EEI > Issues & Policy > Transmission
The electric transmission network is the backbone of the nation’s energy grid and consists of more than 600,000 circuit miles of lines, 240,000 of which are considered high-voltage lines (230 Kilovolts and greater). These lines link the generators of electricity to the distributors, transporting electricity to local electric companies, which in turn deliver it to customers.

The transmission network provides a range of benefits that ultimately accrue to customers in the form of reliable service and a reduction in costs, by:  improving power flow and relieving congestion, facilitating robust wholesale market competition, enabling a diverse and changing energy portfolio, and mitigating damage and limiting customer outages during severe weather events and other major disruptions to the system.

Transmission Infrastructure Investment

Members of the Edison Electric Institute (EEI) are committed to investing in the smarter energy infrastructure needed to deliver America’s energy future. EEI’s member companies invested $21.9 billion in transmission infrastructure in 2017 and expect to invest an additional $89 billion in the transmission system through 2021 to make it more efficient, more dynamic, and more secure and to continue to provide customers with the affordable, reliable, safe, and increasingly clean energy they need. 

The energy grid is one of the nation’s most capital-intensive assets, and EEI member companies require shareholder support in the form of capital investment and regulatory support in the form of sound ratemaking policy in order to build, own, and operate the transmission infrastructure that ensures reliable and affordable service to customers.

Significant replacements and/or upgrades are required now and in coming years to maintain and to improve system performance. Extensive investments also are needed to integrate new renewable and distributed energy resources and to respond to a rapidly changing energy mix. At the same time, EEI’s members continue to invest in the transmission system to maintain and to improve its resiliency against both cyber and physical threats. These transmission investments help to save customers money over the long term by connecting them with lower-cost generation, reducing overall system costs, and providing a variety of economic benefits at the regional and local levels.