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National Energy Modeling System (NEMS) Documentation Archive

Coal Market Module - NEMS Documentation

July 10, 2018

Executive Summary

Purpose of the report

This report documents the objectives and the conceptual and methodological approaches used in the development of the National Energy Modeling System's (NEMS) Coal Market Module (CMM) used to develop the Annual Energy Outlook 2018 (AEO2018). This report catalogues and describes the assumptions, methodology, estimation techniques, and source code of the CMM, which for AEO2016 was converted from FORTRAN to the AIMMS [1]. While the overall concepts of the CMM remain unchanged from prior versions, the model framework and organization is now somewhat different under AIMMS.

This document has three purposes. It is a reference document providing a description of the CMM for model analysts and the public. It meets the legal requirement of the U.S. Energy Information Administration (EIA) to provide adequate documentation in support of its statistical and forecast reports (Public Law 93-275, Federal Energy Administration Act of 1974, Section 57(B)(1), as amended by Public Law 94-385). Finally, it facilitates continuity in model development by providing documentation from which energy analysts can undertake model evaluations, model enhancements, data updates, and parameter refinements to improve the quality of the module.

Model summary

The CMM provides annual forecasts of prices, production, and consumption of coal through 2050 [2] for NEMS. The Coal Production Submodule (CPS) generates a set of minemouth coal supply curves by coal supply region, coal type, and mine type. The supply curves are passed to the Domestic Coal Distribution Submodule (DCDS), along with regional coal demand requirements from other NEMS components. The CMM provides delivered coal prices and quantities to the NEMS economic sectors and regions. The DCDS solves for the interregional flows of coal from supply region to demand region, by minimizing the production and transportation costs. The International Coal Distribution Submodule (ICDS) forecasts annual world coal trade flows from major international supply to major demand regions and provides annual forecasts of U.S. coal exports.

Model archival citation

The documentation is archived as part of the NEMS production runs.

Model contact

Information on individual submodules may be obtained from each submodule Model Contact.


1. AIMMS (an acronym for "Advanced Interactive Multidimensional Modeling System") is a software system designed for modeling and solving large-scale optimization and scheduling-type problems. It consists of an algebraic modeling language, an integrated development environment for both editing models and creating a graphical user interface around these models, and a graphical end-user environment.

2. For AEO2016 the time horizon of the model was 2040.

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