Efficient transmission line upgrades could help decarbonize US power sector: Grid Strategies

Reconductoring about 50,000 miles of US transmission lines that will need to be replaced in the next decade with advanced conductors could accommodate an additional 27 GW of renewable capacity additions annually, power sector consulting firm Grid Strategies said March 15.

That increase in renewable capacity could drive down carbon dioxide emissions from the US power sector by an estimated 2.4 billion mt over the next 10 years, about 22 coal plants' worth of emissions, Grid Strategies said in report on behalf of several entities, including the American Council on Renewable Energy.

The consulting firm also found that making this switch to advanced reactors would save consumers at least $140 billion in energy costs over the decade.

"Transmission planning and selection processes, however, have not historically considered solutions that improve the operational efficiency of existing transmission hardware, leaving a significant opportunity to improve the efficiency of existing infrastructure on the table," Grid Strategies said.

Traditional conductors were built with steel cores that are less efficient than more modern advanced conductors, which are built around a composite or carbon core, according to Grid Strategies said. Advanced conductors offer "higher capacities and lower losses" compared with traditional technologies: They can also operate at higher temperatures for an extended period of time with low sag, allowing a "tremendous increase in the emergency (above normal or continuous ratings) loading capabilities," according to the report.

Jay Caspary, vice president of Grid Strategies and the lead author of the report, said regulators can act as barriers to deploying more efficient transmission technologies as they tend to focus on the upfront price more than the long-term benefits. Additionally, advanced conductors can help the US better manage climate events, he said during a March 15 webinar discussing the report.

"We see how stressed the grid is for extreme weather events, and the ability to move large amounts of power from regions unaffected by major storms could provide tremendous benefits to the loads and the customers that could be affected," Caspary said.

The Electric Reliability Council of Texas has seen new load showing up faster than before, which is almost as big of a problem as integrating new generation, said Woody Rickerson, ERCOT's vice president of system planning and weatherization, during the webinar.

As a result, the grid operator has focused more on longer-term resiliency rather than the least-cost options, Rickerson said.

"We see a shift already, and I think this kind of technology will fit into that really well," he said.

Recommendations

The Grid Strategies report included a slew of recommendations for state and federal regulators. Among them, it suggested that the Federal Energy Regulatory Commission establish independent transmission monitors in every region to consider ways to improve the system's efficiency, including through technology like advanced conductors.

FERC should also require transmission planners to use a futures-based planning process looking at "likely future scenarios and where additional renewable energy generation resources will likely be connected to the grid," Grid Strategies said.

The US Department of Energy could set a standard for conductors' efficiency and create reconductoring targets to promote decarbonization.

At the state level, the report suggested that regulators should focus less on a project's cost and more on the maximum net benefits it could provide over the long term. Additionally, state regulators could require utilities to analyze opportunities for advanced conductors and other similar technologies.

"We need to be thinking and planning for where the grid is going and not continuing incremental solutions that ultimately result in higher prices and more land use," Liza Reed, research manager of low-carbon technology policy at the Niskanen Center, a think tank based in Washington, said during the webinar.