In the 1960s and 70s, the United States experienced a boom in transmission construction. At the time, most power plants being constructed were large, centrally located power plants, including coal, nuclear, and natural gas facilities. The transmission network was built largely to suit the needs of these centrally located power plants. However, the transmission built in the 1960s is now more than 50 years old, and the system now needs widespread maintenance, repair, and reconstruction.
The energy grid has changed drastically since the first boom in transmission construction; renewables now make up a large portion of energy production. Unlike the large, centrally located power plants that coincided with the transmission boom, renewables are located where they produce the most energy, which does not often coincide with the areas of most demand. This has created the need for new transmission investment. A growing body of research finds that decarbonization and increasing renewables will require significant transmission expansion and investment. According to the Brattle Group , an annual incremental transmission investment of $3 billion to $7 billion will be necessary to meet increased demand from electrification between 2018 and 2030. A different study by Princeton University found that the U.S. will need to expand transmission capacity by 60% by 2035 and triple it by 2050. In response to this changing energy landscape, the federal government and FERC have issued a series of new legislation and regulations to improve reliability and speed up the development of new transmission.