Jump to main content.


eGRID FAQ

You will need Adobe Reader to view some of the files on this page. See EPA's PDF page to learn more.

What is eGRID?

The Emissions & Generation Resource Integrated Database (eGRID) is a comprehensive inventory of environmental attributes of electric power systems. The preeminent source of air emissions data for the electric power sector, eGRID is based on available plant-specific data for all U.S. electricity generating plants that provide power to the electric grid and report data to the U.S. government. eGRID integrates many different federal data sources on power plants and power companies, including, but not limited to: EPA, the Energy Information Administration (EIA), the North American Electric Reliability Corporation (NERC), and the Federal Energy Regulatory Commission (FERC). Emissions data from EPA are carefully integrated with generation data from EIA to produce useful values like pounds per megawatt-hour (lb/MWh) of emissions, which allows direct comparison of the environmental attributes of electricity generation. eGRID also provides aggregated data by state, U.S. total, company, and by three different sets of electric grid boundaries.

Why eGRID?

Many consumers now have a choice regarding the source of their electricity, and some seek cleaner sources, such as wind and solar power. EPA’s Power Profiler application, which uses eGRID data, helps individual consumers to understand the environmental impacts of their own electricity usage. Power Profiler is updated with the eGRID year 2010 data.

Electricity generation is the dominant industrial source of air emissions in the United States today. Whenever you switch on an electrical appliance, chances are you are contributing to air pollution and greenhouse gas emissions. By documenting the environmental attributes of electric power generation, eGRID can help consumers and researchers to better understand the relationship between electricity and the environment.

In the United States, electricity is generated in many different ways, with a wide variation in environmental impacts. In many states, power companies are required to disclose the environmental attributes of their retail electricity products. eGRID data can be used to support the following activities:

Top of page

What information is contained in eGRID?

For every power plant in the United States, eGRID provides:

eGRID also provides separate data files at the boiler and generator level.

Emissions and resource mix data from the plant level are aggregated by electric generating company, parent company (company level data is not provided for year 2009 or 2010data), state, U.S. total, and three types of power grid regions:

All editions of eGRID currently contain data for years 2010, 2009, 2007, 2005, and 2004, 2000, 1999, 1998, 1997, and 1996.

The 9th edition of eGRID contains year 2010 power interchange data and grid gross loss factors for the three continental interconnections and Alaska, and Hawaii. Interconnection interchange and gross loss factors are also presented for year 2009 data. Net imports-exports by state are provided for years 2007, 2005 and 2004. Data on net imports-exports by state and power interchange between grid regions are included in eGRID data for years 1996 through 2000.

Top of page

Who uses eGRID?

eGRID is valuable to those in the Federal Government, state and local governments, non-governmental organizations, and academia. It is also useful to companies seeking environmental information about the electric power sector in the United States. eGRID is most often used to estimate indirect emissions from electricity purchases, in GHG inventories, for carbon footprinting, and for estimating avoided emissions from programs and projects that reduce consumption of grid-supplied electricity. eGRID data is cited by emission inventory and registry protocols, by various emission calculation tools and applications, by many academic papers, by many consultants, and is used for many research applications and efforts.

Within EPA, eGRID data are used by the following applications and programs: Power Profiler, Center for Corporate Climate Leadership, Portfolio Manager, WasteWise Office Carbon Footprint Tool, the Green Power Equivalency Calculator, the Household Greenhouse Gas Emissions Calculator, and the Greenhouse Gas Equivalencies Calculator.

When EPA announced the winners of its 2011 Apps for the Environment challenge, two winning apps — Light Bulb Finder Exit EPA Disclaimer and Joulebug Exit EPA Disclaimer used eGRID data.

In 2010, Executive Order 13514 was issued, requiring Federal agencies to “measure, report, and reduce their greenhouse gas emissions from direct and indirect activities.” The Federal GHG Accounting and Reporting Guidance that accompanied this order recommended using eGRID non-baseload emission rates to estimate the Scope 2 emission reductions from renewable energy.

