How Reliable Is America's Electrical Grid?
Coal and natural gas are more reliable but they can't compete with massively subsidized wind and solar. That's a problem.
"We face unprecedented challenges to the reliability of our nation's electrical system." That was the testimony of Federal Energy Regulatory Commission (FERC) chairman Willie L. Phillips in a May 4, 2023, hearing of the Senate Committee on Energy and Natural Resources. FERC is the agency that regulates the interstate transmission and wholesale of electricity, and it is sounding the alarm about our electrical grid.
Until recently, Americans took electrical grid reliability for granted. "The average U.S. customer loses power less than two times per year for a total of less than five hours, which represents 99.95 percent reliability," notes National Renewable Energy Laboratory grid analyst Paul Denholm. But that may be changing.
Former FERC Commissioner James Danly pointed out during the hearing that a large part of the growing challenge to electrical grid reliability stems from the "premature retirement of the dispatchable generators"—those power sources, such as coal-fired and natural gas plants, that can be adjusted rapidly to meet electricity demand.
The "premature retirement" of those power sources is largely because of federal efforts to drastically cut greenhouse gas emissions from fossil fuel plants to combat climate change. The result? Always-on coal and gas plants cannot compete with massively subsidized intermittent wind and solar power.
"Our nation's grid infrastructure is nothing less than the backbone of the U.S. economy," stated then–FERC commissioner Allison Clements. That backbone, according to the Energy Information Administration, includes nearly 160,000 miles of high-voltage power lines, millions of low-voltage power lines, and distribution transformers that altogether connect 145 million customers.
Clements proposed addressing the looming reliability crisis by coming up with ways to "improve the efficiency of the existing grid via grid-enhancing technologies (GETs) and leverage the potential of distributed energy sources," such as wind and solar power. Deploying GETs, she argues, "would reduce the immediate need to build a more costly transmission line."
Assuming federal climate change policies persist, the Department of Energy estimates that the U.S. will need to increase its transmission capacity by 60 percent to 125 percent by the year 2035. The rise of power-hungry data centers, electric vehicles, and the electrification of home heating and cooling will increase domestic electricity demand by 18 percent by 2030 and 38 percent by 2035. Can GETs solve our self-inflicted grid reliability problem?
One key GET is new high-voltage transmission lines capable of conducting up to three times as much electricity as conventional lines. Traditional high-voltage lines use century-old technology: a steel core surrounded by aluminum wire. As current increases, these lines heat up and sag, which can cause them to touch brush or trees and spark damaging wildfires. This sagging also limits the amount of electricity that a line can carry.
Companies such as the California-based startup TS Conductor offer a promising solution. Their advanced transmission wires replace the steel core with carbon fiber, which is twice as strong, weighs 80 percent less, and barely sags when heated. This allows the carbon cores to support more tightly packed, flat trapezoidal aluminum wires, safely transmitting two to three times as much power as conventional lines.
Typically, securing permits for and building a new high-voltage transmission line takes about 10 years. But restringing existing lines with advanced conductors could double the current capacity of our transmission system in the near term, according to an April report on reconductoring by researchers at University of California, Berkeley, and the nonprofit GridLab. This approach avoids the costs and regulatory hurdles of new lines. The researchers calculated that "reconductoring projects typically cost less than half the price of new lines for similar capacity increases." Even new transmission would be cheaper, as stringing lighter lines requires fewer, less bulky towers.
A February companion working paper concludes that reconductoring existing rights-of-way "can rapidly and cost- effectively increase transmission capacity and unlock [renewable energy] on a US-wide scale," which would contribute over 80 percent of the new interzonal transmission needed to achieve over 90 percent of the federal government's clean electricity goals by 2035. The future of the U.S. electrical grid might hinge on these innovative solutions.
