National Energy Modeling System
The National Energy Modeling System (NEMS) is an economic and energy model of United States energy markets created at the U.S. Department of Energy, Energy Information Administration (EIA). NEMS projects the production, consumption, conversion, import, 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 model contains several modules that interact as part of the equilibrium calculations for long-term forecasting. 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 from year to year by EIA analysts who update the accompanying documentation for version changes annually.
NEMS includes a variety of energy sources used for fuel purposes (heat and power) and feedstock purposes. The primary energy sources of NEMS are Coal, Natural Gas, Distillate Oil (Diesel), Residual Oil, Liquid Petroleum Gases, Coke, Renewables (primarily biomass and wind), Motor Gasoline, Electricity, Petrochemical Feedstocks/Intermediates, Steam, and Asphalt/Road Oil.
Projections from NEMS are given at the nine census division levels, the four census region levels, and the national level.
The primary use for NEMS is to produce the Annual Energy Outlook, published on the EIA website in the early months of each year. 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.