Huge Expansion of Regional Electric Transmission Needed

The U.S. needs to undertake a massive build-out of electric transmission lines between regional grids in order to ensure adequate, reliable service during more frequent extreme weather events and prevent blackouts, a recent report from the North American Electric Reliability Corporation (NERC) concludes.

As the United States continues its transition to renewable energy sources such as wind and solar, as well as increasing battery storage, the reliability of the grid continues to face significant challenges. NERC’s findings stress that proactive planning and substantial increased investment in grid services and expansions that will allow regional grids to share their capacity during blizzards, heat waves, and other emergencies, are essential to maintain consistent electricity delivery, especially in regions particularly prone to extreme weather.

NERC is responsible for ensuring the reliability and security of the U.S. bulk electric system. That system is made up of six regional reliability organizations and 10 regional transmission organizations. The regional grid systems have only limited interconnections allowing power to flow from one grid to another, with some having a greater ability to share than others have.

The NERC study looked at electric adequacy by assuming that weather conditions from each of the 12 past years happened again in 2033, based on that year’s projected load and resource mix and current transmission capabilities. It also looked at the impact of adding additional transfer capability between regional grids to mitigate the effects of extreme weather conditions.

Among those weather events was Winter Storm Elliott in 2022, when extreme cold swept through the eastern U.S. and caused significant generation losses from frozen equipment and lowered gas pipeline pressures. Another extreme winter storm in Texas and the southern U.S. in 2021 led to widespread blackouts.

The NERC report suggests increasing transfer capacity by 35,000 megawatts (MW) and notes that even then demand would not be met in a few cases involving California’s grid. That is a huge amount of electricity, considering that the average generation of a nuclear power plant is slightly less than 1,000 MW. NERC also noted that the amount of transfer capability needed varied widely among regional providers, depending on their resource mix.

NERC's report highlights the urgent need for expanded transmission capacity to support the rapid growth of renewable energy projects. Wind and solar installations are often located in remote areas, and without sufficient transmission infrastructure, these projects face significant delays or cancellations. According to the U.S. Energy Information Administration (EIA), over 1,000 gigawatts (GW) of renewable energy and storage projects are currently waiting to connect to the grid.

In 2022, transmission spending reached $63 billion, a 9% increase from 2021, the EIA reports, yet this investment remains insufficient to address growing demands. The average wait time for renewable projects to gain grid connection approval now exceeds four years, further slowing deployment. Rising electricity demand, projected to grow 2% annually, and extreme weather events like heat waves and winter storms continue to strain the grid, increasing the risk of blackouts.