Transmission owner (TO)

In markets where the system operations function has been moved to an Independent System Operator (ISO), the term transmission owner, or TO, is used to describe the entity that continues to own, maintain, and expand the transmission system when necessary. The TO operates the transmission system under direction from the ISO and receives revenues from the ISO to cover the cost of ownership and expenses of operation. TOs may be transcos or they may be part of a utility company.