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eGRID FAQ
eGRID
Quick Links
- eGRID2007 Version 1.1 - all files (ZIP) (18 MB)
- eGRID2007 eGRID subregion GHG output emission rates for year 2005 (PDF) (1 pp., 193 K, About PDF)
- eGRID2007 year 2005 Summary Tables (PDF) (12 pp., 511 K)
- eGRID2007 Technical Support Document for year 2005 data (PDF) (100 pp., 0.99MB)
- eGRIDweb application
- eGRIDweb Users Manual (PDF) (48 pp., 1.9M)
- What is eGRID?
- Why eGRID?
- What information is contained in eGRID?
- Who uses eGRID?
- What is new in eGRID?
- What do the eGRID subregion and NERC region maps look like?
- What are the regional emission rates and resource mix?
- How can I find out when eGRID is updated?
- What other emissions data are available from EPA?
- Who Can I Contact For More Information?
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, from three different federal agencies: EPA, the Energy Information Administration (EIA), 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?
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 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. Many consumers now have a choice regarding the source of their electricity, and some seek cleaner sources, such as wind and solar power. Data from eGRID underlies EPA's Power Profiler application, which enables individual consumers to identify the environmental impacts of their own electricity usage. Power Profiler is updated with the eGRID2007 year 2005 data.
For policymakers, eGRID data can be used to support the following activities:
- Greenhouse gas registries and inventories,
- Consumer information disclosure,
- Renewable portfolio standards,
- Development of emissions inventories and emission standards,
- Analysis of changing power markets, and
- Estimation of avoided emissions.
What information is contained in eGRID?
For every power plant and electric generating company in the United States, eGRID provides:
- A detailed emissions profile, covering nitrogen oxides (NOX), sulfur dioxide (SO2), carbon dioxide (CO2), mercury (Hg), and new this year, methane (CH4) and nitrous oxide (N2O). Emissions are reported in tons (pounds for Hg, CH4 and N2O), output emission rates in lb/MWh (pounds per gigawatt-hour for Hg, CH4 and N2O), and input-based emission rates in pounds per million British thermal units (lb/MMBtu) (pounds per billion Btu for Hg, CH4 and N2O),
- Generation resource mix, in megawatt-hours and percent, and
- Identification, ownership, corporate affiliation, and locational information.
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, state, U.S. total, and three types of power grid regions:
- NERC region, as designated by the North American Electric Reliability Council; plus Alaska and Hawaii,
- eGRID subregion (subregions of NERC regions), and
- Power control area (smaller regions of the power grid in which all power plants are centrally dispatched).
eGRID2007 data encompass nearly 2,000 generating companies and nearly 5,000 power plants. eGRID currently contains data for years 2005 and 2004 in eGRID2007 and data for years 1996 through 2000 in the archived eGRID2002.
In order to keep up with the rapidly changing U.S. power industry, eGRID data reflect the industry structure, including company mergers, power plant divestiture to nonutility companies, and grid reconfigurations that exist close to the time of publication. For example, 1999 and 2000 data reflect the industry structure through December 31, 2002; 2004 data reflect the industry structure through October 1, 2006; and 2005 data reflect the industry structure through December 31, 2007.
eGRID2007 contains year 2005 and 2004 data on net imports-exports by state. The previous edition, eGRID2002, includes data on net imports-exports by state and power interchange between grid regions for years 1996 through 2000.
Who uses eGRID?
EPA uses eGRID as a key data source for tools and programs such as Power Profiler, Climate Leaders, Portfolio Manager, the Green Power Equivalency Calculator, the Personal Greenhouse Gas Emissions Calculator, and the Greenhouse Gas Equivalencies 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.
States rely on eGRID data for electricity labeling (environmental disclosure programs), emissions inventories, and registries (such as the California Climate Action Registry, The Climate Registry), and for policy decisions/impacts such as output based standards; many states also publish state specific eGRID data on the web.
RECS Tracking Systems, such as ISO-New England’s Generation Information System (GIS) and PJM Interconnection’s Generation Attribute Tracking System (GATS) utilize eGRID data.
eGRID is used by nongovernmental organizations’ (NGOs) tools and analysis, including, but not limited to:
- Northeast States for Coordinated Air Use Management (NESCAUM) analysis,
- Ozone Transport Commission’s (OTC) Emission Workbook, the Greenhouse Gas (GHG) Protocol Initiative,
- Rocky Mountain Institute’s Community Energy Finder,
- Leonardo Academy’s “Cleaner and Greener Environmental Program,”
- National Resource Defense Council’s Benchmarking Air Emissions, and
- Emission Solution’s Carbon Footprint Calculator.
eGRID has many academic uses and is often cited in research and analysis papers and lessons prepared by consulting groups and universities.
What is new in eGRID?
(January 28, 2009) eGRID2007 is updated to Version 1.1 from Version 1.0, which was released on October 16, 2008. This update revises CO2 emissions and emission rates for 213 plants in the 4,998 plant database and makes a minor adjustment of alphabetical order in the boiler, generator, and plant files. The CO2 emissions and emission rates are corrected for aggregated data. A new release notes file, which provides a brief explanation of the changes, is added to Version 1.1.
(October 16, 2008) eGRID2007 contains several new fields of information and several methodological improvements. Please see the Technical Support Document (PDF) (100 pp., 0.99MB, About PDF) for more details.
The following are new data elements in the current edition:
- Emissions and emission rates for two additional Greenhouse Gases (GHGs), namely methane (CH4) and nitrous oxide (N2O), are included beginning at the plant level.
- Four new resource mix variables, combustion and noncombustion generation in terms of MWh and percent, are included beginning at the plant level.
- Seven new combustion output emission rates — for ozone season NOx and annual NOx, SO2, CO2, CH4, N2O, and Hg — are included beginning at the plant level.
- New plant level flags indicate whether the plant burns any amount of coal, whether the plant combusts fuel, and whether the latitude and longitude values are based on the county centroid.
The following are methodological changes new to this edition of eGRID:
- A revised methodology for splitting out the municipal solid waste data into biomass and fossil components;
- Updated latitude and longitudes and data sources;
- Updated methodology for missing net generation data;
- Updated primary fuel determination; and
- Emissions from geothermal plants are now included.
State import-export files for 2004 and 2005, and the U.S. Generation and Consumption file are included in this edition of eGRID.
eGRIDweb, which will make viewing eGRID data easier, will be launched in spring 2009.
Because there are some methodological changes in different editions of eGRID from year to year, please use caution when comparing data from different years.
What do the eGRID subregion and NERC region maps look like?
eGRID Subregion Representational Map
NERC Region Representational Map
What are the regional emission rates and resource mix?
Summary information for data years 2005 and 2004 by state, eGRID subregion, NERC region, and the U.S. can be found in the following document:
- eGRID2007 year 2005 Summary Tables (PDF) (12 pp., 511 K, About PDF)
- eGRID2006 year 2004 Summary Tables (PDF) (9 pp., 3M, About PDF)
How can I find out when eGRID is updated?
If you are interested in receiving an 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.
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.
Who Can I Contact For More Information?
For questions about eGRID, contact Art Diem at 202-343-9340, or provide us your feedback on eGRID.