Main Features

ANSWER-TIMES is a user friendly Windows interface with a gentle learning curve specifically developed for working with the TIMES energy system model. The TIMES model was developed by the International Energy Agency’s Energy Technology Systems Analysis Programme (IEA-ETSAP). For information about IEA-ETSAP and the TIMES energy model see and

The ANSWER-TIMES software for working with ETSAP’s newer TIMES model became available in 2008. Since that time, it has been extensively enhanced, and continues to undergo enhancement to improve its in-built knowledge of the TIMES model, and to incorporate support for new TIMES features as they are developed by ETSAP.

The philosophy of operation of ANSWER-TIMES is as follows:

  • The ANSWER-TIMES interface EXE provides the energy analyst with facilities for data entry/edit/browse, for initiation of a GAMS TIMES model run, and for results handling.
  • Model data is stored in a Microsoft Access database.
  • As well as manually entering model data into the ANSWER-TIMES Access database via entry/edit interface facilities, bulk-loading of model data can be carried out using an “Import Model Data from Excel” facility, with “smart” Excel workbooks provided to expedite the preparation of model data.
  • After carrying out a GAMS TIMES model run, results from the run can be brought back into the ANSWER-TIMES database and browsed online, and/or results from the run can be imported into VEDA-BE. See below for a brief discussion of the VEDA-BE software.

Overview of the ANSWER-TIMES system for TIMES modelling, also using VEDA-BE for results handling

Over of ANSWER-TIMES System
  • Data and assumptions are entered into the ANSWER-TIMES database manually using the ANSWER-TIMES EXE, or by bulk-loading model data from “smart” Excel spreadsheets.
  • Model run initiation from ANSWER causes the creation of 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.

    Using VEDA-BE in conjunction with ANSWER-TIMES for Results Processing
    It is recommended that ANSWER-TIMES users acquire the VEDA-BE results processing software because VEDA-BE has powerful and flexible facilities for results aggregation. To acquire VEDA-BE, contact Dr. Amit Kanudia of KanORS Inc ( Use of the VEDA-BE software in conjunction with ANSWER-TIMES is quite straight-forward, since a GAMS TIMES model run initiated by ANSWER-TIMES generates all of the files that need to be imported into VEDA-BE to analyze the results. All that is then required is to manually invoke the VEDA-BE executable to import these files and proceed with results analysis.

TIMES Model Variants (Extensions)

The core TIMES model created by IEA-ETSAP is called “standard TIMES”. Subsequently standard TIMES has been enhanced in various ways, including by the development of a number of TIMES model variants, also referred to as TIMES extensions. It needs to be understood that each model variant (extension) comprises “standard TIMES” plus extra data parameters, variables and equations that are specific to the particular model variant (extension). Some combinations of TIMES model variants (extensions) are permitted.

ANSWER-TIMES supports working with the majority of TIMES model variants and options, including:

  • Standard TIMES
  • Elastic Demand TIMES
  • TIMES with Damages in Objective (LP and NLP variants)
  • TIMES with Discrete Capacity Investment
  • TIMES with Continuous or Discrete Capacity Retirement
  • TIMES with Endogenous Technology Learning (ETL)
  • TIMES-MACRO (MSA and Standard MACRO policy variants)
  • Stochastic TIMES, including with Tradeoff/Sensitivity Analysis
  • TIMES Fix Initial Periods (FIXBOH) option
  • TIMES Time-Stepped Solve option.

When using ANSWER-TIMES’s Run Model facility, specification of the particular TIMES model variant to be used is expedited by the Model Variant and Objective Function Specification form:

Model Variant and Objective Function Specification

For further details regarding TIMES model variants (extensions), see the Additional ANSWER-TIMES Documentation and ETSAP TIMES Documentation sections under Documentation on the ANSWER-TIMES tab.