Increasing Efficiency Through Power Line Reconductoring, with Umed Paliwal

Power lines and transmission towers silhouetted against a blue-green sky.

Reconductoring–or rewiring–power lines with advanced conductive materials will reduce electricity waste and lower fossil fuel emissions.  Image credit: Photo by Fré Sonneveld on Unsplash.

Script & Audio by:  Sia Agarwal  |  Blurb by: Ashley Carter

Reconductoring power grids to boost energy efficiency

The expansion of renewable energy has resulted in a heightened need for greater transmission capacity of the electrical grid. Unfortunately, permitting and cost allocation have been large hurdles to the potential of rapid expansion to meet future demand. As an alternative, large-scale reconductoring of advanced conductor systems has been proposed as a solution. Such an alternative can double transmission capacity cost-effectively, without the need to ensure additional permitting. In order to achieve this transition, old steel power lines would be replaced with carbon fiber, reducing electricity loss and boosting the overall capacity of the power grid. 

How does reconductoring work?

In order to achieve clean energy goals, it is vital that we increase power grid capacity. To briefly summarize, electrons travel along transmission lines between towers made of conducting elements and a strength member, which allows conductors to hang between towers. The most common type of reinforcement is ACSR, aluminum conductor steel reinforced, used in overhead electrical transmissions. ACSR is susceptible to degradation and breakage, which may lead to more frequent power outages and increased chemical runoff into the environment. As an alternative, ACSS has been proposed by researchers as it carries more current than ACSR and is supported at higher temperatures. 

According to recent studies by the Goldman School and GridLab, replacing power lines with advanced conductors would enable 90% clean electricity by 2035. The report revealed that reconductoring transmission lines could add approximately 65 TW-miles of new interzonal transmission capacity in ten years, compared to 16TW-miles from building only new transmission lines. In terms of pricing, implementing advanced conductors costs around 20% more than building new lines. Yet replacing old lines with advanced conductors is typically half the cost than building new lines for the same capacity, partly because you reuse old infrastructure and the new models are much more energy efficient. Further policy and legislation is necessary in order to drive this technology into the future and ensure proper permitting, funding, and planning. 

What are some of the benefits?

Advanced composite-core conductors such as ACSS can carry double the existing capacity, operate at higher temperatures, and reduce line sag. Further, replacing the steel for a stronger yet smaller composite-based core can avoid the construction of new lines which bring about land acquisition and increasing permitting. There is already a growing movement towards reconductoring, as 90,000 miles of advanced conductors have been deployed globally. More advanced conductors also have the benefit of being cost-effective, with an estimated $180 billion in systems cost savings with more long-term structure. Advanced conductors enable a doubling of line capacity at less than half the cost of new lines. Alongside the benefits, at large, reconductoring can play a pivotal role in low-cost decarbonization of power systems.

What are some of the drawbacks?

Amidst the potential advantages are obstacles that may impede the future progress of reconductoring. First, there is a lack of awareness. Conventionally, the only way to expand the grid capacity has been to build new lines. Utilities are not aware of the existing solution and often fail to take reconductoring into account. Alongside this is a lack of experience and misconception that implementing reconductoring lines is difficult and unrealistic. As there is a lack of incentives for utilities to improve their products, cheaper solutions are not enticing for their rate of return regulation. Particularly if reconductoring only occurs in localized areas as opposed to system-wide implementation, the benefits may be limited. Thus, government prioritization of this new solution is critical in order to boost conductor efficiency.

About our guest

Umed Paliwal is a senior scientist at the Center for Environmental Public Policy and the Goldman School of Public Policy at UC Berkeley. Umed conducts research on ways to integrate renewables on the grid and understand its impact on reliability and energy pricing. Umed’s research has revealed that replacing old power lines with newer technology can boost the capacity of the power grid and help to achieve clean energy goals. He holds a Master of Public Policy from UC Berkeley where he focused on energy markets, regulation, power systems modeling and data analytics. 

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Transcript

Ethan: I’m Ethan Elkind, and you’re listening to Climate Break: climate solutions in a hurry. Today’s proposal? Reconductoring transmission lines to improve efficiency and boost renewable energy. We spoke to Umed Paliwal, a senior scientist at UC Berkeley, who explains what reconductoring is.

Mr. Paliwal: So reconductoring is replacing the wires of an existing power line with newer wires that are made up of advanced materials. Now, these newer advanced wires, uh, they can carry double the amount of electricity as compared to the conventional ones. 

Ethan: Made of a strong carbon fiber, advanced power lines help reduce electrical losses along power lines. 

Mr. Paliwal: They’re almost 25 to 50 percent lower, uh, than these conventional wires.

Ethan: Compared to building entirely new transmission towers and lines, reconductoring lines saves both money and time. 

Mr. Paliwal: It costs half as much as of building new transmission lines, and it can be done in one to two years. 

Ethan: He says that 100,000 miles of advanced power lines already installed globally are helping to reduce greenhouse gas emissions. 

Mr. Paliwal: And that saves a lot of emissions, a lot of fuel, a lot of water also. Which is also very overlooked because, uh, these thermal power plants do require a lot of water to operate. 

Ethan: Paliwal’s research shows that reconductoring can open untapped capacity for new solar and wind facilities that could be located near existing power lines.

Mr. Paliwal: We estimated how much renewable capacity is estimated within five miles of the existing transmission lines and that is like two orders of magnitude higher than the electricity that the US would need by 2050.

Ethan: To learn more about reconductoring power lines and Paliwal’s research, visit climatebreak.org

Increasing Efficiency Through Power Line Reconductoring, with Umed Paliwal