U.S. Energy Information Administration - EIA - Independent Statistics and Analysis
Annual Energy Outlook 2014
Availability of the National Energy Modeling System (NEMS) Archive
NEMS has been developed primarily for use by the modelers at Energy Information Administration (EIA) who understand its structure and programming. As a result, NEMS is only used by a few organizations outside of the EIA. Most people who have requested NEMS in the past have found out that it was too difficult or rigid to use. For example, it is not typically used for state-level analysis and is poorly suited for application to other countries. However, many obtain the model simply to use the data in its input files or to examine the source code. EIA is the developer of NEMS, so most of what constitutes NEMS is in the public domain (and no licenses are required), but NEMS does contain some proprietary components that are outside the public domain which can be licensed as discussed below.
NEMS is an integrated model of the U.S. energy system linked to a macroeconomic model. For an overview of NEMS, see NEMS: An Overview. More detailed documentation of NEMS is available at http://www.eia.gov/reports/index.cfm?t=Model Documentation.
An archive of NEMS as used for the reference case for the Annual Energy Outlook 2014 (AEO) Early Release is available, on an as-is basis, on our web site. This archive is an encrypted zip file (found in http://www.eia.gov/archive/aeozipfiles/aeo/ref2014.no.zip). The purpose of the archive is to demonstrate that the published results from the AEO reference case can be replicated with the model, some of which is proprietary, and to disclose the source code and inputs used.Â It does not include an executable of the model, which can be generated from the source code of the model with the appropriate software.
Note that the version of NEMS downloaded depends on whether the proprietary Global Insight model and the proprietary McGraw-Hill Construction commercial floorspace data are purchased. Download aeo2014.no.zip (at the link found at the bottom of this document) if you do not plan to purchase the commercial floorspace data; download aeo2014.yes.zip (at the link found at the bottom of this document) if you plan to purchase the commercial floorspace data either with or without the Global Insight model. These files are encrypted. Please contact Paul Kondis (contact information at the bottom of this document) for the key to the file you download.
The NEMS archive is designed for use with Microsoft Windows Server 2008 and requires these software packages that are not provided by EIA and must be obtained by the user from the vendors:
1) Intel Visual Fortran, Standard Edition, version 11.1 (version 12 is latest but 11.1 may still be available and should be installed for compatibility). (Version 11.1 can be installed on 64-bit computers, but EIA installed it as 32-bit on a 64-bit computer.)
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The Electricity Market Module and the Coal Market Module of NEMS use OML.
3) The Xpress optimizer from the Fair-Isaac Corporation, version 2008a, is used at EIA to solve the Electricity Capacity Planning submodule and the Liquid Fuels Market Module. The OML optimizer can be used in place of Xpress for the Electricity Capacity Planning submodule, but the results will differ from EIA's results and the execution time will increase. EIA has made arrangements with Fair-Isaac Corporation to provide a single license of the Xpress solver to a limited number of organizations who want to use it for NEMS. Contact EIA to request a single license for Xpress under this arrangement.
4) The General Algebraic Modeling System (GAMS) is used for the Carbon Transport and Storage routine (currently called from within the Electricity Capacity Planning submodule) and for the Liquid Fuels Market Module. EIA used GAMS version 24.1.1 for the AEO 2014. This implementation uses the Xpress solver mentioned above. The price schedule for GAMS can be found at http://gams.com/sales/commercialp.htm. EIA purchased the development license (rather than the run-time license), which allows changes to the linear program matrix during execution of a NEMS run.
5) (Optional) For macroeconomic feedback cases only, the Global Insight Macro Model
(http://www.globalinsight.com/ ) as implemented with the EViews7 software package from QMS ( http://www.eviews.com/
is used. EIA is currently using EViews7 standard edition, version 7.2, July 6, 2012 build. The Global Insight macro module is called directly from NEMS if the "macro feedback switch" in NEMS is turned on. Users can elect to run NEMS without macro feedback, in which case the run uses a static input file with the macroeconomic inputs taken "as is". When the Macro feedback switch is on, NEMS will attempt to call the macro model by executing EVIEWS7 using the Global Insight model's "work files" as the input to Eviews7. These Eviews7 work files are not included in the archive, but can be obtained from EIA after licensing the Global Insight model. A copy of Eviews7 must also be acquired to run the Global Insight model. The Global Insight representative is Jamie Niedbalski, (Jamie.Niedbalski@ihsglobalinsight.com).
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NEMS is computationally intensive and requires a memory address space of about 1.5 gigabytes. EIA is now running NEMS on 64-bit Windows PCs with the 64-bit Windows Server 2008. The EIA servers running NEMS have 32 gigabytes of RAM to accommodate multiple runs simultaneously.
Runs of NEMS take about 1-2 hours on the EIA terminal servers purchased in 2010, but most scenarios are solved by making a series of complete runs, known as cycles, that are used to resolve convergence and foresight issues. Such multi-run scenarios may take about 6-12 hours to run. Runs of some individual parts of NEMS, if run separately, such as the energy demand models, can take only a few minutes. Output of a single run is about 15 gigabytes, but is compressed to about 10 gigabytes once the run finishes.
Brief instructions for compiling the code, setting up a run, and replicating the AEO reference case are included in a "readme.txt" file included with the archive. EIA does not have a budget to support the outside use of NEMS.
Technical questions about the NEMS archive and requests for the zip file encryption key can be directed to Paul Kondis, at 202-586-1469, (firstname.lastname@example.org).
Links to the model:
without commercial floorspace: http://www.eia.gov/archive/aeozipfiles/aeo/ref2014.no.zip
with commercial floorspace: http://www.eia.gov/archive/aeozipfiles/aeo/ref2014.yes.zip