High-voltage electricity moves long distances through the transmission system. Transmission lines interconnect to form a network. Should one line fail, another will take over the electricity load. Transmission lines can be overhead or underground.

All transmission lines carry three-phase current, or three separate streams of electricity traveling along three separate conductors (see diagram 3).

A typical transmission system is interconnected with transmission systems of other electricity providers. That way we can receive an emergency supply of electricity or, if another company needs our electricity, we can send them power.

From the transmission lines, electricity goes to substations.

• Power Plant
• Transmission
• Substation
• Distribution
• Customer

TXU Energy (REP Certificate No. 10004) and Luminant are not the same company as Oncor Electric Delivery and are not regulated by the Public Utility Commission of Texas, and you do not have to buy TXU Energy's or Luminant's products to continue to receive quality regulated services from Oncor Electric Delivery.