Cambium data sets contain modeled hourly emission, cost, and operational data for a range of possible futures of the U.S. electricity sector through 2050, with metrics designed to be useful for forward-looking analysis and decision support. 

Cambium is annually updated and expands on the metrics reported in NREL’s Standard Scenarios—another annually released set of projections of how the U.S. electric sector could evolve across a suite of potential futures. 

In its fourth annual edition, the 2023 Cambium data sets have been updated to reflect changes in technology, market, and policy as well as improvements to the underlying models.

The 2023 Cambium release includes three products:

  • The full 2023 Cambium data sets available for viewing and downloading through NREL’s Scenario Viewer
  • A workbook meant to facilitate the use of Cambium’s long-run marginal emission rate metrics
  • An NREL report describing the scenarios, defining metrics and methods, describing major changes since the last release, and discussing intended uses and limitations of the data set.

Long-Run Marginal Emission Rates

The long-run marginal emission rate is an estimate of the rate of emissions that would be either induced or avoided by a change in electric demand, taking into account how the change could influence both the operation as well as the structure of the grid (i.e., the building and retiring of capital assets, such as generators and transmission lines). It is therefore distinct from the more-commonly-known short-run marginal, which treat grid assets as fixed.

Cambium data sets contain long-run marginal emission rate estimates for the contiguous United States.
Download the workbooks containing this metric and guidance on its use.

Screenshot of the Cambium data sets depicting an example long-run marginal CO2 emission rate pattern (kg/MWh) for the Contiguous United States, from the mid-case of the 2020 Standard Scenarios data set. The data is arranged into a heatmap format depicting number of hours in a day and the months in a year.
An example long-run marginal CO2 emission rate pattern (kg/MWh) for the contiguous United States from the mid-case scenario of the 2020 Standard Scenarios data set.

Access the Full Data Sets

Beyond long-run marginal emission rates, Cambium databases include other emission, cost, and operational metrics. The full data sets can be viewed and downloaded via the Cambium projects within NREL’s Scenario Viewer.

Screenshot of the interface of the Cambium Viewer, which includes four sections of interactive data in map and chart formats.

The Cambium data sets are a companion product to NREL’s Standard Scenarios, which contains a broader suite of scenarios with fewer metrics and only at annual temporal resolution. Both products project the possible evolution of the U.S. electricity sector using NREL’s publicly available Regional Energy Deployment System (ReEDS) long-term capacity expansion model. 


Cambium 2023 Scenario Descriptions and Documentation, NREL Technical Report (2024)

Long-Run Marginal Emission Rates for Electricity—Workbooks for 2023 Cambium Data, NREL Data Workbook (2024)

Planning for the Evolution of the Electric Grid With a Long-run Marginal Emission Rate, iScience (2022)

2022 Standard Scenarios Report: A U.S. Electricity Sector Outlook, NREL Technical Report (2022)

Integrating Cambium Marginal Costs Into Electric-Sector Decisions, LBNL Technical Report (2021)


Pieter Gagnon

Senior Energy Systems Researcher