
The electric power industry in the United States is composed mainly of"traditional" electric utilities, legal entities that, along with distributionfacilities, have the core purpose of delivering electricity to the public.Electric utilities can be investor-owned, municipal, state or federalutilities, as well as rural electricity cooperatives. The US electricity sectoralso comprises non-traditional participants, such as energy service providers,power marketers, independent power producers, and combined heat and powerplants.
The earth's climate has suffered through many changes over time, with events ranging from ice ages to warm, interglacial periods (such as the present era) documented.
Emissions and Generation Resource Integrated Database
The United States air pollution data for CO2, NOx, SO2, CH4, N2O and Hg were obtained from the United States EPA emissions and Generation Resource Integrated Database (eGRID2007). The eGRID2007 is a broad inventory of environmental features for all the electricity generating plants that provide power to the electric grid and report data to the United States government.
For the present report, data for a total of 2,834 power plants in the United States were analyzed; however, as explained earlier and, as shown in Table 2.4 below (“total (non-negative)”), only data for 2,728 of those facilities were ultimately used for this report.

