Transmission Service Types

Access application forms, rates, business practices, and other documents related to the transmission services offered under the ISO Tariff (see Section II: Open Access Transmission Tariff) for moving power within, into, out of, or through the New England Balancing Authority Area (BAA).

For New Service or Service Changes

• If you have not done business with ISO New England before, please see the Transmission Service Applications page.
• If you’re already an ISO customer, see Transmission Service Types and Applications to find out how to apply for changes to—or additional—transmission-related services.

Overview of Transmission Service in New England

As the Regional Transmission Organization, one of the ISO’s responsibilities is overseeing and coordinating transmission of electric power within, into, out of, or through the New England BAA. This is the collection of generation, transmission, and loads within metered boundaries spanning Connecticut, Rhode Island, Massachusetts, New Hampshire, Vermont, and Maine (excluding the portions of Maine included within the Maritimes BAA). The transmission facilities within the New England BAA include pool transmission facilities, non-pool transmission facilities, merchant transmission facilities, and other transmission facilities.

Several types of transmission services are available in New England, including the following:

• Regional Network Service (RNS) to use the pool transmission facilities to move electricity into or within the New England BAA
• Through or Out Service (T/Out) to use the pool transmission facilities to move electricity out of or through the New England BAA
• Local Transmission Service to use the non-pool transmission facilities to move electricity over a local network located within the New England BAA
• CSC Transmission Service to use the Cross-Sound Cable (CSC) tie line to move electricity into, out of, or through the New England BAA
• Phase I/II Transmission Service to use the Phase I/II tie line to move electricity into, out of, or through the New England BAA
• Generator Interconnection to connect a generator to New England’s transmission system to be able to obtain service and move energy
• Transmission Upgrades to request an addition to, upgrade of, or modification of either the pool transmission facilities or the non-pool transmission facilities

Learn more about transmission service in New England by reviewing:

• ISO OATT Business Practices Section 1—OATT Transmission Services Summary
• ISO OATT Business Practices Section 2—RNS+T/Out Rates & Application