PJM is the Eastern Regional Transmission Interconnection. This renewable energy region consists of all or part of 13 US States and the District of Columbia.

US States: Delaware, Illinois, Indiana, Kentucky, Maryland, Michigan, New Jersey, North Carolina, Ohio, Pennsylvania, Tennessee, Virginia, West Virginia, and the District of Columbia.

PJM GATS: is the Generation Attribute Tracking System. GATS is a renewable energy tracking system that assists in the transfer, documentation, verification, and authenticity of Renewable Energy Certificates (RECs) and environmental credits.

MISO (M-RETS) is the Mid-Western Independent Transmission System Opertor, Inc.'s Midwest Renewable Energy Tracking System. This renewable energy region consists of all or part of 13 US States and one Canadian Province.

US States: Illinois, Indiana, Iowa, Kentucky, Michigan, Minnesota, Missouri, Montana, North Dakota, Ohio, Pennsylvania, South Dakota, and Wisconsin.

Canadian Province: Manitoba.

M-RETS is the Midwest Renewable Energy Tracking System. This is a renewable energy tracking system that assists in the transfer, documentation, verification and authenticity of Renewable Energy Certificates (RECs) and environmental credits.

ERCOT is the Electric Reliability Council of Texas. Formed in 1970, it is one of eight Independent System Operators (ISOs) in North America, and one of nine regional electric reliability councils under the authority of the North American Electric Reliability Corporation (NERC).

The ERCOT region occupies the entire Texas Interconnection, which is nearly all of the state of Texas. Unlike the other major NERC interconnections, the high voltage transmission and energy market within the Texas Interconnection is operated by ERCOT as essentially a single power system instead of as a network of cooperating utility companies.

NARR is the North American Renewables Registry. The primary role of the registry is to provide REC origination for clean generation facilities located in states and provinces not covered by the five current regional systems: NEPOOL (GIS), PJM (GATS), ERCOT, MISO (M-RETS), and WREGIS. The purpose is to complement the existing market systems and provide complete North American coverage for renewable energy markets. NARR is operated by APX, Inc.

NEPOOL is the New England Regional Transmission Interconnection. This renewable energy region consists of all or part of 6 US States.

US States: Connecticut, Maine, Massachusetts, New Hampshire, Vermont, and Rhode Island.

NEPOOL GIS: is the New England Power Pool Generation Information System. NEPOOL GIS is a renewable energy tracking system that assists in the transfer, documentation, verification and authenticity of Renewable Energy Certificates (RECs) and environmental credits.

WREGIS is the Western Regional Transmission Interconnection. This renewable energy region consists of all or part of 14 US States, 2 Canadian Provinces, and 1 Mexican Territory.

US States: Arizona, California, Idaho, Montana, Nebraska, Nevada, New Mexico, Oregon, South Dakota, Texas, Utah, Washington, and Wyoming.

Canadian Provinces: Alberta & British Columbia.

Mexican Territory: Baja California.

WREGIS is Western Renewable Energy Generation Information System. WREGIS is a renewable energy tracking system that assists the transfer, documentation, verification, and authenticity of Renewable Energy Certificates (RECs) and environmental credits.