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Annual Energy Outlook 2015

Release Date: April 14, 2015   |  Next Release Date: March 2016 |  correction  |  full report

Availability of the National Energy Modeling System (NEMS) Archive

NEMS has been developed primarily for use by the modelers at the 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 but 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 2015 (AEO) 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/ref2015.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. It does not include an executable of the model, but one 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 McGraw-Hill Construction commercial floorspace data are purchased. Download aeo2015.no.zip (at the link found at the bottom of this document) if you do not plan to purchase the commercial floorspace data; download aeo2015.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. Files for the proprietary IHS Global Insight macroeconomic model will be sent separately once arrangements for licensing the model are made with IHS Global Insight.

The NEMS archive is designed for use with Microsoft Windows Server 2012 (similar to Windows 8 on PCs) 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, 64-bit version. (Version 15, packaged as "Intel® Parallel Studio XE 2015 Composer Edition for Fortran Windows" is the latest but version 11.1 may still be available and should be installed for compatibility. Once you purchase Intel Fortran, you can select to download earlier versions by going to their support site and logging in.). (http://software.intel.com/en-us/intel-visual-fortran-compiler-for-windows)

2) The Electricity Market Module and the Coal Market Module of NEMS use the Optimization and Modeling Library (OML) License from Ketron Optimization, LLC ( http://www.ketronms.com/oml.shtml ) with optional XpressMP barrier interface. The OML libraries are in the archive file. The license key to make them operational must be obtained independently from:

Ketron Optimization Support Services, LLCP.O. Box 71-1601
Oak Hill, VA 20171-1601 USA
Phone: 703-736-4805 (Fax: 4805)

Once the Ketron OML license files are obtained, you will need to copy all the files to the MPSIII license folder. Typically for the normal OML install, the license folder would be at C:\MPSIII. Make sure there is an Environmental Variables path set up for MPSIII.CFG. To set this Environmental Variable, right-click "My Computer", select Properties, select "Advanced System Settings", and select the "Environmental Variables" button under the "Advanced" tab. If there is no "MPS" variable defined under "System Variables", select "New..." and add the Variable name "MPS" and define the value as "C:\MPSIII\".

3) The Xpress optimizer from the Fair-Isaac Corporation, version 2008a, is used at EIA to solve the Electricity Capacity Planning submodule of the Electricity Marketing Model, the Liquid Fuels Market Module, and the Carbon Transport, Utilization, and Storage routine (currently called from within the Electricity Capacity Planning submodule). 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 through June, 2015. To obtain the Xpress Optimization license file, you will need to do the following:

  1. Contact EIA to request a single license for Xpress under EIA's arrangement with Fair-Isaac.
  2. Download and install Xpress from the FICO web site ( http://www.fico.com/en/Pages/default.aspx ). Run the xphostid executable. Copy the results and send to EIA (paul.kondis@eia.gov).
  3. Notify FICO that you are obtaining the Xpress Optimization license (itservices@fico.com) to run EIA’s NEMS model and request an on-line account.
  4. EIA will forward the result from the xphostid tool to FICO, who will then send a license file.

4) The General Algebraic Modeling System (GAMS) is used for the Carbon Transport, Utilization, and Storage routine and for the Liquid Fuels Market Module. EIA used GAMS version 24.3.1 for the AEO 2015. This implementation uses the Xpress solver mentioned above. Links to the commercial and academic price schedules for GAMS can be found at http://gams.com/sales/sales.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 IHS Global Insight Macro Model (http://www.globalinsight.com/ ) as implemented with the EViews8 software package from QMS ( http://www.eviews.com/ ) is used. EIA is currently using EViews8 standard edition, version 8.1, October 21, 2014 build. The IHS 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 EViews8 using the Global Insight model's "work files" as the input to Eviews8. These Eviews8 work files are not included in the archive, but can be obtained from EIA after licensing the IHS Global Insight model. A copy of Eviews8 must also be acquired to run the IHS Global Insight model. The IHS Global Insight representative is Jamie Niedbalski, (Jamie.Niedbalski@ihs.com).

6) (Optional) Commercial floorspace data from McGraw-Hill Construction, which EIA inserts into one of the EViews8 input work files for the macroeconomic module. This proprietary data is used to develop long term floorspace growth projections and is used by the commercial module in connection with commercial floorspace stock vintaging calculations. Those of you who purchased the commercial floorspace data in 2011 have the version that EIA used in the AEO2015 runs. (Note that the file you download via the links at the bottom of this document is dependent on your licensing plans. Download aeo2015.yes.zip if you plan to purchase the commercial floorspace data either with or without the IHS Global Insight model; download aeo2015.no.zip if you do not plan to purchase the commercial floorspace data. If you do not purchase the commercial floorspace data, the NEMS code you receive will be set up to run without it, regardless of whether you purchase the IHS Global Insight model itself.). A license that allows EIA to provide the commercial floorspace data can be obtained from McGraw-Hill Construction for $3000 by contacting Carolyn Aliaga (202-383-3709; Carolyn_Aliaga@mhfi.com). Her mailing address is:

Carolyn Aliaga
McGraw-Hill Construction
1200 G Street NW
Washington, DC 20005

NEMS is computationally intensive and requires a memory address space of about 1.5 gigabytes (GB) with some additional memory, about 1 GB, allocated dynamically. NEMS runs as a 64-bit application. EIA is now running NEMS on 64-bit Windows PCs with the 64-bit Windows Server 2012. The EIA servers running NEMS have 128 GB of RAM to accommodate multiple runs and users simultaneously, but a single copy of NEMS may execute on a single-user system with 4GB of RAM. NEMS also can be run on a desktop/laptop using Windows 7 with sufficient RAM and processing speed. EIA runs the integrated NEMS run in two parts simultaneously (in parallel) to speed run time, so two processor cores per integrated run are used. If a non-integrated run is done (e.g., electricity + renewables) then likely only one processor core per run is needed. With a quad core processor, one can run two integrated parallel runs or four non-integrated runs with little speed loss. To run four non-integrated runs in parallel, at least 8 GB of RAM is suggested (16 GB would be better).

Runs of NEMS take about 1-2 hours on the EIA servers purchased in 2014 (with dual Intel XEON "E5-2690 v2" processors, 3.6 Ghz), 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 17 gigabytes, but is compressed to about 7 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, (paul.kondis@eia.gov).

Links to the model:
without commercial floorspace: http://www.eia.gov/archive/aeozipfiles/aeo/ref2015.no.zip
with commercial floorspace: http://www.eia.gov/archive/aeozipfiles/aeo/ref2015.yes.zip