physics

National Energy Modeling System

National Energy Modeling System is a physics topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand National Energy Modeling System rather than just read about it. In short: 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).

Key takeaways

National Energy Modeling System belongs to physics; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect National Energy Modeling System to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of National Energy Modeling System from memory before moving on to harder problems.

Reference excerpt

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.

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. 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. 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, coal, 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, propane, kerosene, liquefied refinery gases, jet fuel, renewables (primarily biomass and wind), and petrochemical feedstocks. 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.

References

Worked examples

Example 1 — a first encounter with National Energy Modeling System

Start with the simplest possible case. Write down what National Energy Modeling System claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In physics, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to National Energy Modeling System before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about National Energy Modeling System ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of National Energy Modeling System

In research: National Energy Modeling System appears in physics research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses National Energy Modeling System in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: National Energy Modeling System is common in secondary-school and first-year university syllabi. It links to neighbouring topics Energy in the United States, Energy models, so understanding it makes those chapters shorter.
In everyday life: Look for National Energy Modeling System outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study National Energy Modeling System in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what National Energy Modeling System means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain National Energy Modeling System out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is National Energy Modeling System in simple terms?

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).

Why does National Energy Modeling System matter?

Because it connects several physics ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study National Energy Modeling System?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on National Energy Modeling System.