Documentation of the National Energy Modeling System (NEMS) modules

A brief introduction of the National Energy Modeling System (NEMS) is available on the Assumptions page. A more detailed overview is provided below in the report: The National Energy Modeling System: An Overview.

NEMS is a modular system. The modules represent each of the fuel supply markets, conversion sectors, and end-use consumption sectors of the energy system. The modular design also allows us to use the methodology and level of detail most appropriate for each energy sector. NEMS executes each of the component modules to solve for the prices of energy delivered to end users and the quantities consumed by product, region, and sector. The information flows also include economic activity, domestic production, and international petroleum supply. NEMS calls each supply, conversion, and end-use demand module in sequence until the modeling system reaches an equilibrium between supply and demand.