The issue
Transmission lines make up the highway system traveled by electricity as it moves from its generation source to the load centers where it is distributed to customers. A robust transmission system is key to ensuring a diverse generation mix (coal, wind, gas etc.) is available for use. It also facilitates interstate commerce and our national defense.
This sophisticated network has become increasingly important as our society has become so technology dependent. In order to keep pace with our growing needs, aging transmission infrastructure will need to be replaced and the current system expanded.
How we got to this point
Today’s electricity infrastructure is no longer intended to simply provide reliable electric service to local consumers. It supplies bulk power to wholesale markets across the country, stabilizing local economies and localized electricity prices. The capabilities of the existing transmission system are being stressed by load growth, integration of new generation resources and lack of investment. All of this stress causes major reliability concerns for the electric industry.
Developments such as FERC Order 888, which opened access to transmission to third parties in the mid-1990s, changed the system’s dynamics. The system is now facilitator of an electricity marketplace with many participants across wide geographic regions. This interconnected nature means reliability issues in one region of the country can have widespread effects in other regions.
The penetration of renewables into the existing grid is going to require transmission to take on an interstate highway. Typically, a disconnect exists between where generation resources, such as solar and wind farms, are located and where the electricity they generate is needed.
What the stakes are
Without new investment, the current transmission system will be hard pressed to meet demand and best utilize the diverse generation resources available. This may lead to supply shortage or to service interruptions. Prudent transmission planning must weigh all the new demands of the system and should be designed to supersede the mindset of local or sub-regional planning.
The need for EHV
Extra-high voltage (EHV) infrastructure should be considered as a solution for meeting growing demand and facilitating the integration of renewable resources. These EHV lines are more energy efficient, meaning less voltage is lost in the transmission process. By introducing more of these lines, we can achieve a more reliable, flexible, and efficient transmission system. For example, one 765 kV line can carry as much power as three 500 kV lines or six 345 kV lines, meaning fewer will have to be constructed to achieve the same results. Of AEP’s 39,059 miles of transmission, 8,139 are extra-high voltage lines.
AEP position
AEP believes the nation’s transmission system must be developed as a robust interstate system, much like the nation’s highways, to connect regions, states and communities. Our highly efficient and reliable 765 kV network provides a strong foundation for this system because it is the most efficient, proven transmission technology available in United States.
