windows interface with a gentle learning curve specifically developed for working with the MARKAL or TIMES energy system model. The MARKAL and TIMES model generators were developed by the International Energy Agency’s Energy Technology Systems Analysis Programme (IEA-ETSAP). The ANSWER software for working with MARKAL was first available in 1998 and for the newer TIMES model in 2008.

The ANSWER interface provides the energy analyst with facilities for data entry/edit/browse, for initiation of a GAMS TIMES model run, and for results handling. The philosophy of operation of ANSWER is summarized below.
· Model data is stored in a Microsoft Access database.
· Data may be entered into the ANSWER database either manually using the ANSWER interface, or by bulk-loading model data from “smart” Excel spreadsheets.
· RES network diagramming facilitates viewing the underlying energy system structure.
· User-defined technology sets may be used to controlling viewing of subsets of the technology as well as in user constraints.
· MARKAL or TIMES model runs may be seamless submitted to GAMS, results from the run can be brought back into ANSWER, and/or results imported into VEDA-BE. See below for a brief discussion of the VEDA-BE software.
· Model run initiation from ANSWER creates teh text files (in GAMS format) specifying the model instance to be solved by the TIMES GAMS code.
· The TIMES GAMS run produces as output text files containing model results: two sets of results text files can be produced, one for import into ANSWER and the other for import into VEDA-BE. This provides maximum results handling flexibility to the user.
It is recommended that ANSWER users use VEDA-BE powerful and flexible facilities for examining model results (
Product Type
Focus Area
Climate Resilient Development
Low Carbon Development
Scope / Extension
Sub-national, Project, & Local/Community level
Methodological Steps
Spatial / Geographical Coverage Location
All Countries
Related Content
Current Version
ANSWER-TIMES version 6.9.2
System Requirements
Reasonably current generation Intel/Windows computer with min 4Gb RAM, and Excel
File Size (for download)
100Mb for folder with ANSWER executable, sample database, MARKAL/TIMES GAMS source code, and utilities, plus user model databases
Contact Name
New Users - ETSAP Tools Registration Page
Contact Email
e-Learning available
Facilitated Learning Avalable
Case Studies / Manuals
MARKAL/TIMES System Documentation Diverse set of global, regional, national and local applications ANSWER-TIMES Getting Started Manual /ANSWER-TIMES%20Getting%20Started%20Manual-plus-Appendix-Jan2014-final.pdf ANSWER-TIMES User's Guides
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