One of the biggest obstacles to expanding clean energy in the United States is the lack of power lines. Building new transmission lines could take more than a decade because of delays and local opposition. But two reports published Tuesday suggest there may be a faster, cheaper solution.
Replacing existing power lines with cables made from cutting-edge materials could roughly double grid capacity in many parts of the country, making room for significantly more wind and solar power.
This technique, known as “advanced reconstruction,” is also widely used in other countries. But many U.S. utilities have been slow to embrace it due to unfamiliarity with the technology, as well as regulatory and bureaucratic hurdles, researchers found.
“We were very surprised to see how significantly the capacity could be increased through reconduction,” said Amol Phadke, a senior scientist at the University of California, Berkeley, who contributed to one of the reports published Tuesday. Berkeley researchers worked with consulting firm GridLab to investigate what would happen if advanced reconfiguration techniques were widely adopted.
“This is not everything we need to do to upgrade the grid, but it can be a major part of the solution,” Dr. Phadke said.
Most power lines today consist of a steel core surrounded by aluminum strands, a design that has been around for 100 years. In the 2000s, several companies developed cables that used smaller, lighter cores, such as carbon fiber, and could accommodate more aluminum. These advanced cables can carry up to twice as much current as previous models.
Replacing old lines can be done relatively quickly. In 2011, Texas utility AEP urgently needed to provide more power to the Lower Rio Grande Valley to meet skyrocketing population growth. It would have taken too long to acquire land and permits and build towers for new transmission lines. Instead, AEP replaced 240 miles of existing line wire with advanced conductors, a task that took less than three years and increased the line's carrying capacity by 40 percent.
In many places, upgrading power lines with advanced conductors can nearly double the capacity of existing transmission corridors at less than half the cost of building new lines, researchers have found. If utilities begin deploying advanced conductors on a national scale, including replacing thousands of miles of power lines, they could add four times more transmission capacity by 2035 than at current rates.
This would allow thousands of proposed projects to use far more solar and wind power, but they cannot move forward because local power grids are too clogged to accommodate them.
Shinjini Menon, vice president of asset management and wildfire safety at Southern California Edison, one of the nation's largest corporations, said installing advanced conductors is a promising idea, but questions how much additional wind and solar power can be built near existing lines. He said there are still some left. utility. Power companies will still have to build many new lines to reach windier and sunnier, more remote areas, she said.
“We agree that a high-quality conductor would be very useful,” Mr. Menon said. His company has already embarked on several re-evangelization projects in California. “But how far can we go? “The jury is still out.”
Experts generally agree that the slow rollout of the power grid is the Achilles' heel of the transition to clean energy. The Department of Energy estimates that the nation's transmission line network will need to expand by more than two-thirds by 2035 to meet President Biden's goal of powering the nation with clean energy.
But building transmission lines has become a brutal task, and it can take more than a decade for developers to lay new lines across multiple counties, obtain permits from a patchwork of agencies and resolve lawsuits over damaged views or ecological damage. Last year, the U.S. added 251 miles of high-voltage transmission lines, a number that has been declining over the past decade.
Climate-related risks are high. In 2022, Congress approved hundreds of billions of dollars for solar panels, wind turbines, electric vehicles and other non-polluting technologies to combat global warming as part of the Inflation Reduction Act. But if the United States cannot add new transmission capacity faster, roughly half of the emissions reductions expected from that law may not be realized, researchers with the Princeton-led REPEAT project found.
The challenges of building new lines have led many energy experts and industry officials to look at ways to squeeze more out of the existing grid. These include “grid hardening technologies,” such as sensors that allow utilities to send more power over existing lines without overloading them, and advanced controls that allow operators to ease congestion on the grid. Studies show that these technologies can increase grid capacity by 10 to 30 percent at low cost.
Emilia Chojkiewicz, one of the authors of the Berkeley report, said countries such as Belgium and the Netherlands have been deploying advanced conductors widely to integrate more wind and solar power.
“We talked to the transmission system planners there and they all said this is a given,” Chojkiewicz said. “It’s often difficult to get a new right-of-way for a line, and reconveyance is much quicker.”
If reconduction is so effective, why aren't more utilities in the U.S. doing it? This question was the focus of a second report released Tuesday by the nonprofit groups GridLab and Energy Innovation.
One problem is the fragmented nature of the U.S. power system, which actually consists of three power grids operated by 3,200 different utilities and a complex patchwork of regional planners and regulators. This means that new technologies that require careful research and worker retraining sometimes spread more slowly than in countries with fewer grid operators.
“A lot of utilities are risk averse,” said Dave Bryant, CTO of CTC Global, an advanced conductor manufacturer with projects in more than 60 countries.
There are also misaligned incentives, the report said. Because of the way utilities are compensated, there is often more financial incentive to build new lines than to upgrade existing equipment. Conversely, some regulators are wary of the high initial cost of premium carcasses, even if they pay off in the long run. Additionally, many utilities have little incentive to cooperate with each other on long-term transmission plans.
“The biggest barrier is that industry and regulators are still caught up in a short-term, reactive mindset,” said Casey Baker, senior program manager at GridLab. “But now we are in an era where the grid is expected to grow very quickly, and existing processes are not keeping up with that reality.”
Change may begin in some places. In Montana, Northwestern Energy recently replaced some of its aging lines with higher-quality conductors to reduce wildfire risk. New tracks sag less in the heat and are less likely to come into contact with trees. Satisfied with the results, Montana lawmakers passed a bill giving utilities financial incentives to install advanced conductors. The Virginia bill would require utilities to consider the technology.
As new data centers, factories and electric vehicles begin to surge power demand for the first time in 20 years and create bottlenecks in the grid, many utilities are overcoming their wariness about new technology.
“There is a lot more interest in grid enhancement technologies, whether re-conducting or other options,” said Pedro Pizarro, president and CEO of California utility Edison International and chairman of the Edison Electric Institute. Utility trade organization. “There is a sense of urgency.”