Fueleconomy.gov, a partnership between EPA and DOE, uses eGRID data to estimate the total GHG emissions from electric and plug-in hybrid vehicles in its Greenhouse Gas Emissions for Electric and Plug-in Hybrid Electric Vehicles calculator.

eGRID is also used by other Federal Government agencies such as Oak Ridge National Laboratory (ORNL) for their Combined Heat and Power Calculator, the National Energy Technology Laboratory (NETL) for their sponsored Distributed National Carbon Sequestration Database and Geographic Information System (NATCARB), and the National Renewable Energy Laboratory (NREL) for their micropower distributed generation optimization model named HOMER.

One of the most popular recent uses of eGRID is to determine the indirect GHG emissions from electricity purchases and avoided GHG emissions from projects and programs that reduce the demand for grid supplied electricity. For example, The Climate Registry, the California Climate Action Registry, and the Greenhouse Gas Protocol Initiative cite eGRID for use in estimating Scope 2 GHG emissions from electricity purchases in the United States. Most carbon footprint calculators that are applicable to the United States use eGRID data.

States and local governments rely on eGRID data for electricity labeling (environmental disclosure programs), emissions inventories, and registries as well as for efforts to analyze air emissions from the electric power sector. Several states have used eGRID to publish state specific emissions information or have used eGRID to inform policy decisions.

RECS Tracking Systems, such as ISO-New England’s Generation Information System (GIS) and PJM Interconnection’s Generation Attribute Tracking System (GATS), use eGRID data.

eGRID is used by many nongovernmental organizations in their tools and analysis. One example is Carbon Footprint Visualizations Exit EPA Disclaimer by Carbon Visuals, which illustrates accurate volumetric images to visualize the carbon footprint of all U.S. power stations.  Another example is The University of California, Berkeley’s CoolClimate Carbon Footprint Maps Exit EPA Disclaimer.

Top of page

What is new in eGRID?

The 9 th edition of eGRID is updated with year 2010 data and a few minor improvements:

Please see the Technical Support Document (PDF) (112 pp., 1.2M) for more details.

Because there are some methodological changes in different editions of eGRID from year to year, please use caution when comparing data from different years.

Top of page

What do the eGRID subregion and NERC region maps look like?

eGRID Subregion Representational Map.
Map of eGRID Subregions

This is a representational map; many of the boundaries shown on this map are approximate because they are based on companies, not on strict geographical boundaries.

NERC Region Representational Map.
Map of eGRID Subregions

This is a representational map; many of the boundaries shown on this map are approximate because they are based on companies, not on strict geographical boundaries.

Top of page

Can I receive a shape file for the eGRID subregion or NERC region maps?

EPA cannot release a shape file for the eGRID subregions or the NERC regions because these maps are representational. Many of the boundaries shown on these maps are approximate and are not based on strict geographical boundaries. The NERC regions and eGRID subregions are based on groups of power control areas (a.k.a. balancing authorities). Some boundaries shown on the maps are approximations of overlapping power control areas. Also, plants assigned to a particular eGRID subregion may not be connected by transmission lines to a particular power control area and may also be located far away from the utility service territories that the power control area serves. For example, the Intermountain Power Project plant’s power control area is the Los Angeles Department of Water and Power, yet, this plant is located in Utah.

Top of page

What are the regional emission rates and resource mix?

Summary information for data years 2010, 2009, 2007, 2005 and 2004 by state, eGRID subregion, NERC region, and the U.S. can be found in the following documents:

Top of page

How can I find out when eGRID is updated?

If you are interested in receiving an email alert once updated versions of eGRID are issued, please enter your email address and comment like "Please inform me when an updated eGRID is available" in the feedback field of the eGRID feedback form.

Top of page

What other emissions data are available from EPA?

Other EPA emissions data sources provide data on emissions associated with electricity generation. Air Trends Reports are EPA's "report card" on the status of air quality and air pollutant emissions. Reports are published annually, about ten months after year-end. U.S. Greenhouse Gas Inventory Reports include inventories of U.S. greenhouse gas emissions and sinks. In addition, Clean Air Markets Division Progress Reports includes emissions data for power plants in the Acid Rain Program or the NOX Budget Trading Program. Also, see the National Emissions Inventories for the U.S.

Top of page

Who can I contact for more information?

For questions about eGRID, please use the feedback form.

Top of page

EPA welcomes comments on eGRID. Please enter any comments about the content or function of eGRID.







Local Navigation


Jump to main content.