The National Energy Modeling System (NEMS) is an economic and energy model of United States energy markets created at the U.S. Energy Information Administration (EIA). NEMS projects the production, consumption, conversion, import, export, and pricing of energy. The model relies on assumptions for economic variables, including world energy market interactions, resource availability (which influences costs), technological choice and characteristics, and demographics.The National Energy Modeling System: An Overview
USDOE-EIA.

Uses

The primary use for NEMS is to produce the '' Annual Energy Outlook'', published on the EIA website in the early months of each year.Annual Energy Outlook Homepage
USDOE-EIA. NEMS is maintained by the EIA Office of Energy Analysis and was first used for ''AEO'' projections in 1994. NEMS is also used for special requests related to scenario analysis, primarily from the U.S. Congress. Subjects such as the economic and environmental impacts of energy-related policy or structure changes are most frequently studied using NEMS.

Design

The model contains several modules that interact as part of the equilibrium calculations for long-term projections. These modules are as follows: * The Integrating Module * The Macroeconomic Activity Module * The Transportation Sector Module * The Residential Sector Module * The Industrial Sector Module * The Commercial Sector Module * The Coal Market Module * The Electricity Market Module * The Liquid Fuels Market Module * The Oil and Gas Supply Module * The Renewable Fuels Module * The International Energy Activity Module * The Natural Gas Transmission and Distribution Module Each of these NEMS modules is maintained annually, with changes to data and methodology described in periodic updates to module-specific documentation reports.National Energy Modeling System model documentation reports
/ref> NEMS accounts for a variety of energy sources used for fuel purposes (heat and power) and feedstock purposes. The primary energy sources and carriers reported in NEMS include crude oil and lease condensate, natural gas plant liquids, dry

natural gas Natural gas (also fossil gas, methane gas, and gas) is a naturally occurring compound of gaseous hydrocarbons, primarily methane (95%), small amounts of higher alkanes, and traces of carbon dioxide and nitrogen, hydrogen sulfide and helium ...

coal Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams. Coal is mostly carbon with variable amounts of other Chemical element, elements, chiefly hydrogen, sulfur, oxygen, and nitrogen. Coal i ...

, nuclear/uranium, conventional hydroelectric power, biomass, other renewable energy, and other (not otherwise specified) primary energy. The end-use consumption energy carriers and feedstocks reported by NEMS include, among others, electricity, natural gas, coal, gasoline, distillate oil ( diesel), residual

oil An oil is any nonpolar chemical substance that is composed primarily of hydrocarbons and is hydrophobic (does not mix with water) and lipophilic (mixes with other oils). Oils are usually flammable and surface active. Most oils are unsaturate ...

, propane, kerosene, liquefied refinery gases, jet fuel, renewables (primarily

biomass Biomass is a term used in several contexts: in the context of ecology it means living organisms, and in the context of bioenergy it means matter from recently living (but now dead) organisms. In the latter context, there are variations in how ...

and wind), and

petrochemical Petrochemicals (sometimes abbreviated as petchems) are the chemical products obtained from petroleum by refining. Some chemical compounds made from petroleum are also obtained from other fossil fuels, such as coal or natural gas, or renewable s ...

feedstocks.AEO Table Browser, Total Energy Supply, Disposition, and Price Summary
/ref> Each of the modules in NEMS may employ its own unique sub-national regional structure. Projections from NEMS are provided at the national level; however, regional results are generally available consistent with the modules' regional definitions. For example, energy consumption by fuel and sector is reported for the nine Census Divisions, the geographic definition used by the four end-use energy demand modules.

Availability

EIA provides access to NEMS to outside users through its model archival program. An archive includes the model source code and input data used to derive a given projection case, such as the "reference case." The stated archive purpose "is to demonstrate that the published results from the AEO reference case can be replicated with the model and to disclose the source code and inputs used." The model is not widely used outside of EIA, as deploying the model requires additional commercial software, such as compilers and optimization modeling packages, in addition to the model source code and data. Information on Obtaining the NEMS Archive

References

{{Energy modeling Energy in the United States Energy models