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NEMS - National Energy Modeling System: An Overview

October 1, 2009


The National Energy Modeling System (NEMS) is a com puter-based, energy-economy modeling system of U.S. through 2030. NEMS projects the production, imports, conversion, consumption, and prices of energy, sub ect to assumptions on macroeconomic and financial factors, world energy markets, resource availability and costs, behavioral and technological choice criteria, cost and per formance characteristics of energy technologies, and de mographics. NEMS was designed and implemented by the Energy Information Administration (EIA) of the U.S. Department of Energy (DOE).

The National Energy Modeling System: An Overview 2009 provides an over view of the struc ture and meth odology of NEMS and each of its components. This chapter provides a description of the design and objectives of the system, followed by a chapter on the overall model ing structure and solution algorithm. The remainder of the report summa rizes the methodology and scope of the component modules of NEMS. The modelde scrip tions are in tended for readers familiar with terminology from economic, operations research, and energy model ing. More detailed model documentation re ports for all the NEMS modules are also avail able from EIA (Appendix, "Bibliography").

Purpose of NEMS

NEMS is used by EIA to project the energy, economic, environmental, and security impacts on the United States of alternative energy policies and different as sump tions about energy markets. The projection horizon is approximately 25 years into the future. The projections in Annual Energy Outlook 2009 (AEO2009) are from the present through 2030. This time period is one in which technology, demograp ics, and economic conditions are sufficiently understood in order to represent energy mar kets with a reasonable degree of confidence. NEMS provides a consistent framework for representing the complex interactions of the U.S. energy system and its response to a wide variety of alternative assumptions and policies or policy initiatives. As an annual model, NEMS can also be used to examine the impact of new energy programs and policies.

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